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Cited by 66Sperm and Testicular FunctionReproductive Health and TechnologiesMale Reproductive Health Studies

Men with a complete absence of normal sperm morphology exhibit high rates of success without assisted reproduction

Open access
Smith, RyanP, Kovac, JasonR, Cajipe, Miguel, Lamb, DoloresJ, Lipshultz, LarryI·2017·Asian Journal of Andrology
DOI 10.4103/1008-682x.189211PMC PMC5227671
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Abstract

In couples with infertility, abnormal strict morphology of 0% normal forms (NF) is a criterion to proceed rapidly to in vitro fertilization (IVF). Since no data currently exist, we investigated the outcomes for men with 0% NF to determine reproductive success without the use of assisted reproductive technologies (ART). A cohort of 24 men with 0% NF were identified (2010-2013) with 27 randomly selected men with ≥4% NF as controls. Patient charts were reviewed with men contacted and administered an Institutional Review Board (IRB)-approved telephone questionnaire to ascertain outcomes. After a median follow-up time of 2.5 years, 29.2% of men with 0% NF did not require ART for their first pregnancy (controls = 55.6%, P ≤ 0.05). When all pregnancies were analyzed together, men with 0% NF achieved twenty pregnancies of which 75% did not require IVF (controls = thirty pregnancies; 76.7% did not require IVF). The average age of men and female partners was similar between men with 0% NF and ≥4% NF. All men had normal follicle-stimulating hormone (FSH), testosterone, prolactin, sex hormone-binding globulin (SHBG), and estradiol. Although, global semen parameters were worse in men with 0% NF, when a first pregnancy was a natural conception (NC), 100% of men with 0% NF (n = 7/7) and 37.5% of controls (n = 3/8) went on to have a subsequent pregnancy via NC. Men with 0% NF conceived without IVF in 29.2% of cases compared to 55.6% of controls. Strict morphology should not be used to predict fertilization, pregnancy, or live birth potential. In men with 0% NF, alternative modalities should be considered before immediate IVF.

AI snapshot

Written from the paper’s full text.

TL;DR

In a retrospective cohort, men with 0% normal sperm morphology still achieved natural conception and pregnancies without IVF at substantial rates, though lower than controls for first pregnancy. The authors conclude strict morphology should not be used to predict fertilization, pregnancy, or live birth potential or to proceed directly to IVF.

Key findings

  • Among 24 men with 0% normal forms (NF) versus 27 controls with ≥4% NF, after median 2.5 years, 29.2% (7/24) of men with 0% NF achieved a first pregnancy/live birth without IVF versus 55.6% (15/27) of controls (P ≤ 0.05).
  • First-pregnancy natural conception occurred in 25% (6/24) of men with 0% NF versus 51.8% of controls (P ≤ 0.05).
  • Across all pregnancies, men with 0% NF achieved 20 pregnancies, of which 75% (15/20) did not require IVF; controls achieved 30 pregnancies, of which 76.7% did not require IVF.
  • When first pregnancy was a natural conception, 100% (7/7) of men with 0% NF went on to have a subsequent natural-conception pregnancy, versus 37.5% (3/8) of controls.

Methods

  • Retrospective chart review at a high-volume tertiary academic infertility clinic from 2010–2013; 156 men with strict morphology were examined, identifying 24 men with 0% NF and 27 randomly selected controls with ≥4% NF. Men were contacted for an IRB-approved telephone questionnaire; exclusions included refusal/uncontactable status and adoption or donor sperm use, and only live births or current pregnancies were analyzed.
  • Strict morphology used Kruger criteria with 200 sperm analyzed at ×100 oil immersion; semen analyses and serum hormones were performed at the same laboratory (LMRRT, Baylor College of Medicine). Only initial values were used when multiple results existed.
  • Analysis used Student’s t-test with P ≤ 0.05 considered significant, performed in Microsoft Excel and GraphPad Prism 6; values reported as mean ± standard error of the mean unless otherwise noted.

Limitations

  • The authors state the study lacks the rigor of a randomized controlled trial; the population was mostly men experiencing fertility issues and may differ from the general population; and IUI/IVF procedures were conducted by different reproductive endocrinologists, potentially leading to variable results.
  • The authors assert recall bias was eliminated by parents remembering offspring birthdays and selection bias was resolved by using continuous patients from 2010–2014.
  • Evident from the text: the sample is small (24 men with 0% NF and 27 controls), the design is retrospective and single-center, outcomes were ascertained by telephone questionnaire, and the paper itself notes sperm morphology assessment remains subjective with inter- and intra-laboratory differences.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.4103/1008-682x.189211

Cites

28 of 28 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

7 of 15 cited sources checked · 3 supported · 0 flagged · accuracy not yet measured

  • Findingown data

    When the first pregnancy was a natural conception, 100% (7/7) of men with 0% NF and 37.5% (3/8) of controls went on to have a subsequent pregnancy via natural conception.

    “when a first pregnancy was a natural conception (NC), 100% of men with 0% NF (n = 7/7) and 37.5% of controls (n = 3/8) went on to have a subsequent pregnancy via NC.”
    • Also stated in: § RESULTS · plain
      “In cases where men with 0% NF had a child via NC, 100% of them had another child with NC.”
    • Also stated in: § RESULTS · plain
      “In men with 0% NF and in whom the first pregnancy was conceived without IVF (n = 7), 100% had successful NCs on subsequent occasions.”
    Quote in the paperSubstantial claim
  • Findingown data

    Men with 0% NF had significantly worse global semen parameters than control men, except for semen volume.

    “As expected, the semen analysis found that men with 0% NF had, with the exception of volume, significantly worse parameters than control men (Table 1).”
    • Also stated in: § Abstract · plain
      “Although, global semen parameters were worse in men with 0% NF”
    Quote in the paperNot a substantial claim
  • Findingown data

    Serum testosterone, sex hormone-binding globulin (SHBG), prolactin, and estradiol levels were similar between men with 0% NF and controls.

    “When examining serum hormone levels, testosterone, sex hormone-binding globulin (SHBG), prolactin, and estradiol were similar among the groups (Table 1).”
    Quote in the paperNot a substantial claim
  • Premisecitation

    Sperm morphology assessment remains subjective to inter- and intra-laboratory differences.

    “While sperm morphology is guided by specific criteria, it still remains subjective to inter- and intra-laboratory differences.4”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [4] Franken DR Menkveld R Kruger TF Sekadde-Kigondu C Lombard C Monitoring technologist reading skills in a sperm morphology quality control program Fertil Steril 2003 79 Suppl 3 1637 43 12801571 source
  • Interpretationown data

    Men with a complete absence of normal forms (0%) on strict morphology exhibit high rates of success without IVF.

    “Men with 0% NF conceived without IVF in 29.2% of cases compared to 55.6% of controls.”
    • Also stated in: § DISCUSSION · plain
      “In summary, men with a complete absence of NF (0%) on strict morphology exhibit high rates of success without IVF.”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim. 19
  • May combine two claims. 9

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Spermatozoa in cervical mucus cannot be proven to be functionally better than those with the same appearance and form in seminal plasma.

    “As a manner of illustration, consider that spermatozoa in the cervical mucus cannot be proven to be functionally better than those with the same appearance and form in the seminal plasma.23”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [23] Eliasson R Semen analysis with regard to sperm number, sperm morphology and functional aspects Asian J Androl 2010 12 26 32 20111078 PMC3739674 source

      The Introduction discusses sperm function, and section 5 discusses morphology, but neither compares spermatozoa in cervical mucus with similarly shaped spermatozoa in seminal plasma. Searches for “cervical mucus” and for the claimed functional comparison found no passage addressing it in our copy. (LLM, conf=0.72)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The ability of sperm morphology to predict in vitro reproductive outcomes was first proposed by Kruger et al., who noted an inverse relationship between successful oocyte fertilization and sperm morphology.

    “The ability of sperm morphology to predict in vitro reproductive outcomes was first proposed by Kruger et al.12 who noted an inverse relationship between successful oocyte fertilization and sperm morphology.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [12] Keegan BR Barton S Sanchez X Berkeley AS Krey LC Isolated teratozoospermia does not affect in vitro fertilization outcome and is not an indication for intracytoplasmic sperm injection Fertil Steril 2007 88 1583 8 17448467 source

      The paper’s introductory passage (page unavailable) says Kruger et al. published a novel sperm-morphology assessment in 1986 and correlated it with IVF fertilization likelihood. It does not support the stated inverse relationship with normal sperm morphology: the passage says fertilization rates were lower when the percentage of normal sperm was low. The Discussion also reports that this paper’s own study found no difference in fertilization rates by morphology. (LLM, conf=0.87)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Studies examining sperm morphology and pregnancy outcomes following IUI and IVF have produced variable results.

    “In the context of these aforementioned limitations, studies have been performed examining sperm morphology and pregnancy outcomes following IUI7891011 and IVF112131415161718 with variable results.”
    Quote in the paperNot a substantial claim2 of 3 sources checked
    • cites [7] Morbeck DE Leonard PH Weaver AL Shimek KM Bouwsma EV Sperm morphology: classification drift over time and clinical implications Fertil Steril 2011 96 1350 4 21958691 source

      The Results and Discussion report that sperm morphology predicted clinical pregnancy after IUI in the earlier era but not the later era, supporting variable IUI findings. The paper mentions IVF in its background but does not examine pregnancy outcomes following IVF, so it does not support that part of the claim. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [8] Badawy A Elnashar A Eltotongy M Effect of sperm morphology and number on success of intrauterine insemination Fertil Steril 2009 91 777 81 18304534 source
    • cites [9] Matorras R Corcostegui B Perez C Mandiola M Mendoza R Sperm morphology analysis (strict criteria) in male infertility is not a prognostic factor in intrauterine insemination with husband's sperm Fertil Steril 1995 63 608 11 7851595 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Some investigators have recommended IVF with ICSI in cases of isolated teratozoospermia.

    “Indeed, some investigators have recommended IVF with ICSI in cases of isolated teratozoospermia.21”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [21] McKenzie LJ Kovanci E Amato P Cisneros P Lamb D Pregnancy outcome of in vitro fertilization/intracytoplasmic sperm injection with profound teratospermia Fertil Steril 2004 82 847 9 15482758 source

      The paper says most centers perform ICSI for severe teratospermia and concludes that IVF/ICSI yielded acceptable pregnancy rates in its small group with 0% normal sperm morphology (Abstract; Discussion). It does not establish a recommendation specifically for isolated teratozoospermia: the Semen Parameters section reports variation in sperm concentration and motility, rather than restricting the group to men whose only abnormal parameter was morphology. (LLM, conf=0.87)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Semen parameters have traditionally been used as an indicator for oocyte fertilization and attainment of pregnancy.

    “Among the many factors that influence the outcomes of IVF, semen parameters have traditionally been used as an indicator for oocyte fertilization and attainment of pregnancy in addition to the quality of the oocyte.20”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [20] Ghirelli-Filho M Mizrahi FE Pompeo AC Glina S Influence of strict sperm morphology on the results of classic in vitro fertilization Int Braz J Urol 2012 38 519 28 22951162 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Selection for morphologically normal human spermatozoa within the cervical mucus exists.

    “Previously, Mortimer and Templeton2425 confirmed the existence of selection for morphologically normal human spermatozoa within the cervical mucus.”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [24] Mortimer D Leslie EE Kelly RW Templeton AA Morphological selection of human spermatozoa in vivo and in vitro J Reprod Fertil 1982 64 391 9 7069658 source
    • cites [25] Mortimer D Templeton AA Sperm transport in the human female reproductive tract in relation to semen analysis characteristics and time of ovulation J Reprod Fertil 1982 64 401 8 6461762 source

  • May combine two claims.

    Findingown data

    In men with 0% NF, natural conception occurred in 25% (6/24) of cases, compared with 51.8% of control men (P ≤ 0.05).

    “In men with 0% NF, a NC occurred 25% of the time (n = 6/24) while controls were able to conceive naturally in 51.8% of cases (P ≤ 0.05) (Figure 1b).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Luteinizing hormone (LH) was lower than normal in both groups but significantly higher in men with 0% NF.

    “Furthermore, the luteinizing hormone (LH) was lower than normal in both groups but significantly higher in men with 0% NF (Table 1).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Follicle-stimulating hormone (FSH) was within the normal range in both groups but was significantly greater in men with 0% NF.

    “The follicle-stimulating hormone (FSH) was with the normal range for both 0% NF and controls; however, it was significantly greater in men with 0% NF.”
    • Also stated in: § Abstract · plain
      “All men had normal follicle-stimulating hormone (FSH), testosterone, prolactin, sex hormone-binding globulin (SHBG), and estradiol.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Among men with 0% normal forms (NF), 29.2% (7/24) achieved a first pregnancy without IVF/ART, compared with 55.6% (15/27) of control men with ≥4% NF (P ≤ 0.05).

    “After a median follow-up time of 2.5 years, 29.2% of men with 0% NF did not require ART for their first pregnancy (controls = 55.6%, P ≤ 0.05).”
    • Also stated in: § RESULTS · plain
      “29.2% of men with 0% NF were able to conceive without the use of IVF (n = 7/24) compared to 55.6% of control men (n = 15/27) (P ≤ 0.05) (Figure 1a).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    When all pregnancies were analyzed, men with 0% NF achieved 20 pregnancies, 75% (15/20) of which did not require IVF; control men achieved 30 pregnancies, 76.7% of which did not require IVF.

    “When all pregnancies were analyzed together, men with 0% NF achieved twenty pregnancies of which 75% did not require IVF (controls = thirty pregnancies; 76.7% did not require IVF).”
    • Also stated in: § RESULTS · plain
      “Men with 0% NF produced twenty pregnancies and 75% (n = 15/20) did not require IVF while thirty pregnancies were achieved in control men with 76.7% not requiring IVF (Figure 1c).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Classification drift exists between different classification systems (e.g., WHO 2nd, 3rd).

    “Furthermore, studies have identified a classification drift between different classification systems (i.e., WHO 2nd, 3rd, etc.)56”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [5] Cooper TG Neuwinger J Bahrs S Nieschlag E Internal quality control of semen analysis Fertil Steril 1992 58 172 8 1624001 source
    • cites [6] Horte A Vierula M Toppari J Suominen J Reassessment of sperm morphology of archival semen smears from the period 1980-1994 Int J Androl 2001 24 120 4 11298846 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    All semen analyses and strict morphologies were performed at the same laboratory (LMRRT, BCM) to account for differences in technique and equipment.

    “All semen analyses and strict morphologies were also performed at the LMRRT (BCM) to account for differences in technique and equipment.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Study design and conductown data

    The average age of men and their female partners and the average follow-up times did not differ significantly between men with 0% NF and controls.

    “The average age at time of evaluation of both men and their female partners was not significantly different and neither were the average follow-up times (Table 1).”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    A study published in The Lancet noted that in men with an increased proportion of sperm with abnormal morphology, the likelihood of pregnancy was decreased.

    “These findings were propagated by a study published in The Lancet3 that noted in men with an increased proportion of sperm with abnormal morphology, and the likelihood of pregnancy was decreased.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [3] Bonde JP Ernst E Jensen TK Hjollund NH Kolstad H Relation between semen quality and fertility: a population-based study of 430 first-pregnancy planners Lancet 1998 352 1172 7 9777833 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    IUI and IVF procedures were conducted by different reproductive endocrinologists, potentially leading to variable results.

    “Moreover, IUI and IVF procedures were conducted by different reproductive endocrinologists potentially leading to variable results.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Study design and conductnone given

    The use of continuous patients (2010-2014) resolved potential selection bias.

    “Furthermore, the usage of continuous patients (2010–2014) resolved potential selection bias.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationnone given

    Sperm morphology does not indicate the genetic composition of spermatozoa or their fertilization potential.

    “Morphology does not indicate anything with regard to the genetic composition of the spermatozoa or the fertilization potential.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    In 1986, Kruger et al. published a classification system to evaluate sperm morphology and correlate it with the likelihood of IVF outcomes in terms of fertilization and clinical pregnancy.

    “In 1986, Kruger et al.2 published a novel classification system to evaluate sperm morphology and correlate it with the likelihood of IVF outcomes in terms of fertilization and clinical pregnancy.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [2] Kruger TF Menkveld R Stander FS Lombard CJ Van der Merwe JP Sperm morphologic features as a prognostic factor in in vitro fertilization Fertil Steril 1986 46 1118 23 2946611 source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    The population of men seen was limited mostly to those experiencing fertility issues and may be different from the general population.

    “Despite this, the population of men seen was limited, mostly, to those experiencing fertility issues and as such, may be different in the general populations.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisenone given

    Variability in IUI and IVF outcomes for men with teratozoospermia has resulted in controversy in how to counsel men with isolated defects in strict morphology.

    “Variability in IUI and IVF outcomes for men with teratozoospermia has resulted in controversy in how to counsel men with isolated defects in strict morphology.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Premisenone given

    The presumed importance of strict morphology remains incompletely documented.

    “Despite their efforts and those of others, the presumed importance of strict morphology remains incompletely documented.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    The selection of spermatozoa in the cervical canal is facilitated by reductions in spermatozoa with midpiece, tail, and other morphological defects that would be expected to impair motility.

    “Later, Mortimer26 by evaluating sperm recovered from the cervical canal, further delineated that the selection of spermatozoa is facilitated by reductions in spermatozoa with midpiece, tail, and other morphological defects which would be expected to impair motility.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [26] Mortimer D Sperm recovery techniques to maximize fertilizing capacity Reprod Dev 1994 6 25 31 8066218 source

  • Classified as probably not a substantial claim.

    Study design and conductown data

    Strict morphology was evaluated using the Kruger strict criteria, with two hundred sperm analyzed at ×100 under oil immersion.

    “Strict morphology was evaluated using the Kruger strict criteria. In brief, an aliquot of semen was air-dried and stained using Diff-Quik Stain Set (Baxter Scientific, Deerfield, IL, USA) with two hundred sperm analyzed at ×100 with an oil-immersion lens.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Study design and conductreasoning

    Recall bias was eliminated by the tendency of parents to remember the birthdays of their offspring.

    “When considering limitations, recall bias was eliminated by the tendency of parents to remember the birthdays of their offspring.”
    Quote in the paperNot a substantial claim
25 of 25

  • The paper relies on this without support.

    No studies have been conducted examining teratozoospermia and the likelihood of achieving natural conception.

    “To date, no studies have been conducted examining teratozoospermia and the likelihood of achieving a natural conception (NC).”

  • The paper relies on this without support.

    Abnormal strict morphology of 0% normal forms is a criterion to proceed rapidly to IVF.

    “In couples with infertility, abnormal strict morphology of 0% normal forms (NF) is a criterion to proceed rapidly to in vitro fertilization (IVF).”
    “Indeed, an abnormal strict morphology identifying severe teratozoospermia, or 0% normal forms (NF), has often been used as a criterion to proceed directly to in vitro fertilization (IVF).”
2 of 2

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • There is a high prevalence of severe teratozoospermia in fertile men.

    “Recently, some authors have shown the high prevalence of severe teratozoospermia in fertile men [9, 10] and pointed out the low clinical value of this test [11].”

    From Recommendations for Human Sperm Morphology Assessment in 2025: An Expert Review From the French BLEFCO Group (2026) · cites this paper as [9]

    The Results report that some men with severe teratozoospermia (0% normal forms) conceived naturally. But the study selected men undergoing an infertility work-up and measured conception among those with severe teratozoospermia; it did not measure how prevalent severe teratozoospermia is among fertile men. (LLM, conf=0.85)

    Experimental — accuracy not yet measured

  • Publications examining the impact of morphology on spontaneous pregnancy, intrauterine insemination, and in vitro fertilization reach varying conclusions.

    “Despite efforts to standardize methodology for grading sperm morphology, publications examining the impact morphology on spontaneous pregnancy, intrauterine insemination, and in vitro fertilization reach varying conclusions (2, 3, 4, 5, 6, 7, 8, 9, 10).”

    From Poor reproducibility of percentage of normally shaped sperm using the World Health Organization Fifth Edition strict grading criteria (2022) · cites this paper as [4]

    The Introduction (page not provided) explicitly says studies of sperm morphology and pregnancy outcomes after IUI and IVF have had variable results. It does not establish varying conclusions among publications on spontaneous pregnancy; instead, it says no prior studies had examined teratozoospermia and the likelihood of natural conception. (LLM, conf=0.86)

    Experimental — accuracy not yet measured

  • Kovac et al. contended that sperm morphology assessment may not be a reliable indicator of fertility potential.

    “and hence they contended that sperm morphology assessment may not be a reliable indicator of fertility potential.”

    From Isolated teratozoospermia: revisiting its relevance in male infertility: a narrative review (2024) · cites this paper as [82]

  • Kovac et al. found that up to 30% of couples with men with absolute teratozoospermia (0% normal forms) could still conceive spontaneously.

    “Kovac et al. (82) found that up to 30% of couples with men with absolute teratozoospermia (0% normal forms) could still conceive spontaneously”

    From Isolated teratozoospermia: revisiting its relevance in male infertility: a narrative review (2024) · cites this paper as [82]

  • A diminished seminal antioxidant capacity was considered a vital component of the mechanism in sperm cell death-mediated DNA breaks among teratozoospermic semen.

    “A diminished seminal antioxidant capacity was also considered a vital component of the mechanism in sperm cell death-mediated DNA breaks among teratozoospermic semen (82).”

    From Isolated teratozoospermia: revisiting its relevance in male infertility: a narrative review (2024) · cites this paper as [82]

    The Discussion (page unavailable) mentions oviductal cells protecting sperm from oxidative stress, but does not address diminished seminal antioxidant capacity or sperm-cell-death-mediated DNA breaks. Searches for those terms and for DNA fragmentation or apoptosis found no passage supporting the claimed mechanism. (LLM, conf=0.76)

    Experimental — accuracy not yet measured

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Seven first natural conceptions conflict with six reported natural conceptions

    Minor

    The abstract describes seven men whose first pregnancy was a natural conception, whereas the results report six men with 0% NF conceiving naturally. Seven is instead the reported number who conceived without IVF.

  • Patient inclusion years differ

    Minor

    The methods say patients were reviewed from 2010 to 2013, but the discussion describes the patients as spanning 2010-2014.

  • Reported live-birth rate does not match cycles and deliveries

    Minor

    The stated 47 090 live-birth deliveries divided by 147 260 cycles gives about 32.0%, not 37%.

    Reported 37 · recomputed 31.977455

  • Figure caption names the control group as both comparison groups

    Minor

    The caption says controls are compared with men with ≥4% normal forms, although the results identify the ≥4% group as the controls and the 0% group as their comparison.

  • Natural-conception rate is reported as 29.2% instead of 25%

    Minor

    The discussion calls 29.2% the rate of successful natural conception, but the results report natural conception in 6 of 24 men (25%). The 29.2% figure includes pregnancies achieved without IVF, a broader category.

5 of 5

Cited works that were retracted

Works this paper cites that were later retracted, from the retraction notices publishers deposit. Major when the notice came out before this paper was published.

  • Cites a retracted work: 10.1016/j.fertnstert.2007.12.010

    Major

    The cited work was retracted on 2009-03-01 (notice 10.1016/j.fertnstert.2007.12.010), before this paper was published (2017). Its authors could have known.

    Cited work 10.1016/j.fertnstert.2007.12.010 · retracted 2009-03-01 · notice 10.1016/j.fertnstert.2007.12.010 · this paper published 2017

1 of 1

Cites

1 retracted

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Related

Authors
Smith, R., Kovac, J., Cajipe, M., Lamb, D., & Lipshultz, L.
Affiliations
  • University of Virginia (US)
  • Baylor College of Medicine (US)
Corresponding author
Smith, RyanP
Venue
Asian Journal of Andrology
Publisher
Ovid Technologies (Wolters Kluwer Health)
Published
2017
Volume
19
Issue
1
Pages
39
ISSN
1008-682X (ISSN-L)
DOI
10.4103/1008-682x.189211
PMC
PMC5227671
OpenAlex
W2518492686
Cited by
66
References
28
Citations by year
2026: 4 · 2025: 6 · 2024: 9 · 2023: 5 · 2022: 7 · 2021: 11 · 2020: 6 · 2019: 6 · 2018: 8 · 2017: 4
FWCI
6.74
Type
journal article
Language
en
Open access
Licence
cc-by-nc-sa
Locations
  • Asian Journal of Andrology (publishedVersion, cc-by-nc-sa)
  • PubMed (publishedVersion)
  • PubMed Central (submittedVersion, cc-by-nc-sa)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Topics
  • Health Sciences › Medicine › Reproductive Medicine › Sperm and Testicular Function
  • Health Sciences › Medicine › Reproductive Medicine › Reproductive Health and Technologies
  • Health Sciences › Health Professions › General Health Professions › Male Reproductive Health Studies
Keywords
sperm morphology, male infertility, spontaneous conception, pregnancy outcomes, assisted reproduction, in vitro fertilization, semen parameters, fertility prediction
MeSH terms
Teratozoospermia, Adult, Estradiol, Female, Fertilization in Vitro, Follow-Up Studies, Follicle Stimulating Hormone, Humans, Luteinizing Hormone, Male, Pregnancy, Prolactin, Severity of Illness Index, Sex Hormone-Binding Globulin, Spermatozoa, Testosterone, Case-Control Studies, Pregnancy Rate, Reproductive Techniques, Assisted

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Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-26.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-26.

Cited sources are checked by gpt-6-sol.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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