Placenta Praevia and Placenta Accreta: Diagnosis and Management: Green‐top Guideline No. 27a

Population studies have shown that placenta accreta spectrum remains undiagnosed before delivery in one-half to two-thirds of cases.

“Population studies have shown that placenta accreta spectrum remains undiagnosed before delivery in one-half 136 to two-thirds of cases.120”

• cites [136] 136. Bailit JL, Grobman WA, Rice MM, Reddy UM, Wapner RJ, Varner MW, et al.; Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units (MFMU) Network. Morbidly adherent placenta treatments and outcomes. Obstet Gynecol 2015;125:683-9. sourceDisputed

  Citation 120 is attached to the two-thirds figure, but the Results report that 53.2% of cases were suspected before delivery, leaving 46.8% unsuspected. The Discussion likewise says about half were suspected. This source supports an undiagnosed proportion near one-half, not two-thirds. (LLM, conf=0.88)

  Checked by a reasoning model — may be wrong.

  Experimental — accuracy not yet measured
• cites [120] 120. Thurn L, Lindqvist PG, Jakobsson M, Colmorn LB, Klungsoyr K, Bjarnad ottir RI, et al. Abnormally invasive placenta-prevalence, risk factors and antenatal suspicion: results from a large population-based pregnancy cohort study in the Nordic countries. BJOG 2016;123:1348-55. sourceNot checked — no full text of the source

Compared with vaginal birth, a previous prelabour caesarean section is associated with an increased risk of placenta praevia in the second delivery (aOR 2.62, 95% CI 1.24-5.56).

“Compared with vaginal birth, a previous prelabour caesarean section is associated with an increased risk of placenta praevia in the second delivery (adjusted OR [aOR] 2.62, 95% CI 1.24-5.56).27”

• cites [27] 27. Downes KL, Hinkle SN, Sjaarda LA, Albert PS, Grantz KL. Previous prelabor or intrapartum cesarean delivery and risk of placenta previa. Am J Obstet Gynecol 2015;212:669.e1-6. sourceSupported

ART is associated with a higher incidence of placenta praevia independent of the high rate of multiple pregnancies generated by the technique.

“ART is associated with a higher incidence of placenta praevia independent of the high rate of multiple pregnancies generated by the technique used.30,31”

• cites [30] 30. Grady R, Alavi N, Vale R, Khandwala M, McDonald SD. Elective single embryo transfer and perinatal outcomes: a systematic review and meta-analysis. Fertil Steril 2012;97:324-31. sourceNot checked — no full text of the source
• cites [31] 31. Korosec S, Ban Frangez H, Verdenik I, Kladnik U, Kotar V, Virant-Klun I, et al. Singleton pregnancy outcomes after in vitro fertilization with fresh or frozen-thawed embryo transfer and incidence of placenta praevia. Biomed Res Int 2014;2014:431797. sourceSupported

Apparent placental 'migration' following development of the lower uterine segment during the third trimester results in resolution of the low-lying placenta in 90% of cases before term.

“Apparent placental 'migration' following the development of the lower uterine segment during the third trimester of pregnancy results in the resolution of the low-lying placenta in 90% of the cases before term.[38][39][40][41][42][43][44][45][46]”

• cites [38] 38. Dashe JS, McIntire DD, Ramus RM, Santos-Ramos R, Twickler DM. Persistence of placenta previa according to gestational age at ultrasound detection. Obstet Gynecol 2002;99:692-7. sourceNot checked — no full text of the source
• cites [39] 39. Cho JY, Lee YH, Moon MH, Lee JH. Difference in migration of placenta according to the location and type of placenta previa. J Clin Ultrasound 2008;36:79-84. sourceNot checked — no full text of the source
• cites [40] 40. Eichelberger KY, Haeri S, Kessler DC, Swartz A, Herring A, Wolfe HM. Placenta previa in the second trimester: sonographic and clinical factors associated with its resolution. Am J Perinatol 2011;28:735-9. sourcePartly supported

  The Results report that 90% of placenta previas had resolved by 34 4/7 weeks, before term. However, that figure covers complete and marginal previas together; 98% of marginal previas resolved. The paper does not attribute resolution to placental “migration” caused by development of the lower uterine segment. (LLM, conf=0.87)

  Experimental — accuracy not yet measured

A randomised double-blind placebo-controlled multicentre trial of 109 women at 24+0 to 33+6 weeks with placenta praevia bleeding and intact membranes showed no difference in prolongation of pregnancy between nifedipine and placebo.

“A randomised, double-blind, placebo-controlled multicentre trial including 109 women at 24 +0 to 33 +6 weeks with at least one episode of placenta praevia bleeding and intact membranes has shown that there was no difference in the prolongation of pregnancy between the nifedipine (n = 54) and placebo (n = 55) groups.70”

• cites [70] 70. Verspyck E, de Vienne C, Muszynski C, Bubenheim M, Chanavaz-Lacheray I, Dreyfus M, et al. Maintenance nifedipine therapy for preterm symptomatic placenta previa: A randomized, multicenter, double-blind, placebo-controlled trial. PLoS One 2017;23:e0173717. sourceSupported

Cervical length is a predictor of antepartum bleeding and emergency preterm caesarean section in placenta praevia.

“cohort studies with low risks of confounding bias have shown that cervical length is a predictor of antepartum bleeding and emergency preterm caesarean section in placenta praevia.[57][58][59][60]”

• cites [57] 57. Ghi T, Contro E, Martina T, Piva M, Morandi R, Orsini LF, et al. Cervical length and risk of antepartum bleeding in women with complete placenta previa. Ultrasound Obstet Gynecol 2009;33:209-12. sourcePartly supported

  The Results report that shorter cervical length predicted emergency Cesarean section before 34 weeks due to massive hemorrhage in women with complete placenta previa. But cervical length did not differ significantly between women with and without prepartum bleeding (P = 0.18), so the broader claim that it predicts antepartum bleeding is not supported. Page numbers were not provided in our copy. (LLM, conf=0.91)

  Experimental — accuracy not yet measured
• cites [58] 58. Zaitoun MM, El Behery MM, Abd El Hameed AA, Soliman BS. Does cervical length and the lower placental edge thickness measurement correlates with clinical outcome in cases of complete placenta previa? Arch Gynecol Obstet 2011;284:867-73. sourceNot checked — no full text of the source
• cites [59] 59. Mimura T, Hasegawa J, Nakamura M, Matsuoka R, Ichizuka K, Sekizawa A, et al. Correlation between the cervical length and the amount of bleeding during cesarean section in placenta previa. J Obstet Gynaecol Res 2011;37:830-5. sourceNot checked — no full text of the source

The 2016 RCT found that administration of betamethasone to women with a singleton pregnancy at risk for late preterm delivery (34+0 to 36+5 weeks of gestation) significantly reduces the rate of neonatal respiratory complications.

“The 2016 RCT has found that the administration of betamethasone to women with a singleton pregnancy at risk for late preterm delivery (34 +0 to 36 +5 weeks of gestation) significantly reduces the rate of neonatal respiratory complications.67”

• cites [67] 67. Gyamfi-Bannerman C, Thom EA, Blackwell SC, Tita AT, Reddy UM, Saade GR, et al.; NICHD Maternal-Fetal Medicine Units Network. Antenatal betamethasone for women at risk for late preterm delivery. N Engl J Med 2016;374:1311-20. sourceSupported

'Migration' of placenta praevia is still possible after 32 weeks of gestation.

“However, 'migration' is still possible after 32 weeks of gestation.50,51”

• cites [50] 50. Becker RH, Vonk R, Mende BC, Ragosch V, Entezami M. The relevance of placental location at 20-23 gestational weeks for prediction of placenta previa at delivery: evaluation of 8650 cases. Ultrasound Obstet Gynecol 2001;17:496-501. sourceNot checked — no full text of the source
• cites [51] 51. Oppenheimer L, Holmes P, Simpson N, Dabrowski A. Diagnosis of low-lying placenta: can migration in the third trimester predict outcome? Ultrasound Obstet Gynecol 2001;18:100-2. sourceSupported

Adverse perinatal outcomes were comparable between nifedipine and placebo groups in that trial.

“Adverse perinatal outcomes were comparable between groups.”

• cites [70] 70. Verspyck E, de Vienne C, Muszynski C, Bubenheim M, Chanavaz-Lacheray I, Dreyfus M, et al. Maintenance nifedipine therapy for preterm symptomatic placenta previa: A randomized, multicenter, double-blind, placebo-controlled trial. PLoS One 2017;23:e0173717. sourceSupported

Women with a cervical length of less than 31 mm have a 16 times higher risk of emergency caesarean section due to massive haemorrhage (OR 16.4, 95% CI 3.4-75.9).

“Women with a cervical length of less than 31 mm have a 16 times (OR 16.4, 95% CI 3.4-75.9)higher risk of emergency caesarean section due to massive haemorrhage.57”

• cites [57] 57. Ghi T, Contro E, Martina T, Piva M, Morandi R, Orsini LF, et al. Cervical length and risk of antepartum bleeding in women with complete placenta previa. Ultrasound Obstet Gynecol 2009;33:209-12. sourcePartly supported

  The Results report an odds ratio of 16.36 (95% CI, 3.39–75.92) for Cesarean delivery due to massive hemorrhage, matching the claim’s rounded figures. The reported cutoff is cervical length ≤31 mm, not <31 mm, and the outcome is specifically preterm emergency Cesarean section before 34 weeks; the citing sentence omits that timing qualifier. (LLM, conf=0.87)

  Experimental — accuracy not yet measured

A combined method of B-Lynch suture and intrauterine balloon has been successfully used in preventing PPH in placenta praevia.

“A combined method of B-Lynch suture and the intrauterine balloon has also been successfully used in preventing PPH in placenta praevia.105”

• cites [105] sourcePartly supported

  The Results (page unavailable) report that the combined suture-and-balloon procedure controlled bleeding without further surgery; 10 of 11 women had placenta previa, and two received B-Lynch sutures. But these women generally already had postpartum hemorrhage, and the Discussion (page unavailable) describes only one prophylactic use to prevent further bleeding. The paper therefore supports successful treatment in this setting, not the broader claim that B-Lynch plus balloon prevented PPH. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

The recent case-control study from the NICHD/MFMU Network Cesarean Section Registry found general anaesthesia to be one of the main factors associated with maternal haemorrhage in women with placenta praevia.

“The recent case-control study from the NICHD/MFMU Network Cesarean Section Registry found general anaesthesia to be one of the main factors associated with maternal haemorrhage in women with placenta praevia.86”

• cites [86] 86. Gibbins KJ, Einerson BD, Varner MW, Silver RM. Placenta previa and maternal haemorrhagic morbidity. J Matern Fetal Neonatal Med 2018;31:494-9. sourceSupported

Case series on intrauterine hydrostatic balloon catheters, including Bakri balloon, BT-Cath balloon or Sengstaken-Blakemore tube, in women with placenta praevia have reported success in controlling PPH ranging from 75% to 88%.

“Case series on the use of intrauterine hydrostatic balloon catheters, including the Bakri balloon, [97][98][99][100][101] the BT-Cath â balloon 102 or the Sengstaken-Blakemore tube, 103 in women with placenta praevia have reported success in controlling PPH ranging from 75% to 88%.”

• cites [97] 97. Kumru P, Demirci O, Erdogdu E, Arısoy R, Ertekin AA, Tugrul S, et al. The Bakri balloon for the management of postpartum hemorrhage in cases with placenta previa. Eur J Obstet Gynecol Reprod Biol 2013;167:167-70. sourceNot checked — no full text of the source
• cites [98] 98. Beckmann MM, Chaplin J. Bakri balloon during cesarean delivery for placenta previa. Int J Gynaecol Obstet 2014;124:118-22. sourceNot checked — no full text of the source
• cites [99] 99. Cho HY, Park YW, Kim YH, Jung I, Kwon JY. Efficacy of intrauterine Bakri balloon tamponade in cesarean section for placenta previa patients. PLoS One 2015;10:e0134282. RCOG Green-top Guideline No. 126 e40 of e48 ª 2018 Royal College of Obstetricians and Gynaecologists 14710528, 2019, 1, Downloaded from https://obgyn.onlinelibrary.wiley.com/doi/10.1111/1471-0528.15306, Wiley Online Library on [01/09/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons L sourceSupported

Main factors associated with maternal haemorrhage in women with placenta praevia include pre-delivery anaemia, thrombocytopenia, diabetes and magnesium use.

“the main factors associated with maternal haemorrhage include pre-delivery anaemia, thrombocytopenia, diabetes and magnesium use.86”

• cites [86] 86. Gibbins KJ, Einerson BD, Varner MW, Silver RM. Placenta previa and maternal haemorrhagic morbidity. J Matern Fetal Neonatal Med 2018;31:494-9. sourceSupported

Success rates of vaginal delivery when the placental edge is between 10 and 20 mm from the internal os vary widely (56% and 93%).

“the success rates of vaginal delivery when the placental edge is between 10 and 20 mm from the internal os vary widely (56% and 93%, respectively).[79][80][81][82]”

• cites [79] 79. Vergani P, Ornaghi S, Pozzi I, Beretta P, Russo FM, Follesa I, et al. Placenta previa: distance to internal os and mode of delivery. Am J Obstet Gynecol 2009;201:266.e1-5. sourceNot checked — no full text of the source
• cites [80] 80. Nakamura M, Hasegawa J, Matsuaka R, Mimura T, Ichizuka K, Sekizawa A, et al. Amount of hemorrhage during vaginal delivery correlates with length from placental edge to external os in cases with low-lying placenta whose length between placental edge and internal os was 1-2 cm. J Obstet Gynaecol Res 2012;38:1041-5. sourceNot checked — no full text of the source
• cites [81] 81. Al Wadi K, Schneider C, Burym C, Reid G, Hunt J, Menticoglou S. Evaluating the safety of labour in women with a placental edge 11 to 20 mm from the internal cervical Os. J Obstet Gynaecol Can 2014;36:674-7. sourcePartly supported

  The Results report that 13 of 14 women (92.9%) with a placental edge 11–20 mm from the internal os delivered vaginally after a trial of labour, supporting the 93% figure. This paper does not report a 56% success rate; the other rate it discusses for this distance is 76.5% (Discussion). (LLM, conf=0.86)

  Experimental — accuracy not yet measured

The major risk factors for placenta accreta spectrum are history of accreta in a previous pregnancy, previous caesarean delivery and other uterine surgery, including repeated endometrial curettage.

“The major risk factors for placenta accreta spectrum are history of accreta in a previous pregnancy, previous caesarean delivery and other uterine surgery, including repeated endometrial curettage.”

• cites [111] 111. Wu S, Kocherginsky M, Hibbard JU. Abnormal placentation: twenty-year analysis. Am J Obstet Gynecol 2005;192:1458-61. sourceNot checked — no full text of the source
• cites [112] 112. Silver RM, Landon MB, Rouse DJ, Leveno KJ, Spong CY, Thom EA, et al.; National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Maternal morbidity associated with multiple repeat cesarean deliveries. Obstet Gynecol 2006;107:1226-32. sourceNot checked — no full text of the source
• cites [113] 113. Fitzpatrick KE, Sellers S, Spark P, Kurinczuk JJ, Brocklehurst P, Knight M. Incidence and risk factors for placenta accreta/increta/ percreta in the UK: a national case-control study. PLoS One 2012;7:e52893. 114. 103. Morlando M, Sarno L, Napolitano R, Capone A, Tessitore G, Maruotti GM, et al. Placenta accreta: incidence and risk factors in an area with a particularly high rate of cesarean section. Acta Obstet Gynecol Scand 2013;92:457-60. sourcePartly supported

  The Results > Risk factors section reports increased odds of placenta accreta/increta/percreta after a previous caesarean delivery or other uterine surgery; its table note includes dilation and curettage among those surgeries. The paper does not identify prior accreta as a risk factor or assess repeated endometrial curettage separately. Page numbers are unavailable in our copy. (LLM, conf=0.87)

  Experimental — accuracy not yet measured

Maternal haemorrhagic morbidity is more common in women with praevia (19% versus 7%, adjusted RR 2.6, 95% CI 1.9-3.5).

“maternal haemorrhagic morbidity is more common in women with praevia (19% versus 7%, adjusted RR 2.6, 95% CI 1.9-3.5)”

• cites [86] 86. Gibbins KJ, Einerson BD, Varner MW, Silver RM. Placenta previa and maternal haemorrhagic morbidity. J Matern Fetal Neonatal Med 2018;31:494-9. sourceSupported

Women with a third trimester placental edge less than 20 mm from the internal os are more likely to need caesarean delivery when the placental edge is thicker (over 10 mm) and/or contains a sponge-like echo or marginal sinus.

“Women presenting with a placental edge less than 20 mm from the internal os in the third trimester are more likely to need delivery by caesarean section when the placental edge is thicker (over 10 mm) 75,76 and/or contains a sponge-like echo 77 or marginal 'sinus'.78”

• cites [75] 75. Bhide A, Prefumo F, Moore J, Hollis B, Thilaganathan B. Placental edge to internal os distance in the late third trimester and mode of delivery in placenta praevia. BJOG 2003;110:860-4. sourceNot checked — no full text of the source
• cites [76] 76. Ghourab S. Third-trimester transvaginal ultrasonography in placenta previa: does the shape of the lower placental edge predict clinical outcome? Ultrasound Obstet Gynecol 2001;18: 103-8. sourceCould not verify

  Citation 78 is attached to the marginal-sinus part of the sentence. The Methods and Results passages describe placental-edge thickness, vascularity and delivery outcomes, but searches for “marginal sinus” and “sinus” found no passage linking a marginal sinus to caesarean delivery. (LLM, conf=0.76)

  Experimental — accuracy not yet measured
• cites [77] 77. Saitoh M, Ishihara K, Sekiya T, Araki T. Anticipation of uterine bleeding in placenta previa based on vaginal sonographic evaluation. Gynecol Obstet Invest 2002;54:37-42. sourceNot checked — no full text of the source
• cites [78] 78. Taga A, Sato Y, Sakae C, Satake Y, Emoto I, Maruyama S, et al. Planned vaginal delivery versus planned cesarean delivery in cases of low-lying placenta. J Matern Fetal Neonatal Med 2017;30:618-22. sourceNot checked — no full text of the source

The incidence of placenta accreta spectrum increases from 1.7 per 10 000 women overall to 577 per 10 000 in women with both a previous caesarean section and placenta praevia.

“The national case-control study using the UK Obstetric Surveillance System found that the incidence of placenta accreta spectrum increases from 1.7 per 10 000 women overall to 577 per 10 000 in women with both a previous caesarean section and placenta praevia.113”

• cites [113] 113. Fitzpatrick KE, Sellers S, Spark P, Kurinczuk JJ, Brocklehurst P, Knight M. Incidence and risk factors for placenta accreta/increta/ percreta in the UK: a national case-control study. PLoS One 2012;7:e52893. 114. 103. Morlando M, Sarno L, Napolitano R, Capone A, Tessitore G, Maruotti GM, et al. Placenta accreta: incidence and risk factors in an area with a particularly high rate of cesarean section. Acta Obstet Gynecol Scand 2013;92:457-60. sourceSupported

Placenta praevia is another important risk factor for placenta accreta spectrum.

“Placenta praevia is another important risk factor for placenta accreta spectrum (see Appendix II).”

• cites [112] 112. Silver RM, Landon MB, Rouse DJ, Leveno KJ, Spong CY, Thom EA, et al.; National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Maternal morbidity associated with multiple repeat cesarean deliveries. Obstet Gynecol 2006;107:1226-32. sourceNot checked — no full text of the source
• cites [113] 113. Fitzpatrick KE, Sellers S, Spark P, Kurinczuk JJ, Brocklehurst P, Knight M. Incidence and risk factors for placenta accreta/increta/ percreta in the UK: a national case-control study. PLoS One 2012;7:e52893. 114. 103. Morlando M, Sarno L, Napolitano R, Capone A, Tessitore G, Maruotti GM, et al. Placenta accreta: incidence and risk factors in an area with a particularly high rate of cesarean section. Acta Obstet Gynecol Scand 2013;92:457-60. sourceSupported

Overall, the adjusted OR for placenta accreta spectrum after previous uterine surgery is 3.40 (95% CI 1.30-8.91).

“Overall, the aOR for placenta accreta spectrum after previous uterine surgery is 3.40 (95% CI 1.30-8.91).113”

• cites [113] 113. Fitzpatrick KE, Sellers S, Spark P, Kurinczuk JJ, Brocklehurst P, Knight M. Incidence and risk factors for placenta accreta/increta/ percreta in the UK: a national case-control study. PLoS One 2012;7:e52893. 114. 103. Morlando M, Sarno L, Napolitano R, Capone A, Tessitore G, Maruotti GM, et al. Placenta accreta: incidence and risk factors in an area with a particularly high rate of cesarean section. Acta Obstet Gynecol Scand 2013;92:457-60. sourcePartly supported

  The Results > Risk factors section reports an aOR of 3.40 (95% CI 1.30–8.91) for *other* previous uterine surgery, such as myomectomy. The claim omits that qualifier: the paper reports a separate aOR of 14.41 for previous caesarean delivery, so 3.40 is not the estimate for previous uterine surgery overall. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

A caesarean scar pregnancy can be diagnosed using TVS from the second month of pregnancy using specific ultrasound criteria.

“A caesarean scar pregnancy can be diagnosed using TVS from the second month of pregnancy using specific ultrasound criteria.129,130”

• cites [129] 129. Jurkovic D, Knez J, Appiah A, Farahani L, Mavrelos D, Ross JA. Surgical treatment of Caesarean scar pregnancy: efficacy and safety of ultrasound-guided suction curettage. Ultrasound Obstet Gynecol 2016;47:511-7. sourceSupported
• cites [130] 130. Cali G, Forlani F, Timor-Tritsch IE, Palacios-Jaraquemada J, Minneci G, D'Antonio F. Natural history of Caesarean scar pregnancy on prenatal ultrasound: the crossover sign. Ultrasound Obstet Gynecol 2017;50:100-4. sourcePartly supported

  The Methods describe ultrasound images from 6–8 weeks’ gestation and specific criteria used to confirm cesarean scar pregnancy, supporting diagnosis in the second month. The passage does not identify the imaging as transvaginal sonography (TVS), so that part of the claim is not established by our copy. (LLM, conf=0.82)

  Experimental — accuracy not yet measured

Advanced maternal age (35 years or more) in women without a previous caesarean section increases the adjusted OR by 1.30 (95% CI 1.13-1.50) for every 1-year increase in age.

“Advanced maternal age (35 years or more) in women without a previous caesarean section increases the aOR by 1.30 (95% CI 1.13-1.50)for every 1-year increase in age.113”

• cites [113] 113. Fitzpatrick KE, Sellers S, Spark P, Kurinczuk JJ, Brocklehurst P, Knight M. Incidence and risk factors for placenta accreta/increta/ percreta in the UK: a national case-control study. PLoS One 2012;7:e52893. 114. 103. Morlando M, Sarno L, Napolitano R, Capone A, Tessitore G, Maruotti GM, et al. Placenta accreta: incidence and risk factors in an area with a particularly high rate of cesarean section. Acta Obstet Gynecol Scand 2013;92:457-60. sourcePartly supported

  The Results > Risk factors section reports an aOR of 1.30 (95% CI 1.13–1.50) per one-year increase in age among women without a previous caesarean delivery. Table 2 uses 35 years as a cutoff for a separate age comparison, but the paper does not restrict the per-year estimate to women aged 35 or older. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

All epidemiological studies of the last 2 decades have shown a direct association between the increase in caesarean deliveries and the incidence of placenta accreta spectrum in subsequent pregnancies worldwide.

“All epidemiological studies of the last 2 decades have shown a direct association between the increase in caesarean deliveries and the incidence of placenta accreta spectrum (abnormally adherent and invasive placenta) in subsequent pregnancies worldwide.[111][112][113][114][115][116][117][118][119][120][121]”

• cites [111] 111. Wu S, Kocherginsky M, Hibbard JU. Abnormal placentation: twenty-year analysis. Am J Obstet Gynecol 2005;192:1458-61. sourceNot checked — no full text of the source
• cites [112] 112. Silver RM, Landon MB, Rouse DJ, Leveno KJ, Spong CY, Thom EA, et al.; National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Maternal morbidity associated with multiple repeat cesarean deliveries. Obstet Gynecol 2006;107:1226-32. sourceNot checked — no full text of the source
• cites [113] 113. Fitzpatrick KE, Sellers S, Spark P, Kurinczuk JJ, Brocklehurst P, Knight M. Incidence and risk factors for placenta accreta/increta/ percreta in the UK: a national case-control study. PLoS One 2012;7:e52893. 114. 103. Morlando M, Sarno L, Napolitano R, Capone A, Tessitore G, Maruotti GM, et al. Placenta accreta: incidence and risk factors in an area with a particularly high rate of cesarean section. Acta Obstet Gynecol Scand 2013;92:457-60. sourcePartly supported

  The Results (Risk factors; page unavailable) report higher odds of placenta accreta/increta/percreta after a previous caesarean delivery in this UK study. The Discussion (page unavailable) notes similar findings from a few studies outside the UK, but does not establish that all epidemiological studies over two decades found a worldwide association between rising caesarean rates and rising incidence. The study also found no linear association with the number of previous caesarean deliveries. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

Considering the higher frequency of placenta praevia in the accreta group, these results are likely to be influenced by the perinatal complications of placenta praevia.

“Considering the higher frequency of placenta praevia in the accreta group, 143,156 these results are likely to be influenced by the perinatal complications of placenta praevia.”

• cites [143] 143. Jauniaux E, Bhide A. Prenatal ultrasound diagnosis and outcome of placenta previa accreta after cesarean delivery: a systematic review and meta-analysis. Am J Obstet Gynecol 2017;217:27-36. sourceSupported
• cites [156] 156. Vinograd A, Wainstock T, Mazor M, Beer-Weisel R, Klaitman V, Dukler D, et al. Placenta accreta is an independent risk factor for late pre-term birth and perinatal mortality. J Matern Fetal Neonatal Med 2015;28:1381-7. sourceNot checked — no full text of the source

Placenta percreta can be associated with major prenatal complications from early in pregnancy, such as uterine rupture and bladder involvement with associated life-threatening haemorrhage.

“Placenta percreta can be associated with major prenatal complications from early in pregnancy, such as uterine rupture [150][151][152] and bladder involvement with associated life-threatening haemorrhage.[153][154][155]”

• cites [150] 150. Hornemann A, Bohlmann MK, Diedrich K, Kavallaris A, Kehl S, Kelling K, et al. Spontaneous uterine rupture at the 21st week of gestation caused by placenta percreta. Arch Gynecol Obstet 2011;284:875-8. sourceNot checked — no full text of the source
• cites [151] 151. Dew L, Harris S, Yost N, Magee K, dePrisco G. Second trimester placenta percreta presenting as acute abdomen. Proc (Bayl Univ Med Cent) 2015;28:38-40. sourcePartly supported

  The paper’s discussion lists uterine rupture as a complication of placenta percreta and describes potentially life-threatening bleeding in the previable period. Its case description reports bleeding at 21 weeks, but does not report bladder involvement; at delivery, it explicitly notes no invasion of surrounding organs. The bladder-involvement portion is therefore unsupported by this source. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [152] 152. Sun JN, Zhang BL, Yu HY, Zhang Q. Spontaneous uterine rupture due to placenta percreta during pregnancy. Am J Emerg Med 2016;34:1918.e1-3. sourceNot checked — no full text of the source
• cites [153] 153. Abbas F, Talati J, Wasti S, Akram S, Ghaffar S, Qureshi R. Placenta percreta with bladder invasion as a cause of life threatening hemorrhage. J Urol 2000;164:1270-4. sourceNot checked — no full text of the source
• cites [154] 154. Wagaskar VG, Daga SO, Patwardhan SK. Placenta percreta presenting with delayed haematuria. J Clin Diagn Res 2015;9: PD01-2. sourceNot checked — no full text of the source
• cites [155] 155. Brown JV 3rd, Epstein HD, Laflamme LA, Goldstein BH. First- trimester placenta percreta with urinary bladder invasion. Int J Gynaecol Obstet 2016;132:102-3. sourceNot checked — no full text of the source

Ultrasound imaging is highly accurate when performed by a skilled operator with experience in diagnosing placenta accreta spectrum.

“Ultrasound imaging is highly accurate when performed by a skilled operator with experience in diagnosing placenta accreta spectrum.[New 2018]”

• cites [142] 142. D'Antonio F, Iacovella C, Bhide A. Prenatal identification of invasive placentation using ultrasound: systematic review and meta-analysis. Ultrasound Obstet Gynecol 2013;42:509-17. sourceNot checked — no full text of the source
• cites [143] 143. Jauniaux E, Bhide A. Prenatal ultrasound diagnosis and outcome of placenta previa accreta after cesarean delivery: a systematic review and meta-analysis. Am J Obstet Gynecol 2017;217:27-36. sourcePartly supported

  The Conclusions report sensitivity and specificity above 95% when skilled operators diagnose placenta previa accreta in women with prior cesarean delivery who have an anterior low-lying placenta or placenta previa. The claim omits those population and placental-location limits, extending the finding to placenta accreta spectrum generally. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

No ultrasound sign or combination of ultrasound signs has so far been found to be specific to the depth of placenta accreta spectrum to provide an accurate differential diagnosis between adherent and invasive accreta placentation.

“No ultrasound sign or a combination of ultrasound signs have so far been found to be specific to the depth of placenta accreta spectrum to provide an accurate differential diagnosis between adherent and invasive accreta placentation.16”

• cites [16] 16. Jauniaux E, Collins SL, Jurkovic D, Burton GJ. Accreta placentation: a systematic review of prenatal ultrasound imaging and grading of villous invasiveness. Am J Obstet Gynecol 2016;215:712-21. sourceSupported

Determining the depth and lateral extension of placental invasion is helpful for planning the individual care of women diagnosed with placenta accreta spectrum.

“Determining the depth and lateral extension of placental invasion is helpful for planning the individual care of women diagnosed with placenta accreta spectrum.16,17,144”

• cites [16] 16. Jauniaux E, Collins SL, Jurkovic D, Burton GJ. Accreta placentation: a systematic review of prenatal ultrasound imaging and grading of villous invasiveness. Am J Obstet Gynecol 2016;215:712-21. sourcePartly supported

  The Introduction states that determining the depth of placental invasion is essential for planning individual management of women diagnosed with placenta accreta. The Comparison with existing literature section says MRI has been reported useful for assessing lateral extension, but does not say that determining lateral extension helps plan individual care; the Series synthesis of results also notes that no series reported lateral extension. Page numbers are not available in our copy. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [17] 17. Jauniaux E, Collins S, Burton GJ. Placenta accreta spectrum: pathophysiology and evidence-based anatomy for prenatal ultrasound imaging. Am J Obstet Gynecol 2018;218:75-87. sourcePartly supported

  The Introduction (page unavailable) says complication severity varies with the depth of villous invasion and that prenatal diagnosis is essential to PAS management. The Conclusions (page unavailable) say ultrasound signs depend on both depth and lateral extension, but do not say that determining both helps plan an individual woman's care. The paper also cautions in Pathological Correlations that ultrasound signs have not reliably established invasion depth. (LLM, conf=0.83)

  Experimental — accuracy not yet measured
• cites [144] 144. Chantraine F, Nisolle M, Petit P, Schaaps JP, Foidart JM. Individual decisions in placenta increta and percreta: a case series. J Perinat Med 2012;40:265-70. sourceNot checked — no full text of the source

A recent online survey completed by members of the expert panel for the perinatal management of placenta accreta spectrum disorders for FIGO has found wide variation in global practices.

“Similarly, a recent online survey completed by members of the expert panel for the perinatal management of placenta accreta spectrum disorders for the International Federation of Gynecology and Obstetrics (FIGO) has found wide variation in global practices.161”

• cites [161] 161. Cal M, Ayres-de-Campos D, Jauniaux E. International survey of practices used in the diagnosis and management of placenta accreta spectrum disorders. Int J Gynaecol Obstet 2018;140:307-11. sourceSupported

In the absence of risk factors for preterm delivery, it is safe to plan the delivery at 36 weeks of gestation for women with prior caesarean delivery diagnosed prenatally with placenta accreta.

“The data of three recent single institution retrospective cohort studies of women with prior caesarean delivery diagnosed prenatally with placenta accreta have indicated that in the absence of risk factors for preterm delivery, it is safe to plan the delivery at 36 weeks of gestation.”

• cites [168] 168. Seet EL, Kay HH, Wu S, Terplan M. Placenta accreta: depth of invasion and neonatal outcomes. J Matern Fetal Neonatal Med 2012;25:2042-5. sourceNot checked — no full text of the source
• cites [169] 169. Rac MW, Wells CE, Twickler DM, Moschos E, McIntire DD, Dashe JS. Placenta accreta and vaginal bleeding according to gestational age at delivery. Obstet Gynecol 2015;125: 808-13. sourceNot checked — no full text of the source
• cites [170] 170. Perlman NC, Little SE, Thomas A, Cantonwine DE, Carusi DA. Patient selection for later delivery timing with suspected previa- accreta. Acta Obstet Gynecol Scand 2017;96:1021-8. sourcePartly supported

  The Abstract (page unavailable) reports that patients with suspected previa-accreta and no preterm-birth risk factors had a low risk of unscheduled delivery before 36 weeks. The Discussion (page unavailable) supports scheduling selected low-risk patients at 36 weeks or later, but conditions later delivery for those with prior cesarean delivery on experienced care and individualized assessment of invasion risk. Thus, saying it is safe based on the absence of preterm-delivery risk factors alone overstates the paper. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

Emergency delivery still occurs about 20% of the time even in scheduled cases of suspected placenta accreta spectrum.

“which still occurs about 20% of the time even in scheduled cases.164,166”

• cites [164] 164. Publications Committee, Society for Maternal-Fetal Medicine, Belfort MA. Placenta accreta. Am J Obstet Gynecol 2010;203:430-9. sourcePartly supported

  The Antepartum considerations section says emergency delivery may be needed despite a predelivery diagnosis and reports that 4 of 9 patients delivering after 36 weeks required emergency delivery for hemorrhage. It does not give a rate of about 20% for scheduled cases generally. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [166] 166. Belfort MA. Indicated preterm birth for placenta accreta. Semin Perinatol 2011;35:252-6. sourceNot checked — no full text of the source

Women with no risk factors for preterm birth who had reached 34 +0 weeks of gestation with a suspected praevia accreta are at low risk for an unscheduled delivery prior to 36 weeks of gestation.

“The third study of 84 women who had reached 34 +0 weeks of gestation with a suspected praevia accreta found that those with no risk factors for preterm birth are at low risk for an unscheduled delivery prior to 36 weeks of gestation.170”

• cites [170] 170. Perlman NC, Little SE, Thomas A, Cantonwine DE, Carusi DA. Patient selection for later delivery timing with suspected previa- accreta. Acta Obstet Gynecol Scand 2017;96:1021-8. sourceSupported

The main risk associated with the delivery of placenta accreta spectrum is massive haemorrhage and its associated complications, such as coagulopathy, multisystem organ failure and death.

“The main risk associated with the delivery of placenta accreta spectrum is massive haemorrhage and its associated complications, such as coagulopathy, multisystem organ failure and death.”

• cites [171] 171. Green L, Knight M, Seeney FM, Hopkinson C, Collins PW, Collis RE, et al. The epidemiology and outcomes of women with postpartum haemorrhage requiring massive transfusion with eight or more units of red cells: a national cross-sectional study. BJOG 2016;123:2164-70. sourceNot checked — no full text of the source
• cites [172] 172. Brookfield KF, Goodnough LT, Lyell DJ, Butwick AJ. Perioperative and transfusion outcomes in women undergoing cesarean hysterectomy for abnormal placentation. Transfusion 2014;54:1530-6. sourcePartly supported

  The Introduction identifies major hemorrhage and very high blood loss at delivery as risks of abnormal placentation. The Discussion says major obstetric hemorrhage can cause coagulopathy. Our copy does not identify multisystem organ failure or death as complications of delivery with placenta accreta spectrum; its mention of reduced death risk concerns treatment of traumatic hemorrhage in non-obstetric patients. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

In a 2017 systematic review and meta-analysis on the diagnosis and outcome of placenta accreta, an elective or emergency caesarean hysterectomy was performed in 208 out of 232 (89.7%) cases.

“Similarly, in a 2017 systematic review and meta-analysis on the diagnosis and outcome of placenta accreta, an elective or emergency caesarean hysterectomy was performed in 208 out of 232 (89.7%) cases.143”

• cites [143] 143. Jauniaux E, Bhide A. Prenatal ultrasound diagnosis and outcome of placenta previa accreta after cesarean delivery: a systematic review and meta-analysis. Am J Obstet Gynecol 2017;217:27-36. sourceSupported

Women with placenta percreta are more likely to require additional blood products and intensive care admission than women with placenta creta or increta.

“Women with placenta percreta are more likely to require additional blood products and intensive care admission than women with placenta creta or increta.189”

• cites [189] 189. Grace Tan SE, Jobling TW, Wallace EM, McNeilage LJ, Manolitsas T, Hodges RJ. Surgical management of placenta accreta: a 10-year experience. Acta Obstet Gynecol Scand 2013;92:445-50. sourceSupported

The value of prophylactic placement of balloon catheters in the iliac arteries in cases of placenta accreta has been more controversial, mainly because of the higher risks of complications than embolisation, including iliac artery thrombus or rupture, and ischaemic nerve injury.

“The value of prophylactic placement of balloon catheters in the iliac arteries in cases of placenta accreta has been more controversial.This is mainly because of the higher risks of complications than embolisation, including iliac artery thrombus or rupture, and ischaemic nerve injury.[216][217][218][219]”

• cites [216] 216. Bishop S, Butler K, Monaghan S, Chan K, Murphy G, Edozien L. Multiple complications following the use of prophylactic internal iliac artery balloon catheterisation in a patient with placenta percreta. Int J Obstet Anesth 2011;20:70-3. sourceNot checked — no full text of the source
• cites [217] 217. Gagnon J, Boucher L, Kaufman I, Brown R, Moore A. Iliac artery rupture related to balloon insertion for placenta accreta causing maternal hemorrhage and neonatal compromise. Can J Anaesth 2013;60:1212-7. sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured
• cites [218] 218. Teare J, Evans E, Belli A, Wendler R. Sciatic nerve ischaemia after iliac artery occlusion balloon catheter placement for placenta percreta. Int J Obstet Anesth 2014;23:178-81. 219. 107. Matsueda S, Hidaka N, Kondo Y, Fujiwara A, Fukushima K, Kato K. External iliac artery thrombosis after common iliac artery balloon occlusion during cesarean hysterectomy for placenta accreta in cervico-isthmic pregnancy. J Obstet Gynaecol Res 2015;41:1826-30. sourceNot checked — no full text of the source

A second pregnancy within 1 year of a caesarean section is associated with an increased risk of placenta praevia (RR 1.7, 95% CI 0.9-3.1).

“Cohort studies have also reported that a second pregnancy within 1 year of a caesarean section is associated with an increased risk of placenta praevia (RR 1.7, 95% CI 0.9-3.1).26”

• cites [26] 26. Getahun D, Oyelese Y, Salihu HM, Ananth CV. Previous cesarean delivery and risks of placenta previa and placental abruption. Obstet Gynecol 2006;107:771-8. sourceNot checked — no full text of the source

A 2016 meta-analysis of ART singleton pregnancies reported a RR of 3.71 (95% CI 2.67-5.16) for placenta praevia.

“A 2016 meta-analysis of ART singleton pregnancies reported a RR of 3.71 (95% CI 2.67-5.16)for placenta praevia 32”

• cites [32] 32. Qin J, Liu X, Sheng X, Wang H, Gao S. Assisted reproductive technology and the risk of pregnancy-related complications and adverse pregnancy outcomes in singleton pregnancies: a meta- analysis of cohort studies. Fertil Steril 2016;105:73-85.e1-6. sourceNot checked — no full text of the source

Resolution of low-lying placenta before term is less likely to occur in women with a previous caesarean delivery.

“This is less likely to occur in women with a previous caesarean delivery.39”

• cites [39] 39. Cho JY, Lee YH, Moon MH, Lee JH. Difference in migration of placenta according to the location and type of placenta previa. J Clin Ultrasound 2008;36:79-84. sourceNot checked — no full text of the source

A retrospective cohort study of twin live births and stillbirths found no increased risk of placenta praevia in twins.

“A retrospective cohort study of 1 172 405 twin live births and stillbirths in the USA between 1989 and 1998 found no increased risk in twins.28”

• cites [28] 28. Ananth CV, Demissie K, Smulian JC, Vintzileos AM. Placenta praevia in singleton and twin births in the United States, 1989 through 1998: a comparison of risk factor profiles and associated conditions. Am J Obstet Gynecol 2003;188:275-81. sourceNot checked — no full text of the source

The overall odds ratio for placenta praevia after caesarean section is 1.47 (95% CI 1.44-1.51).

“A 2014 meta-analysis confirmed these findings and reported an overall odds ratio (OR) of 1.47 (95% CI 1.44-1.51)for placenta praevia after caesarean section.25”

• cites [25] 25. Klar M, Michels KB. Cesarean section and placental disorders in subsequent pregnancies-a meta-analysis. J Perinat Med 2014;42:571-83. sourceNot checked — no full text of the source

A 2017 meta-analysis found an increased risk of placenta praevia with maternal smoking (OR 1.42, 95% CI 1.30-1.50).

“Furthermore, a 2017 meta-analysis of the impact of maternal smoking on placental position 34 (OR 1.42, 95% CI 1.30-1.50)has found an increased risk of placenta praevia.”

• cites [34] 34. Shobeiri F, Jenabi E. Smoking and placenta previa: a meta-analysis. J Matern Fetal Neonatal Med 2017;30:2985-90. sourceNot checked — no full text of the source

A 2017 meta-analysis confirmed the association between ART and placenta praevia with an OR of 2.67 (95% CI 2.01-3.34).

“that was confirmed by a 2017 metaanalysis (OR 2.67, 95% CI 2.01-3.34).33”

• cites [33] 33. Karami M, Jenabi E, Fereidooni B. The association of placenta previa and associated reproductive techniques: a meta-analysis. J Matern Fetal Neonatal Med 2017;284:47-51. sourceNot checked — no full text of the source

Prior caesarean delivery is associated with a dose-response increase in risk of placenta praevia compared with vaginal delivery, with RR 4.5 for one, 7.4 for two, 6.5 for three, and 44.9 for four or more prior caesarean deliveries.

“In 1997, a meta-analysis of the association of placenta praevia with history of caesarean delivery found a dose-response pattern for the relative risk (RR) of placenta praevia of 4.5 (95% CI 3.6-5.5)for one, 7.4 (95% CI 7.1-7.7)for two, 6.5 (95% CI 3.6-11.6)for three, and 44.9 (95% CI 13.5-149.5)for four or more prior caesarean deliveries compared with vaginal delivery.23”

• cites [23] 23. Ananth CV, Smulian JC, Vintzileos AM. The association of placenta previa with history of cesarean delivery and abortion: a meta-analysis. Am J Obstet Gynecol 1997;177:1071-8. sourceNot checked — no full text of the source

The incidence of placenta praevia increases from 10 in 1000 deliveries with one previous caesarean delivery to 28 in 1000 with three or more caesarean deliveries.

“A systematic review and meta-analysis of 22 studies including over 2 million deliveries indicated that the incidence of placenta praevia increases from 10 in 1000 deliveries with one previous caesarean delivery to 28 in 1000 with three or more caesarean deliveries.24”

• cites [24] 24. Marshall NE, Fu R, Guise JM. Impact of multiple cesarean deliveries on maternal morbidity: a systematic review. Am J Obstet Gynecol 2011;205:262.e1-8. sourceNot checked — no full text of the source

Studies have not demonstrated an increased risk for caesarean section due to haemorrhage when the distance between the internal os and the placental edge is 20 mm or more on TVS.

“Studies have not demonstrated an increased risk for caesarean section due to haemorrhage in these cases.4,5”

• cites [4] 4. Vintzileos AM, Ananth CV, Smulian JC. Using ultrasound in the clinical management of placental implantation abnormalities. Am J Obstet Gynecol 2015;213:S70-7. sourceNot checked — no full text of the source
• cites [5] 5. Silver RM. Abnormal placentation: Placenta previa, vasa previa and placenta accreta. Obstet Gynecol 2015;126:654-68. sourceNot checked — no full text of the source

Among twin pregnancies with placenta praevia diagnosed in the second trimester, the majority of cases resolve by 32 weeks of gestation.

“Among those with placenta praevia diagnosed in the second trimester the majority of cases resolve by 32 weeks of gestation.29,47”

• cites [29] 29. Weis MA, Harper LM, Roehl KA, Odibo AO, Cahill AG. Natural history of placenta previa in twins. Obstet Gynecol 2012;120: 753-8. sourceNot checked — no full text of the source
• cites [47] 47. Kohari KS, Roman AS, Fox NS, Feinberg J, Saltzman DH, Klauser CK, et al. Persistence of placenta previa in twin gestations based on gestational age at sonographic detection. J Ultrasound Med 2012;31:985-9. sourceNot checked — no full text of the source

TVS improves the accuracy of placental localisation particularly when the placenta is posterior or if the TAS is unclear, for example, due to maternal obesity or the presence of large uterine fibroids.

“TVS improves the accuracy of placental localisation particularly when the placenta is posterior or if the TAS is unclear, for example, due to maternal obesity or the presence of large uterine fibroids.5”

• cites [5] 5. Silver RM. Abnormal placentation: Placenta previa, vasa previa and placenta accreta. Obstet Gynecol 2015;126:654-68. sourceNot checked — no full text of the source

Serial TVS cervical length measurements from 26 weeks of gestation indicate that when the length of the cervix decreases rapidly to 35 mm or less there is an increased risk of preterm caesarean section due to massive haemorrhage.

“Serial TVS cervical length measurements from 26 weeks of gestation have indicated that when the length of the cervix decreases rapidly to 35 mm or less there is an increased risk of preterm caesarean section due to massive haemorrhage.60”

• cites [60] 60. Sekiguchi A, Nakai A, Okuda N, Inde Y, Takeshita T. Consecutive cervical length measurements as a predictor of preterm cesarean section in complete placenta previa. J Clin Ultrasound 2015;43:17-22. sourceNot checked — no full text of the source

Combining a cervical length of less than 30 mm and measurement of the lower placental edge thickness of more than 10 mm has a sensitivity of 83.3% and a specificity of 78.4% for predicting outcomes in women with placenta praevia covering the internal os.

“Similarly, a prospective cohort study of 54 women with placenta praevia covering the internal os has shown that combining a cervical length of less than 30 mm and measurement of the lower placental edge thickness of more than 10 mm has a sensitivity of 83.3% and a specificity of 78.4%.58”

• cites [58] 58. Zaitoun MM, El Behery MM, Abd El Hameed AA, Soliman BS. Does cervical length and the lower placental edge thickness measurement correlates with clinical outcome in cases of complete placenta previa? Arch Gynecol Obstet 2011;284:867-73. sourceNot checked — no full text of the source

There is no evidence that neonates born after pregnancies with placenta praevia are more likely to be small for gestational age when compared to non-praevia controls.

“There is no evidence, however, that neonates born after pregnancies with placenta praevia are more likely to be small for gestational age when compared to non-praevia controls.65”

• cites [65] 65. Nørgaard LN, Pinborg A, Lidegaard Ø, Bergholt T. A Danish national cohort study on neonatal outcome in singleton pregnancies with placenta previa. Acta Obstet Gynecol Scand 2012;91:546-51. sourceNot checked — no full text of the source

Compared with neonates born at 38 weeks, those delivered at 35, 36 and 37 weeks have no greater odds of meconium passage, fetal distress, fetal anaemia, neonatal seizures, increased ventilator needs or infant death at 1 year.

“Compared with neonates born at 38 weeks of gestation, those delivered at 35, 36 and 37 weeks of gestation have no greater odds of meconium passage, fetal distress, fetal anaemia, neonatal seizures, increased ventilator needs or infant death at 1 year.”

• cites [74] 74. Balayla J, Wo BL, B edard MJ. A late-preterm, early-term stratified analysis of neonatal outcomes by gestational age in placenta previa: defining the optimal timing for delivery. J Matern Fetal Neonatal Med 2015;28:1756-61. sourceNot checked — no full text of the source

A systematic review identified two retrospective studies (total n = 217) and one RCT (n = 60) on prolonged (48 hours or more) use of tocolytics in women with symptomatic preterm placenta praevia.

“A systematic review to determine if the prolonged (48 hours or more) use of tocolytics in women with symptomatic preterm placenta praevia improves perinatal outcome identified two retrospective studies (total, n = 217) and one RCT (n = 60).69”

• cites [69] 69. Bose DA, Assel BG, Hill JB, Chauhan SP. Maintenance tocolytics for preterm symptomatic placenta previa: a review. Am J Perinatol 2011;28:45-50. sourceNot checked — no full text of the source

If the placenta extends beyond the internal os on TVS during the second trimester, it is likely to be confirmed as placenta praevia at 32 weeks of gestation.

“By contrast, if the placenta extends beyond the internal os on TVS during the second trimester, it is likely to be confirmed as placenta praevia at 32 weeks of gestation.[48][49][50]”

• cites [48] 48. Sherman SJ, Carlson DE, Platt LD, Medearis AL. Transvaginal ultrasound: does it help in the diagnosis of placenta previa? Ultrasound Obstet Gynecol 1992;2:256-60. sourceNot checked — no full text of the source
• cites [49] 49. Mustaf a SA, Brizot ML, Carvalho MH, Watanabe L, Kahhale S, Zugaib M. Transvaginal ultrasonography in predicting placenta previa at delivery: a longitudinal study. Ultrasound Obstet Gynecol 2002;20:356-9. sourceNot checked — no full text of the source
• cites [50] 50. Becker RH, Vonk R, Mende BC, Ragosch V, Entezami M. The relevance of placental location at 20-23 gestational weeks for prediction of placenta previa at delivery: evaluation of 8650 cases. Ultrasound Obstet Gynecol 2001;17:496-501. sourceNot checked — no full text of the source

Compared with neonates born at 38 weeks, those delivered at 35 and 36 weeks have greater odds of 5-minute Apgar scores less than 7 (aOR 3.33, 95% CI 1.71-6.47 and aOR 2.17, 1.11-4.22, respectively).

“However, aOR odds of 5-minute Apgar scores of less than 7 are greater at 35 and 36 weeks of gestation (aOR 3.33, 95% CI 1.71-6.47;and aOR 2.17, 1.11-4.22,respectively)”

• cites [74] 74. Balayla J, Wo BL, B edard MJ. A late-preterm, early-term stratified analysis of neonatal outcomes by gestational age in placenta previa: defining the optimal timing for delivery. J Matern Fetal Neonatal Med 2015;28:1756-61. sourceNot checked — no full text of the source

In the RCT, continued tocolytics prolonged pregnancy for more than 7 days (OR 3.10, 95% CI 1.38-6.96).

“The results of the RCT showed that pregnancy can be prolonged for more than 7 days with continued tocolytics (OR 3.10, 95% CI 1.38-6.96).”

• cites [69] 69. Bose DA, Assel BG, Hill JB, Chauhan SP. Maintenance tocolytics for preterm symptomatic placenta previa: a review. Am J Perinatol 2011;28:45-50. sourceNot checked — no full text of the source

When RCT data were combined with retrospective studies, the effect on perinatal outcome did not reach significance (OR 1.19, 95% CI 0.63-2.28).

“When combined with the data of retrospective studies, the results did not reach significance (OR 1.19, 95% CI 0.63-2.28).”

• cites [69] 69. Bose DA, Assel BG, Hill JB, Chauhan SP. Maintenance tocolytics for preterm symptomatic placenta previa: a review. Am J Perinatol 2011;28:45-50. sourceNot checked — no full text of the source

Numerous factors influence the chances of low-lying placenta or placenta praevia persisting until delivery, such as prior caesarean section, the distance between the placental edge and the internal os, and the thickness of the placental edge.

“Numerous factors influence the chances of low-lying placenta or placenta praevia persisting until delivery, such as prior caesarean section, 43 the distance between the placental edge and the internal os, and the thickness of the placental edge.4”

• cites [43] 43. Lal AK, Nyholm J, Wax J, Rose CH, Watson WJ. Resolution of complete placenta previa: does prior cesarean delivery matter? J Ultrasound Med 2012;31:577-80. sourceNot checked — no full text of the source
• cites [4] 4. Vintzileos AM, Ananth CV, Smulian JC. Using ultrasound in the clinical management of placental implantation abnormalities. Am J Obstet Gynecol 2015;213:S70-7. sourceNot checked — no full text of the source

TVS will reclassify 26-60% of placentas diagnosed as low lying at the routine fetal anomaly scan.

“TVS will reclassify 26-60% of placentas diagnosed as low lying at the routine fetal anomaly scan.[52][53][54]”

• cites [52] 52. Taipale P, Hiilesmaa V, Yl€ ostalo P. Transvaginal ultrasonography at 18-23 weeks in predicting placenta praevia at delivery. Ultrasound Obstet Gynecol 1998;12:422-5. sourceNot checked — no full text of the source
• cites [53] 53. Lauria MR, Smith RS, Treadwell MC, Comstock CH, Kirk JS, Lee W, et al. The use of second-trimester transvaginal sonography to predict placenta previa. Ultrasound Obstet Gynecol 1996;8:337-40. sourceNot checked — no full text of the source
• cites [54] 54. Smith RS, Lauria MR, Comstock CH, Treadwell MC, Kirk JS, Lee W, et al. Transvaginal ultrasonography for all placentas that appear to be low-lying or over the internal cervical os. Ultrasound Obstet Gynecol 1997;9:22-4. sourceNot checked — no full text of the source

A decision analytic model indicated that corticosteroids administration at 35+5 weeks of gestation followed by planned delivery at 36 weeks of gestation optimises maternal and neonatal outcomes for women with placenta praevia.

“A decision analytic model designed to compare total maternal and neonatal quality-adjusted life years for delivery of women with placenta praevia at 34 +0 to 36 +6 weeks of gestation indicated that corticosteroids administration at 35 +5 weeks of gestation followed by planned delivery at 36 weeks of gestation optimises maternal and neonatal outcomes.69”

• cites [69] 69. Bose DA, Assel BG, Hill JB, Chauhan SP. Maintenance tocolytics for preterm symptomatic placenta previa: a review. Am J Perinatol 2011;28:45-50. sourceNot checked — no full text of the source

TVS has a high accuracy in predicting placenta praevia in women suspected of having a low-lying placenta on TAS in the second and early third trimester, with a positive predictive value of 93.3%, negative predictive value of 97.6%, false-negative rate of 2.33%, sensitivity of 87.5% and specificity of 98.8%.

“Overall, TVS has a high accuracy (positive predictive value of 93.3%, negative predictive value of 97.6% and false-negative rate of 2.33%) in predicting placenta praevia in women suspected of having a low-lying placenta on TAS in the second and early third trimester, with a sensitivity of 87.5% and a specificity of 98.8%.55”

• cites [55] 55. Leerentveld RA, Gilberts EC, Arnold MJ, Wladimiroff JW. Accuracy and safety of transvaginal sonographic placental localization. Obstet Gynecol 1990;76:759-62. sourceNot checked — no full text of the source

In twin pregnancies, the likelihood of persistence of placenta praevia is dependent on the gestational age at sonographic detection.

“In twin pregnancies, the likelihood of persistence of placenta praevia is also dependent on the gestational age at sonographic detection.”

• cites [29] 29. Weis MA, Harper LM, Roehl KA, Odibo AO, Cahill AG. Natural history of placenta previa in twins. Obstet Gynecol 2012;120: 753-8. sourceNot checked — no full text of the source
• cites [47] 47. Kohari KS, Roman AS, Fox NS, Feinberg J, Saltzman DH, Klauser CK, et al. Persistence of placenta previa in twin gestations based on gestational age at sonographic detection. J Ultrasound Med 2012;31:985-9. sourceNot checked — no full text of the source

Compared with women with a long cervical length, women with a short cervical length (less than 25 mm) have a RR of 7.2 (95% CI 2.3-22.3) for massive haemorrhage during caesarean section for placenta praevia.

“Compared with women with a long cervical length, women with a short cervical length (less than 25 mm) have a RR of 7.2 (95% CI 2.3-22.3)for massive haemorrhage during caesarean section for placenta praevia.59”

• cites [59] 59. Mimura T, Hasegawa J, Nakamura M, Matsuoka R, Ichizuka K, Sekizawa A, et al. Correlation between the cervical length and the amount of bleeding during cesarean section in placenta previa. J Obstet Gynaecol Res 2011;37:830-5. sourceNot checked — no full text of the source

Intraoperative interventional radiological techniques, including transarterial embolisation and temporary balloon occlusion of internal iliac arteries, have been successfully used to prevent and control haemorrhage in placenta praevia.

“Intraoperative interventional radiological techniques, including transarterial embolisation 106 and temporary balloon occlusion 107 of the internal iliac arteries, have also been successfully used to prevent and control haemorrhage in placenta praevia”

• cites [106] 106. Inoue S, Masuyama H, Hiramatsu Y; Multi-Institutional Study Group of Transarterial Embolization for Massive Obstetric Haemorrhage in Chugoku & Shikoku Area Society of Obstetrics and Gynecology. Efficacy of transarterial embolisation in the management of post-partum haemorrhage and its impact on subsequent pregnancies. Aust N Z J Obstet Gynaecol 2014;54: 541-5. sourceNot checked — no full text of the source
• cites [107] 107. Broekman EA, Versteeg H, Vos LD, Dijksterhuis MG, Papatsonis DN. Temporary balloon occlusion of the internal iliac arteries to prevent massive hemorrhage during cesarean delivery among patients with placenta previa. Int J Gynaecol Obstet 2015;128:118-21. sourceNot checked — no full text of the source

No definite cases of amniotic fluid embolism have been reported so far with cell salvage.

“No definite cases of amniotic fluid embolism have been reported so far”

• cites [93] 93. Goucher H, Wong CA, Patel SK, Toledo P. Cell salvage in obstetrics. Anesth Analg 2015;121:465-8. sourceNot checked — no full text of the source
• cites [94] 94. Morikawa M, Kuramoto A, Nakayama M, Oguchi H, Hasegawa M, Funakoshi T, et al. Intraoperative red cell salvage during obstetric surgery in 50 Japanese women. Int J Gynaecol Obstet 2015;128:256-9. sourceNot checked — no full text of the source

Women having caesarean section for placenta praevia are at increased risk of blood loss of more than 1000 ml compared with women having caesarean section for other indications (RR 3.97, 95% CI 3.24-4.85).

“Women having a caesarean section for placenta praevia are at increased risk of blood loss of more than 1000 ml compared with women having a caesarean section for other indications (RR 3.97, 95% CI 3.24-4.85).84”

• cites [84] 84. Thomas J, Paranjothy S, editors. The National Sentinel Caesarean Section Audit Report. London: RCOG Press; 2001.Not checked — no full text of the source

A retrospective cohort study found that avoiding incision of the anterior placenta praevia after 24 weeks of gestation reduces the need for maternal blood transfusion during or after caesarean delivery.

“A retrospective cohort study found that avoiding incision of the anterior placenta praevia after 24 weeks of gestation reduces the need for maternal blood transfusion during or after caesarean delivery.95”

• cites [95] 95. Verspyck E, Douysset X, Roman H, Marret S, Marpeau L. Transecting versus avoiding incision of the anterior placenta previa during cesarean delivery. Int J Gynaecol Obstet 2015;128:44-7. sourceNot checked — no full text of the source

The risk of massive haemorrhage together with the possibility of needing a blood transfusion is approximately 12 times more likely in caesarean section for placenta praevia than in caesarean delivery for other indications.

“The risk of massive haemorrhage together with the possibility of needing a blood transfusion has been estimated to be approximately 12 times more likely in caesarean section for placenta praevia than in caesarean delivery for other indications.87,88”

• cites [87] 87. Mavrides E, Allard S, Chandraharan E, Collins P, Green L, Hunt BJ, et al. on behalf of the Royal College of Obstetricians and Gynaecologists. Prevention and management of postpartum haemorrhage. BJOG 2016;124:e106-49.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [88] 88. Royal College of Obstetricians and Gynaecologists. Blood Transfusions in Obstetrics. Green-top Guideline No. 47. London: RCOG; 2015.Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Placenta praevia is often associated with additional complications, including fetal malpresentation (transverse or breech presentation) requiring complex intraoperative manoeuvres to deliver the baby.

“Placenta praevia is often associated with additional complications, including fetal malpresentation (transverse or breech presentation) requiring complex intraoperative manoeuvres to deliver the baby.90”

• cites [90] 90. Pelosi MA, Apuzzio J, Fricchione D, Gowda VV. The "intra- abdominal version technique" for delivery of transverse lie by low- segment caesarean section. Am J Obstet Gynecol 1979;135:1009-11. sourceNot checked — no full text of the source

Maternal complications at caesarean section increase when the primary surgeon is a trainee rather than an experienced surgeon.

“Maternal complications at caesarean section increase when the primary surgeon is a trainee rather than an experienced surgeon.89”

• cites [89] 89. Madsen K, Grønbeck L, Rifbjerg Larsen C, Østergaard J, Bergholt T, Langhoff-Roos J, et al. Educational strategies in performing cesarean section. Acta Obstet Gynecol Scand 2013;92:256-63. sourceNot checked — no full text of the source

Follow-up studies suggest that arterial embolisation for control of PPH does not impair subsequent menstruation and fertility.

“Follow-up studies of women who have undergone arterial embolisation for control of PPH suggest that the intervention does not impair subsequent menstruation and fertility.”

• cites [108] 108. Sentilhes L, Gromez A, Clavier E, Resch B, Verspyck E, Marpeau L. Fertility and pregnancy following pelvic arterial embolisation for postpartum haemorrhage. BJOG 2010;117:84-93. sourceNot checked — no full text of the source
• cites [109] 109. Doumouchtsis SK, Nikolopoulos K, Talaulikar V, Krishna A, Arulkumaran S. Menstrual and fertility outcomes following the surgical management of postpartum haemorrhage: a systematic review. BJOG 2014;121:382-8. sourceNot checked — no full text of the source
• cites [110] 110. Soro MP, Denys A, de Rham M, Baud D. Short and long term adverse outcomes after arterial embolisation for the treatment of postpartum haemorrhage: a systematic review. Eur Radiol 2017;27:749-62. sourceNot checked — no full text of the source

The risks of cell salvage in the obstetric population parallel those in the nonpregnant population.

“the risks of cell salvage in the obstetric population parallel those in the nonpregnant population.93,94”

• cites [93] 93. Goucher H, Wong CA, Patel SK, Toledo P. Cell salvage in obstetrics. Anesth Analg 2015;121:465-8. sourceNot checked — no full text of the source
• cites [94] 94. Morikawa M, Kuramoto A, Nakayama M, Oguchi H, Hasegawa M, Funakoshi T, et al. Intraoperative red cell salvage during obstetric surgery in 50 Japanese women. Int J Gynaecol Obstet 2015;128:256-9. sourceNot checked — no full text of the source

An RCT of regional versus general anaesthesia for placenta praevia, including women with placenta accreta, indicated that blood transfusion requirements (although not estimated blood loss) are greater in the general anaesthetic group.

“An RCT of regional versus general anaesthesia for placenta praevia, including women with placenta accreta, has indicated that blood transfusion requirements (although not estimated blood loss) are greater in the general anaesthetic group.91”

• cites [91] 91. Hong JY, Jee YS, Yoon HJ, Kim SM. Comparison of general and epidural anesthesia in elective cesarean section for placenta pevia totalis: maternal hemodynamics, blood loss and neonatal outcome. Int J Obstet Anesth 2003;12:12-6. sourceNot checked — no full text of the source

In cases of anterior placenta praevia, cutting through the placenta is often associated with increased maternal bleeding.

“In cases of anterior placenta praevia, cutting through the placenta is often associated with increased maternal bleeding.”

• cites [95] 95. Verspyck E, Douysset X, Roman H, Marret S, Marpeau L. Transecting versus avoiding incision of the anterior placenta previa during cesarean delivery. Int J Gynaecol Obstet 2015;128:44-7. sourceNot checked — no full text of the source

The risk of placenta accreta spectrum rises as the number of prior caesarean sections increases.

“This risk rises as the number of prior caesarean sections increases.”

• cites [111] 111. Wu S, Kocherginsky M, Hibbard JU. Abnormal placentation: twenty-year analysis. Am J Obstet Gynecol 2005;192:1458-61. sourceNot checked — no full text of the source
• cites [120] 120. Thurn L, Lindqvist PG, Jakobsson M, Colmorn LB, Klungsoyr K, Bjarnad ottir RI, et al. Abnormally invasive placenta-prevalence, risk factors and antenatal suspicion: results from a large population-based pregnancy cohort study in the Nordic countries. BJOG 2016;123:1348-55. sourceNot checked — no full text of the source

Women with anterior placenta are at increased risk of blood loss.

“Women with anterior placenta are at increased risk of blood loss.85”

• cites [85] 85. Baba Y, Matsubara S, Ohkuchi A, Usui R, Kuwata T, Suzuki H, et al. Anterior placentation as a risk factor for massive hemorrhage during cesarean section in patients with placenta previa. J Obstet Gynaecol Res 2014;40:1243-8. sourceNot checked — no full text of the source

In a series from specialist centres, approximately one-third of cases of placenta accreta were not diagnosed during pregnancy.

“In a series from specialist centres, approximately one-third of cases of placenta accreta were not diagnosed during pregnancy.137”

• cites [137] 137. Bowman ZS, Eller AG, Kennedy AM, Richards DS, Winter TC 3rd, Woodward PJ, et al. Accuracy of ultrasound for the prediction of placenta accreta. Am J Obstet Gynecol 2014;211:177.e1-7. sourceNot checked — no full text of the source

Maternal complications in placenta accreta spectrum are primarily the result of massive haemorrhage.

“Maternal complications in placenta accreta spectrum are primarily the result of massive haemorrhage.5”

• cites [5] 5. Silver RM. Abnormal placentation: Placenta previa, vasa previa and placenta accreta. Obstet Gynecol 2015;126:654-68. sourceNot checked — no full text of the source

Other surgical trauma to the integrity of the uterine endometrium and/or superficial myometrium, such as following uterine curettage, manual removal of the placenta, postpartum endometritis or myomectomy, has been associated with accreta placentation in subsequent pregnancies.

“Other surgical trauma to the integrity of the uterine endometrium and/or superficial myometrium, such as those following uterine curettage, manual removal of the placenta, postpartum endometritis or myomectomy, has been associated with accreta placentation in subsequent pregnancies.1,12,13”

• cites [1] 1. Jauniaux E, Jurkovic D. Placenta accreta: pathogenesis of a 20th century iatrogenic uterine disease. Placenta 2012;33:244-51. sourceNot checked — no full text of the source
• cites [12] 12. Luke RK, Sharpe JW, Greene RR. Placenta accreta: the adherent or invasive placenta. Am J Obstet Gynecol 1966;95:660-8. sourceNot checked — no full text of the source
• cites [13] 13. Fox H, Sebire NJ, editors. Pathology of the Placenta. 3rd edition. Philadelphia: Saunders-Elsevier; 2007. sourceNot checked — no full text of the source

The development of placenta accreta spectrum has also been reported in women with no surgical history but presenting with a uterine pathology, such as bicornuate uterus, adenomyosis, submucous fibroids and myotonic dystrophy.

“The development of placenta accreta spectrum has also been reported in women with no surgical history but presenting with a uterine pathology, such as bicornuate uterus, adenomyosis, submucous fibroids and myotonic dystrophy.”

• cites [1] 1. Jauniaux E, Jurkovic D. Placenta accreta: pathogenesis of a 20th century iatrogenic uterine disease. Placenta 2012;33:244-51. sourceNot checked — no full text of the source
• cites [12] 12. Luke RK, Sharpe JW, Greene RR. Placenta accreta: the adherent or invasive placenta. Am J Obstet Gynecol 1966;95:660-8. sourceNot checked — no full text of the source
• cites [13] 13. Fox H, Sebire NJ, editors. Pathology of the Placenta. 3rd edition. Philadelphia: Saunders-Elsevier; 2007. sourceNot checked — no full text of the source

For women presenting with placenta praevia and prior caesarean section, the risk of accreta placentation is 3%, 11%, 40%, 61% and 67% for one, two, three, four, and five or more caesarean deliveries, respectively.

“A large multicentre US cohort study noted that for women presenting with placenta praevia and prior caesarean section the risk of accreta placentation is 3%, 11%, 40%, 61% and 67% for one, two, three, four, and five or more caesarean deliveries, respectively.112”

• cites [112] 112. Silver RM, Landon MB, Rouse DJ, Leveno KJ, Spong CY, Thom EA, et al.; National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Maternal morbidity associated with multiple repeat cesarean deliveries. Obstet Gynecol 2006;107:1226-32. sourceNot checked — no full text of the source

The 2016 Nordic Obstetric Surveillance Study found that the risk of invasive placentation increases seven-fold after one prior caesarean section.

“The 2016 Nordic Obstetric Surveillance Study found that the risk of invasive placentation increases seven-fold after one prior caesarean section.117”

• cites [117] 117. Eshkoli T, Weintraub AY, Sergienko R, Sheiner E. Placenta accreta: risk factors, perinatal outcomes, and consequences for subsequent births. Am J Obstet Gynecol 2013;208:219.e1-7. sourceNot checked — no full text of the source

A meta-analysis of five cohorts and 11 case-control studies reported a summary OR of 1.96 (95% CI 1.41-2.74) for placenta accreta spectrum after a caesarean section.

“A meta-analysis of five cohorts and 11 case-control studies reported a summary OR of 1.96 (95% CI 1.41-2.74)for placenta accreta spectrum after a caesarean section.24”

• cites [24] 24. Marshall NE, Fu R, Guise JM. Impact of multiple cesarean deliveries on maternal morbidity: a systematic review. Am J Obstet Gynecol 2011;205:262.e1-8. sourceNot checked — no full text of the source

Placenta accreta spectrum is not exclusively a consequence of caesarean delivery.

“Placenta accreta spectrum is not exclusively a consequence of caesarean delivery.”

• cites [1] 1. Jauniaux E, Jurkovic D. Placenta accreta: pathogenesis of a 20th century iatrogenic uterine disease. Placenta 2012;33:244-51. sourceNot checked — no full text of the source
• cites [12] 12. Luke RK, Sharpe JW, Greene RR. Placenta accreta: the adherent or invasive placenta. Am J Obstet Gynecol 1966;95:660-8. sourceNot checked — no full text of the source
• cites [13] 13. Fox H, Sebire NJ, editors. Pathology of the Placenta. 3rd edition. Philadelphia: Saunders-Elsevier; 2007. sourceNot checked — no full text of the source

Antenatal diagnosis of placenta accreta spectrum reduces maternal peripartum haemorrhage and morbidity.

“Antenatal diagnosis of placenta accreta spectrum reduces maternal peripartum haemorrhage and morbidity.20,[132][133][134][135]”

• cites [20] 20. Bowman ZS, Manuck TA, Eller AG, Simons M, Silver RM. Risk factors for unscheduled delivery in patients with placenta accreta. Am J Obstet Gynecol 2014;210:241.e1-6. sourceNot checked — no full text of the source
• cites [132] 132. Tikkanen M, Paavonen J, Loukovaara M, Stefanovic V. Antenatal diagnosis of placenta accreta leads to reduced blood loss. Acta Obstet Gynecol Scand 2011;90:1140-6. sourceNot checked — no full text of the source
• cites [133] 133. Chantraine F, Braun T, Gonser M, Henrich W, Tutschek B. Prenatal diagnosis of abnormally invasive placenta reduces maternal peripartum hemorrhage and morbidity. Acta Obstet Gynecol Scand 2013;92:439-44. sourceNot checked — no full text of the source
• cites [134] 134. Hall T, Wax JR, Lucas FL, Cartin A, Jones M, Pinette MG. Prenatal sonographic diagnosis of placenta accreta: Impact on maternal and neonatal outcomes. J Clin Ultrasound 2014;42:449-55. sourceNot checked — no full text of the source
• cites [135] 135. Silver RM, Fox KA, Barton JR, Abuhamad AZ, Simhan H, Huls CK, et al. Center of excellence for placenta accreta. Am J Obstet Gynecol 2015;212:561-8. sourceNot checked — no full text of the source

A systematic review reported an increase in incidence of accreta placentation from 3.3-4.0% in women with placenta praevia and no previous caesarean delivery to 50-67% in women with three or more caesarean deliveries.

“A systematic review reported an increase in the incidence of accreta placentation from 3.3-4.0%in women with placenta praevia and no previous caesarean delivery, to 50-67% in women with three or more caesarean deliveries.25”

• cites [25] 25. Klar M, Michels KB. Cesarean section and placental disorders in subsequent pregnancies-a meta-analysis. J Perinat Med 2014;42:571-83. sourceNot checked — no full text of the source

Women admitted at 34 weeks of gestation and delivered between 34 and 35 weeks of gestation by a specialist multidisciplinary team have a significantly lower emergency surgery rate than those not cared for by such a team (23% versus 64%; P = 0.001) despite a similar median gestational age at delivery.

“Women admitted at 34 weeks of gestation and delivered between 34 and 35 weeks of gestation by a specialist multidisciplinary team have a significantly lower emergency surgery rate than those not cared for by such a team (23% versus 64%; P = 0.001) despite a similar median gestational age at delivery [34 (16-39) weeks versus 34 (19-40) weeks; P = 0.50, respectively].21”

• cites [21] 21. Shamshirsaz AA, Fox KA, Salmanian B, Diaz-Arrastia CR, Lee W, Baker BW, et al. Maternal morbidity in patients with morbidly adherent placenta treated with and without a standardized multidisciplinary approach. Am J Obstet Gynecol 2015;212:218.e1-9 sourceNot checked — no full text of the source

A retrospective cohort study of 77 women with suspected placenta accreta found that women who delivered prior to a planned delivery date were significantly more likely to have had vaginal bleeding and uterine activity when compared with women who had a scheduled delivery.

“A retrospective cohort study of 77 women with suspected placenta accreta found that women who delivered prior to a planned delivery date were significantly more likely to have had vaginal bleeding and uterine activity when compared with women who had a scheduled delivery.20”

• cites [20] 20. Bowman ZS, Manuck TA, Eller AG, Simons M, Silver RM. Risk factors for unscheduled delivery in patients with placenta accreta. Am J Obstet Gynecol 2014;210:241.e1-6. sourceNot checked — no full text of the source

Surveys of healthcare providers in the US and Canada have highlighted widely varied approaches to virtually every aspect of care for placenta accreta spectrum.

“Surveys of healthcare providers in the US and Canada have highlighted widely varied approaches to virtually every aspect of care for placenta accreta spectrum.[157][158][159][160]”

• cites [157] 157. Mehrabadi A, Hutcheon JA, Liu S, Bartholomew S, Kramer MS, Liston RM, et al.; Maternal Health Study Group of Canadian Perinatal Surveillance System (Public Health Agency of Canada). Contribution of placenta accreta to the incidence of postpartum hemorrhage and severe postpartum hemorrhage. Obstet Gynecol 2015;125:814-21. sourceNot checked — no full text of the source
• cites [158] 158. Jolley JA, Nageotte MP, Wing DA, Shrivastava VK. Management of placenta accreta: a survey of Maternal-Fetal Medicine practitioners. J Matern Fetal Neonatal Med 2012;25:756-60. sourceNot checked — no full text of the source
• cites [159] 159. Esakoff TF, Handler SJ, Granados JM, Caughey AB. PAMUS: placenta accreta management across the United States. J Matern Fetal Neonatal Med 2012;25:761-5. sourceNot checked — no full text of the source
• cites [160] 160. Wright JD, Silver RM, Bonanno C, Gaddipati S, Lu YS, Simpson LL, et al. Practice patterns and knowledge of obstetricians and gynecologists regarding placenta accreta. J Matern Fetal Neonatal Med 2013;26:1602-9. sourceNot checked — no full text of the source

Abnormal vasculature on CDI had the best predictive accuracy with a sensitivity of 90.74% (95% CI 85.2-94.7), specificity of 87.68% (95% CI 84.6-90.4) and diagnostic OR of 69.02 (95% CI 22.8-208.9).

“Abnormal vasculature on CDI had the best predictive accuracy with a sensitivity of 90.74% (95% CI 85.2-94.7),specificity of 87.68% (95% CI 84.6-90.4) and diagnostic OR of 69.02 (95% CI 22.8-208.9).142”

• cites [142] 142. D'Antonio F, Iacovella C, Bhide A. Prenatal identification of invasive placentation using ultrasound: systematic review and meta-analysis. Ultrasound Obstet Gynecol 2013;42:509-17. sourceNot checked — no full text of the source

Among different ultrasound signs, abnormality of the uterus-bladder interface had the best specificity of 99.75% (95% CI 99.5-99.9) for prediction of placenta accreta.

“Among the different ultrasound signs, abnormality of the uterus-bladder interface had the best specificity of 99.75% (95% CI 99.5-99.9)for the prediction of placenta accreta.”

• cites [142] 142. D'Antonio F, Iacovella C, Bhide A. Prenatal identification of invasive placentation using ultrasound: systematic review and meta-analysis. Ultrasound Obstet Gynecol 2013;42:509-17. sourceNot checked — no full text of the source

There are currently no RCTs or well-controlled observational studies to guide best practice in delivery timing of placenta accreta spectrum.

“There are currently no RCTs or well-controlled observational studies to guide best practice in delivery timing of placenta accreta spectrum.”

The latter review also found that MRI has high predictive accuracy in assessing both the depth and topography of placental invasion.

“The latter review also found that MRI has high predictive accuracy in assessing both the depth and topography of placental invasion.”

• cites [148] 148. D'Antonio F, Iacovella C, Palacios-Jaraquemada J, Bruno CH, Manzoli L, Bhide A. Prenatal identification of invasive placentation using magnetic resonance imaging: systematic review and meta-analysis. Ultrasound Obstet Gynecol 2014;44:8-16. sourceNot checked — no full text of the source

Two systematic reviews and meta-analyses found that the diagnostic value of ultrasound imaging and MRI in detecting placenta accreta spectrum is similar.

“Two systematic reviews and meta-analyses have found that the diagnostic value of ultrasound imaging and MRI in detecting placenta accreta spectrum is similar.”

• cites [147] 147. Meng X, Xie L, Song W. Comparing the diagnostic value of ultrasound and magnetic resonance imaging for placenta accreta: a systematic review and meta-analysis. Ultrasound Med Biol 2013;39:1958-65. sourceNot checked — no full text of the source
• cites [148] 148. D'Antonio F, Iacovella C, Palacios-Jaraquemada J, Bruno CH, Manzoli L, Bhide A. Prenatal identification of invasive placentation using magnetic resonance imaging: systematic review and meta-analysis. Ultrasound Obstet Gynecol 2014;44:8-16. sourceNot checked — no full text of the source

Maternal outcomes are improved over time with increasing experience within a well-established multidisciplinary team performing two to three cases per month.

“In addition, maternal outcomes are improved over time with increasing experience within a well-established multidisciplinary team performing two to three cases per month.22”

• cites [22] 22. Shamshirsaz AA, Fox KA, Erfani H, Clark SL, Salmanian B, Baker BW, et al. Multidisciplinary team learning in the management of the morbidly adherent placenta: outcome improvements over time. Am J Obstet Gynecol 2017;216:612.e1-e5. sourceNot checked — no full text of the source

The diagnostic value of MRI and ultrasound imaging in detecting placenta accreta spectrum is similar when performed by experts.

“Clinicians should be aware that the diagnostic value of MRI and ultrasound imaging in detecting placenta accreta spectrum is similar when performed by experts.[New 2018]”

• cites [147] 147. Meng X, Xie L, Song W. Comparing the diagnostic value of ultrasound and magnetic resonance imaging for placenta accreta: a systematic review and meta-analysis. Ultrasound Med Biol 2013;39:1958-65. sourceNot checked — no full text of the source
• cites [148] 148. D'Antonio F, Iacovella C, Palacios-Jaraquemada J, Bruno CH, Manzoli L, Bhide A. Prenatal identification of invasive placentation using magnetic resonance imaging: systematic review and meta-analysis. Ultrasound Obstet Gynecol 2014;44:8-16. sourceNot checked — no full text of the source

There is limited evidence to support uterus preserving surgery in placenta percreta.

“There is limited evidence to support uterus preserving surgery in placenta percreta and women should be informed of the high risk of peripartum and secondary complications, including the need for secondary hysterectomy.”

The optimal management of placenta accreta spectrum remains undefined due to a lack of RCTs or well-controlled observational studies.

“Due to a lack of RCTs or well-controlled observational studies, the optimal management of placenta accreta spectrum remains undefined”

There are no RCTs comparing different surgical approaches for placenta accreta spectrum suspected antenatally.

“There are no RCTs comparing different surgical approaches for placenta accreta spectrum suspected antenatally.”

Since the publication of the last version of this guideline there have been several cohort studies describing the use of interventional radiology in assisting surgical and conservative management of placenta accreta with variable success.

“Since the publication of the last version of this guideline there have been several cohort studies describing the use of interventional radiology in assisting surgical and conservative management of placenta accreta with variable success.”

Diagnostic difficulties probably explain the current wide variation in reported prevalence of placenta accreta ranging between 1 in 300 and 1 in 2000 pregnancies.

“These diagnostic difficulties probably explain the current wide variation in reported prevalence of placenta accreta ranging between 1 in 300 and 1 in 2000 pregnancies, [1][2][3][4][5]”

• cites [1] 1. Jauniaux E, Jurkovic D. Placenta accreta: pathogenesis of a 20th century iatrogenic uterine disease. Placenta 2012;33:244-51. sourceNot checked — no full text of the source
• cites [2] 2. Solheim KN, Esakoff TF, Little SE, Cheng YW, Sparks TN, Caughey AB. The effect of cesarean delivery rates on the future incidence of placenta previa, placenta accreta, and maternal mortality. J Matern Fetal Neonatal Med 2011;24:1341-6. sourceNot checked — no full text of the source
• cites [3] 3. Bowman ZS, Eller AG, Bardsley TR, Greene T, Varner MW, Silver RM. Risk factors for placenta accreta: a large prospective cohort. Am J Perinatol 2014;31:799-804. sourceNot checked — no full text of the source

Placenta praevia and placenta accreta are associated with high maternal and neonatal morbidity and mortality.

“Placenta praevia and placenta accreta are associated with high maternal and neonatal morbidity and mortality.[1][2][3][4][5]”

• cites [1] 1. Jauniaux E, Jurkovic D. Placenta accreta: pathogenesis of a 20th century iatrogenic uterine disease. Placenta 2012;33:244-51. sourceNot checked — no full text of the source
• cites [2] 2. Solheim KN, Esakoff TF, Little SE, Cheng YW, Sparks TN, Caughey AB. The effect of cesarean delivery rates on the future incidence of placenta previa, placenta accreta, and maternal mortality. J Matern Fetal Neonatal Med 2011;24:1341-6. sourceNot checked — no full text of the source
• cites [3] 3. Bowman ZS, Eller AG, Bardsley TR, Greene T, Varner MW, Silver RM. Risk factors for placenta accreta: a large prospective cohort. Am J Perinatol 2014;31:799-804. sourceNot checked — no full text of the source

Predictors for emergency delivery in women with placenta praevia can be used for individualised antenatal care regarding need for hospital admission, corticosteroid administration and timing of delivery.

“The results of these studies suggest that predictors for emergency delivery in women with placenta praevia can be used for individualised antenatal care regarding need for hospital admission, corticosteroid administration and timing of delivery.”

Admission to hospital during pregnancy is a risk factor for venous thromboembolism.

“Admission to hospital during pregnancy is a risk factor for venous thromboembolism.RCOG Green-top Guideline No. 37a addresses thromboprophylaxis during pregnancy, including women at increased risk of haemorrhage.”

• cites RCOG Green-top Guideline No. 37aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

There is no evidence to support the use of autologous blood transfusion for placenta praevia.

“There is no evidence to support the use of autologous blood transfusion for placenta praevia.89”

• cites [89] 89. Madsen K, Grønbeck L, Rifbjerg Larsen C, Østergaard J, Bergholt T, Langhoff-Roos J, et al. Educational strategies in performing cesarean section. Acta Obstet Gynecol Scand 2013;92:256-63. sourceNot checked — no full text of the source

Uterine compressive and endouterine sutures are well established techniques for the control of haemorrhage following atonic PPH.

“Uterine compressive and endouterine sutures are well established techniques for the control of haemorrhage following atonic PPH.”

• cites [104] 104. B-Lynch C, Coker A, Lawal AH, Abu J, Cowen MJ. The B-Lynch surgical technique for the control of massive postpartum haemorrhage: an alternative to hysterectomy? Five cases reported. Br J Obstet Gynaecol 1997;104:372-5. 105. 102. Yoong W, Ridout A, Memtsa M, Stavroulis A, Aref-Adib M, Ramsay-Marcelle Z, et al. Application of uterine compression suture in association with intrauterine balloon tamponade ('uterine sandwich') for postpartum hemorrhage. Acta Obstet Gynecol Scand 2012;91:147-51. sourceNot checked — no full text of the source

Multidisciplinary management in a maternity unit with access to maternal and neonatal intensive care is often required for women with placenta accreta spectrum.

“Multidisciplinary management in a maternity unit with access to maternal and neonatal intensive care is often required for women with placenta accreta spectrum.21,22,135,138”

• cites [21] 21. Shamshirsaz AA, Fox KA, Salmanian B, Diaz-Arrastia CR, Lee W, Baker BW, et al. Maternal morbidity in patients with morbidly adherent placenta treated with and without a standardized multidisciplinary approach. Am J Obstet Gynecol 2015;212:218.e1-9 sourceNot checked — no full text of the source
• cites [22] 22. Shamshirsaz AA, Fox KA, Erfani H, Clark SL, Salmanian B, Baker BW, et al. Multidisciplinary team learning in the management of the morbidly adherent placenta: outcome improvements over time. Am J Obstet Gynecol 2017;216:612.e1-e5. sourceNot checked — no full text of the source
• cites [135] 135. Silver RM, Fox KA, Barton JR, Abuhamad AZ, Simhan H, Huls CK, et al. Center of excellence for placenta accreta. Am J Obstet Gynecol 2015;212:561-8. sourceNot checked — no full text of the source
• cites [138] 138. Smulian JC, Pascual AL, Hesham H, Qureshey E, Bijoy Thomas M, Depuy AM, et al. Invasive placental disease: the impact of a multi- disciplinary team approach to management. J Matern Fetal Neonatal Med 2017;30:1423-7. sourceNot checked — no full text of the source

A 2010 decision analysis supports delivery at between 34 and 35 weeks of gestation for suspected placenta accreta spectrum based on the increasing likelihood of emergency delivery as pregnancy goes beyond 34 weeks of gestation.

“A 2010 decision analysis supports this approach based on the increasing likelihood of emergency delivery as pregnancy goes beyond 34 weeks of gestation.167”

• cites [167] 167. Robinson BK, Grobman WA. Effectiveness of timing strategies for delivery of individuals with placenta previa and accreta. Obstet Gynecol 2010;116:835-42. sourceNot checked — no full text of the source

In cases of deep placental invasion (increta and percreta), the mean gestational age at delivery is 33 +5 weeks of gestation compared with 35 +2 weeks of gestation in the superficial adherent group.

“The first study included 103 women delivered between 1982 and 2002 and found that the mean gestational age at delivery is 33 +5 weeks of gestation in cases of deep placental invasion (increta and percreta) compared with 35 +2 weeks of gestation in the superficial adherent group.168”

• cites [168] 168. Seet EL, Kay HH, Wu S, Terplan M. Placenta accreta: depth of invasion and neonatal outcomes. J Matern Fetal Neonatal Med 2012;25:2042-5. sourceNot checked — no full text of the source

Removal of a placenta accreta spectrum is associated with significant haemorrhagic morbidity.

“The ACOG recommends planned, preterm caesarean section hysterectomy with the placenta left in situ as removal of a placenta accreta spectrum is associated with significant haemorrhagic morbidity.165”

• cites [165] 165. Committee on Obstetric Practice. Committee opinion no. 529: placenta accreta. Obstet Gynecol 2012;120:207-11. sourceNot checked — no full text of the source

The incidence of urological complications is increased in placenta percreta, including cystotomy and ureteric injury.

“The incidence of urological complications is also increased, including cystotomy and ureteric injury.190”

• cites [190] 190. Woldu SL, Ordonez MA, Devine PC, Wright JD. Urologic considerations of placenta accreta: a contemporary tertiary care institutional experience. Urol Int 2014;93:74-9. sourceNot checked — no full text of the source

The incidence of postoperative complications of the Triple-P procedure depends on comorbidities and in particular, the placental position and the depth of villous invasion.

“The incidence of postoperative complications of the Triple-P procedure depends on comorbidities and in particular, the placental position and the depth of villous invasion.183”

• cites [183] 183. El Tahan M, Carrillo AP, Moore J, Chandraharan E. Predictors of postoperative hospitalisation in women who underwent the Triple-P Procedure for abnormal invasion of the placenta. J Obstet Gynaecol 2018;38:71-3. sourceNot checked — no full text of the source

Conservative expectant management with part of the placenta left in situ was successful in 131 out of 167 cases (78.4%; 95% CI 71.4-84.4).

“Conservative expectant management with part of the placenta left in situ was successful in 131 out of 167 cases (78.4%; 95% CI 71.4-84.4).195”

• cites [195] 195. Sentilhes L, Ambroselli C, Kayem G, Provansal M, Fernandez H, Perrotin F, et al. Maternal outcome after conservative treatment of placenta accreta. Obstet Gynecol 2010;115:526-34. sourceNot checked — no full text of the source

Planned cystotomy can prevent extensive muscularis damage and bleeding from attempts at dissection.

“Planned cystotomy can prevent extensive muscularis damage and bleeding from attempts at dissection.191”

• cites [191] 191. Norris BL, Everaerts W, Posma E, Murphy DG, Umstad MP, Costello AJ, et al. The urologist's role in multidisciplinary management of placenta percreta. BJU Int 2016;117:961-5. sourceNot checked — no full text of the source

A retrospective study of 57 cases of suspected accreta demonstrated significantly reduced short-term morbidity if the placenta is left in place and hysterectomy is performed electively compared with attempting to remove the placenta first.

“A retrospective study of 57 cases of suspected accreta demonstrated significantly reduced short-term morbidity if the placenta is left in place and hysterectomy is performed electively compared with attempting to remove the placenta first.177”

• cites [177] 177. Eller AG, Porter TF, Soisson P, Silver RM. Optimal management strategies for placenta accreta. BJOG 2009;116:648-54. sourceNot checked — no full text of the source

The placenta accreta care bundle was found to be both achievable and practical in a 5-month pilot study in six units.

“The care bundle was then tested in six units over a 5-month pilot study period and it was found to be both achievable and practical.”

• cites [173] 173. Paterson-Brown S, Singh C. Developing a care bundle for the management of suspected placenta accreta. The Obstetrician & Gynaecologist 2010;12:21-7. sourceNot checked — no full text of the source

Uterus preserving surgery is possible in placenta percreta as demonstrated in a cohort study of 71 women.

“Uterus preserving surgery is possible in placenta percreta as demonstrated in a cohort study of 71 women.”

• cites [193] 193. Shabana A, Fawzy M, Refaie W. Conservative management of placenta percreta: a stepwise approach. Arch Gynecol Obstet 2015;291:993-8. sourceNot checked — no full text of the source

An observational case series of 24 women with placenta accreta left in situ after delivery and treated with MTX reported placental delivery in 33.3% of the cases.

“An observational case series, including 24 women with placenta accreta left in situ after delivery and treated with MTX, reported placental delivery in 33.3% of the cases (spontaneously in 55%, and in 45% following dilatation and surgical evacuation).197”

• cites [197] 197. Lin K, Qin J, Xu K, Hu W, Lin J. Methotrexate management for placenta accreta: a prospective study. Arch Gynecol Obstet 2015;291:1259-64. sourceNot checked — no full text of the source

Attempting placental separation risks hysterectomy in up to 100% of cases.

“Attempting placental separation risks hysterectomy in up to 100% of cases as also confirmed by other authors.177,178”

• cites [177] 177. Eller AG, Porter TF, Soisson P, Silver RM. Optimal management strategies for placenta accreta. BJOG 2009;116:648-54. sourceNot checked — no full text of the source
• cites [178] 178. Hudon L, Belfort MA, Broome DR. Diagnosis and management of placenta percreta: a review. Obstet Gynecol Surv 1998;53: 509-17. 179. 105. Rossetti D, Vitale SG, Bogani G, Rapisarda AM, Gulino FA, Frigerio L. Usefulness of vessel-sealing devices for peripartum hysterectomy: a retrospective cohort study. Updates Surg 2015;67:301-4. sourceNot checked — no full text of the source

The choice of surgical technique for placenta accreta spectrum depends on the position of the placenta, the depth of invasion, the parametrial extension as assessed by ultrasound and/or MRI before delivery, the visual assessment of the uterus at the time of surgery, and the presenting clinical symptoms.

“The choice of surgical technique will depend on the position of the placenta, the depth of invasion, and the parametrial extension of the placenta accreta spectrum as assessed by ultrasound and/or MRI before delivery, the visual assessment of the uterus at the time of surgery and the presenting clinical symptoms, i.e. bleeding or no bleeding.5”

• cites [5] 5. Silver RM. Abnormal placentation: Placenta previa, vasa previa and placenta accreta. Obstet Gynecol 2015;126:654-68. sourceNot checked — no full text of the source

Both general and regional anaesthetic techniques have been shown to be safe for surgical procedures required for the delivery of placenta accreta spectrum.

“Both general and regional anaesthetic techniques have been shown to be safe for surgical procedures required for the delivery of placenta accreta spectrum; the judgment of which type of technique to be used should be made on an individual basis.166”

• cites [166] 166. Belfort MA. Indicated preterm birth for placenta accreta. Semin Perinatol 2011;35:252-6. sourceNot checked — no full text of the source

The majority of members of the US Society of Maternal-Fetal Medicine (SMFM) and FIGO expert panel proceed with hysterectomy in cases of high suspicion for accreta during caesarean delivery.

“In cases of high suspicion for accreta during caesarean delivery, the majority of members of the US Society of Maternal-Fetal Medicine (SMFM) and FIGO expert panel proceed with hysterectomy.[157][158][159][160][161]”

• cites [157] 157. Mehrabadi A, Hutcheon JA, Liu S, Bartholomew S, Kramer MS, Liston RM, et al.; Maternal Health Study Group of Canadian Perinatal Surveillance System (Public Health Agency of Canada). Contribution of placenta accreta to the incidence of postpartum hemorrhage and severe postpartum hemorrhage. Obstet Gynecol 2015;125:814-21. sourceNot checked — no full text of the source
• cites [158] 158. Jolley JA, Nageotte MP, Wing DA, Shrivastava VK. Management of placenta accreta: a survey of Maternal-Fetal Medicine practitioners. J Matern Fetal Neonatal Med 2012;25:756-60. sourceNot checked — no full text of the source
• cites [159] 159. Esakoff TF, Handler SJ, Granados JM, Caughey AB. PAMUS: placenta accreta management across the United States. J Matern Fetal Neonatal Med 2012;25:761-5. sourceNot checked — no full text of the source

Ureteric stents or catheters are more commonly used preoperatively in the USA where around 26% of the members of both the SMFM and ACOG fellows are using them in the management of suspected abnormally invasive placenta.

“Ureteric stents or catheters are more commonly used preoperatively in the USA where around 26% of the members of both the SMFM 158 and ACOG fellows 160 are using them in the management of suspected abnormally invasive placenta.”

• cites [158] 158. Jolley JA, Nageotte MP, Wing DA, Shrivastava VK. Management of placenta accreta: a survey of Maternal-Fetal Medicine practitioners. J Matern Fetal Neonatal Med 2012;25:756-60. sourceNot checked — no full text of the source
• cites [160] 160. Wright JD, Silver RM, Bonanno C, Gaddipati S, Lu YS, Simpson LL, et al. Practice patterns and knowledge of obstetricians and gynecologists regarding placenta accreta. J Matern Fetal Neonatal Med 2013;26:1602-9. sourceNot checked — no full text of the source

Urgent delivery for bleeding decreased significantly with advancing gestation in a study of 216 women.

“The second study of 216 women found that urgent delivery for bleeding decreased significantly with advancing gestation.169”

• cites [169] 169. Rac MW, Wells CE, Twickler DM, Moschos E, McIntire DD, Dashe JS. Placenta accreta and vaginal bleeding according to gestational age at delivery. Obstet Gynecol 2015;125: 808-13. sourceNot checked — no full text of the source

The most significant maternal risks associated with delivery in confirmed placenta accreta are the need for postpartum transfusion due to haemorrhage and peripartum hysterectomy.

“A review of 34 studies published between 1977 and 2012, including a total number of 508 617 deliveries and 865 cases of confirmed placenta accreta, found that the most significant maternal risks associated with delivery are the need for postpartum transfusion due to haemorrhage and peripartum hysterectomy.”

• cites [122] 122. Balayla J, Bondarenko HD. Placenta accreta and the risk of adverse maternal and neonatal outcomes. J Perinat Med 2013;41:141-9. sourceNot checked — no full text of the source

Reversible adverse effects related to prophylactic balloon catheter insertion were noted in 2/13 (15.4%) cases.

“Reversible adverse effects related to prophylactic balloon catheter insertion were noted in 2/13 (15.4%) cases.”

• cites [220] 220. Salim R, Chulski A, Romano S, Garmi G, Rudin M, Shalev E. Precesarean prophylactic balloon catheters for suspected placenta accreta: A randomized controlled trial. Obstet Gynecol 2015;126:1022-8. RCOG Green-top Guideline No. 126 e44 of e48 ª 2018 Royal College of Obstetricians and Gynaecologists 14710528, 2019, 1, Downloaded from https://obgyn.onlinelibrary.wiley.com/doi/10.1111/1471-0528.15306, Wiley Online Library on [01/09/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the sourceNot checked — no full text of the source

One woman in the observational case series suffered liver damage.

“One woman did suffer liver damage and the risks of this therapy must be balanced against the unproven benefit.”

• cites [197] 197. Lin K, Qin J, Xu K, Hu W, Lin J. Methotrexate management for placenta accreta: a prospective study. Arch Gynecol Obstet 2015;291:1259-64. sourceNot checked — no full text of the source

In rare cases, a disseminated intravascular coagulation may develop requiring a secondary hysterectomy.

“In rare cases, a disseminated intravascular coagulation may develop requiring a secondary hysterectomy.201”

• cites [201] sourceNot checked — no full text of the source

A small RCT of women with a prenatal diagnosis of placenta accreta found no difference between preoperative prophylactic balloon catheters and control for blood loss greater than 2500 ml, number of plasma products transfused, duration of surgery, peripartum complications and hospitalisation length.

“A small RCT of women presenting with a prenatal diagnosis of placenta accreta was published in 2015.220 The women were randomised to either preoperative prophylactic balloon catheters (n = 13) or to a control group (n = 14).No difference was observed for the number of women with blood loss greater than 2500 ml, number of plasma products transfused, duration of surgery, peripartum complications and”

• cites [220] 220. Salim R, Chulski A, Romano S, Garmi G, Rudin M, Shalev E. Precesarean prophylactic balloon catheters for suspected placenta accreta: A randomized controlled trial. Obstet Gynecol 2015;126:1022-8. RCOG Green-top Guideline No. 126 e44 of e48 ª 2018 Royal College of Obstetricians and Gynaecologists 14710528, 2019, 1, Downloaded from https://obgyn.onlinelibrary.wiley.com/doi/10.1111/1471-0528.15306, Wiley Online Library on [01/09/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the sourceNot checked — no full text of the source

A single institution observational cohort study of 45 cases of placenta accreta found that prophylactic lower abdominal aorta balloon occlusion reduced the need for blood transfusion.

“A single institution observational cohort study of 45 cases of placenta accreta describes the use of prophylactic lower abdominal aorta balloon occlusion and found a reduced need for blood transfusion.209”

• cites [209] 209. Wei X, Zhang J, Chu Q, Du Y, Xing N, Xu X, et al. Prophylactic abdominal aorta balloon occlusion during caesarean section: a retrospective case series. Int J Obstet Anesth 2016;27:3-8. sourceNot checked — no full text of the source

These risks are particularly high when the caesarean section takes place in an environment with no emergency access to blood bank products and expertise in managing placenta accreta.

“These risks are particularly high when the caesarean section takes place in an environment with no emergency access to blood bank products and expertise in managing placenta accreta.20,21,122,135”

• cites [20] 20. Bowman ZS, Manuck TA, Eller AG, Simons M, Silver RM. Risk factors for unscheduled delivery in patients with placenta accreta. Am J Obstet Gynecol 2014;210:241.e1-6. sourceNot checked — no full text of the source
• cites [21] 21. Shamshirsaz AA, Fox KA, Salmanian B, Diaz-Arrastia CR, Lee W, Baker BW, et al. Maternal morbidity in patients with morbidly adherent placenta treated with and without a standardized multidisciplinary approach. Am J Obstet Gynecol 2015;212:218.e1-9 sourceNot checked — no full text of the source
• cites [122] 122. Balayla J, Bondarenko HD. Placenta accreta and the risk of adverse maternal and neonatal outcomes. J Perinat Med 2013;41:141-9. sourceNot checked — no full text of the source