The DOI matches its Crossref record; 71 of the 72 references it cites were found in a registry or an index.
Associations between Perfluoroalkyl acids (PFASs) and maternal thyroid hormones in early pregnancy: A population-based cohort study
Abstract
Background Associations between perfluoroalkyl acids (PFASs) and human thyroid hormone levels remain unclear, especially during early pregnancy when small changes in maternal thyroid hormones can affect fetal brain development.Objectives To examine associations between maternal serum PFAS levels and maternal thyroid hormone levels in the early 2nd trimester of pregnancy.Methods Participants were euthyroid pregnant women (n=152) enrolled in the Chemicals, Health and Pregnancy (CHirP) study based in Vancouver, Canada. Associations between maternal serum PFASs, including perfluorohexanesulfonate (PFHxS), perfluorononanoate (PFNA), perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) and repeated measures of maternal thyroid hormones, including free thyroxine (fT4), total thyroxine (TT4) and thyroid stimulating home (TSH) were examined using mixed effects linear models. Associations were considered in all women, then separately in women with high (≥ 9 IU/mL) vs normal (<9 IU/mL) levels of thyroid peroxidase antibody (TPOAb), a marker of autoimmune hypothyroidism (Hashimoto's disease).Results Median PFAS concentrations (ng/mL) in maternal sera were 1.0 (PFHxS), 0.6 (PFNA), 1.7 (PFOA) and 4.8 (PFOS). PFASs were not associated with fT4, TT4 or TSH among women with normal TPOAb. However, among the 9% of women with high TPOAb (n=14), interquartile range (IQR) increases of PFASs were associated with a 46-69% increase in maternal TSH (95% CIs ranging from 8% to 123%) (PFNA, PFOA and PFOS only), and with a 3% to 7% decrease in maternal fT4 (95% CIs ranging from -18% to 5%) (all 4 PFASs). PFNA was also associated with higher maternal TSH in the whole sample.Conclusions PFASs were positively associated with TSH, and weakly negatively associated with fT4 in the subset of pregnant women with high TPOAb, which occurs in 6-10% of pregnancies. PFASs may exacerbate the already high TSH and low fT4 levels in these women during early pregnancy, which is a critical time of thyroid hormone-mediated fetal brain development. The clinical significance of these findings is not clear. We propose a "multiple hit hypothesis" to explain these findings; this hypothesis deserves evaluation in larger, more representative study samples.
Overview
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
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?
In the citing paper
“A majority of evidence for PFAS-induced endocrine disruption is at the level of circulating stress, sex, and thyroid hormones, while data regarding PFAS associated disruption of synthesis enzymes and receptors is more limited, especially within the brain”
From A Critical Review and Meta-Analysis of Impacts of Per- and Polyfluorinated Substances on the Brain and Behavior (2022) · cites this paper as Webster et al., 2014
In the citing paper
“The three studies proposed that higher PFC serum levels might change thyroid hormone levels [26–28]; however, the results of these studies were contradictory in some aspects, such as serum PFC-related increases in T4 and fT4 and decreases in T3 and hypothyroidism.”
From Overview of emerging contaminants and associated human health effects (2015) · cites this paper as [28]
In the citing paper
“The three studies proposed that higher PFC serum levels might change thyroid hormone levels [26–28]; however, the results of these studies were contradictory in some aspects, such as serum PFC-related increases in T4 and fT4 and decreases in T3 and hypothyroidism.”
From Overview of emerging contaminants and associated human health effects (2015) · cites this paper as [28]
Citations
Cites
The importance of selenium to human health
Rayman, M. P. (2000) · The Lancet · doi:10.1016/s0140-6736(00)02490-9 · Cited by 4,163
Estimation of Average Concentration in the Presence of Nondetectable Values
Hornung, R. W., & Reed, L. D. (1990) · Applied Occupational and Environmental Hygiene · doi:10.1080/1047322x.1990.10389587 · Cited by 3,495
Haddow, J. E., Palomaki, G. E., Allan, W. C., Williams, J. R., Knight, G. J., Gagnon, J., O'Heir, C. E., Mitchell, M. L., Hermos, R. J., Waisbren, S. E., et al. (1999) · New England Journal of Medicine · doi:10.1056/nejm199908193410801 · Cited by 2,558
Fluorinated Surfactants and Repellents
(2001) · Textile Research Journal · doi:10.1177/004051750107100823 · Cited by 1,376
Calafat, A. M., Wong, L.-Y., Kuklenyik, Z., Reidy, J. A., & Needham, L. L. (2007) · Environmental Health Perspectives · doi:10.1289/ehp.10598 · Cited by 1,247
Thyroid Function and Human Reproductive Health
Krassas, G. E., Poppe, K., & Glinoer, D. (2010) · Endocrine Reviews · doi:10.1210/er.2009-0041 · Cited by 1,223
Perfluorooctanesulfonate and related fluorochemicals in human blood from several countries
Kannan, K., Corsolini, S., Falandysz, J., Fillmann, G., Kumar, K. S., Loganathan, B. G., Mohd, M. A., Olivero, J., Wouwe, N. V., Yang, J. H., et al. (2004) · Environmental Science & Technology · doi:10.1021/es0493446 · Cited by 1,056
Pop, V. J., Kuijpens, J. L. P., van Baar, A. L., Verkerk, G. J. M., van Son, M. J. M., de Vijlder, J. J. M., Vulsma, T., Wiersinga, W. M., Drexhage, H. A., & Vader, H. L. (1999) · Clinical Endocrinology · doi:10.1046/j.1365-2265.1999.00639.x · Cited by 1,006
Role of thyroid hormone during early brain development
de Escobar, G. M., Obregón, M.-J., & del Rey, F. E. (2004) · European Journal of Endocrinology · doi:10.1530/eje.0.151u025 · Cited by 829
Pop, V. J., Brouwers, E. P. M., Vader, H. L., Vulsma, T., van Baar, A. L., & de Vijlder, J. J. M. (2003) · Clinical Endocrinology · doi:10.1046/j.1365-2265.2003.01822.x · Cited by 727
de Escobar, G. M., Obregón, M.-J., & del Rey, F. E. (2000) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jcem.85.11.6961 · Cited by 626
Zoeller, R. T., & Rovet, J. (2004) · Journal of Neuroendocrinology · doi:10.1111/j.1365-2826.2004.01243.x · Cited by 605
Subchronic Toxicity Studies on Perfluorooctanesulfonate Potassium Salt in Cynomolgus Monkeys
Seacat, A. M. (2002) · Toxicological Sciences · doi:10.1093/toxsci/68.1.249 · Cited by 564
Exposure to Perfluorooctane Sulfonate during Pregnancy in Rat and Mouse. II: Postnatal Evaluation
Lau, C., Thibodeaux, J. R., Hanson, R. G., Rogers, J. M., Grey, B. E., Stanton, M. E., Butenhoff, J. L., & Stevenson, L. A. (2003) · Toxicological Sciences · doi:10.1093/toxsci/kfg122 · Cited by 549
Biomonitoring of Perfluoroalkyl Acids in Human Urine and Estimates of Biological Half-Life
Zhang, Y., Beesoon, S., Zhu, L., & Martin, J. W. (2013) · Environmental Science & Technology · doi:10.1021/es401905e · Cited by 530
Self-citationMelzer, D., Rice, N., Depledge, M. H., Henley, W. E., & Galloway, T. S. (2010) · Environmental Health Perspectives · doi:10.1289/ehp.0901584 · Cited by 496
Perinatal outcome in hypothyroid pregnancies
Leung, A. S., Millar, L. K., Koonings, P. P., Montoro, M., & Mestman, J. H. (1993) · International Journal of Gynecology & Obstetrics · doi:10.1016/0020-7292(93)90343-u · Cited by 475
Henrichs, J., Bongers‐Schokking, J. J., Schenk, J. J., Ghassabian, A., Schmidt, H. G., Visser, T. J., Hooijkaas, H., Keizer‐Schrama, S. M. P. F. D. M., Albert Hofman, D., Jaddoe, V. V. W., et al. (2010) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2010-0415 · Cited by 468
Inoue, K., Okada, F., Ito, R., Kato, S., Sasaki, S., 中島そのみ, Uno, A., Saijo, Y., Sata, F., Yoshimura, Y., et al. (2004) · Environmental Health Perspectives · doi:10.1289/ehp.6864 · Cited by 460
Li, Y., Shan, Z., Teng, W., Yu, X., Li, Y., Fan, C., Teng, X., Guo, R., Hong, W., Li, J., et al. (2009) · Clinical Endocrinology · doi:10.1111/j.1365-2265.2009.03743.x · Cited by 449
Vermiglio, F., Presti, V. P. L., Moleti, M., SIDOTI, M., Tortorella, G., Scaffidi, G., Castagna, M. G., Mattina, F., Violi, M. A., Crisà, A., et al. (2004) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2004-0571 · Cited by 440
de Escobar, G. M. (2000) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.85.11.3975 · Cited by 436
General Background on the Hypothalamic-Pituitary-Thyroid (HPT) Axis
Zoeller, R. T., Tan, S. W., & Tyl, R. W. (2007) · Critical Reviews in Toxicology · doi:10.1080/10408440601123446 · Cited by 422
Olsen, G. W., Church, T. R., Miller, J. P., Burris, J. M., Hansen, K. J., Lundberg, J. K., Armitage, J. B., Herron, R., Medhdizadehkashi, Z., Nobiletti, J. B., et al. (2003) · Environmental Health Perspectives · doi:10.1289/ehp.6316 · Cited by 401
Weiss, J. M., Andersson, P. L., Lamoree, M. H., Leonards, P. E. G., van Leeuwen, S. P. J., & Hamers, T. (2009) · Toxicological Sciences · doi:10.1093/toxsci/kfp055 · Cited by 373
Olsen, G. W., Burris, J. M., Burlew, M., & Mandel, J. H. (2003) · Journal of Occupational and Environmental Medicine · doi:10.1097/01.jom.0000052958.59271.10 · Cited by 362
Emmett, E. A., Shofer, F. S., Zhang, H., Freeman, D. W., Desai, C. S., & Shaw, L. M. J. (2006) · Journal of Occupational and Environmental Medicine · doi:10.1097/01.jom.0000232486.07658.74 · Cited by 357
Surks, M. I., & Sievert, R. (1995) · New England Journal of Medicine · doi:10.1056/nejm199512213332507 · Cited by 349
Hypothyroidism Complicating Pregnancy
Buckshee, K., Kriplani, A., Kapil, A., Bhargava, V. L., & Takkar, D. (2008) · Australian and New Zealand Journal of Obstetrics and Gynaecology · doi:10.1111/j.1479-828x.1992.tb01956.x · Cited by 319
Luebker, D. J., York, R. G., Hansen, K. J., Moore, J. A., & Butenhoff, J. L. (2005) · Toxicology · doi:10.1016/j.tox.2005.07.019 · Cited by 314
Olsen, G. W., & Zobel, L. R. (2007) · International Archives of Occupational and Environmental Health · doi:10.1007/s00420-007-0213-0 · Cited by 307
Kuklenyik, Z., Reich, J. A., Tully, J. S., Needham, L. L., & Calafat, A. M. (2004) · Environmental Science & Technology · doi:10.1021/es040332u · Cited by 297
Perspectives in the Study of Thyroid Hormone Action on Brain Development and Function
Bernal, J., Guadaño‐Ferraz, A., & Morte, B. (2003) · Thyroid · doi:10.1089/105072503770867174 · Cited by 292
Thyroid Function and Perfluoroalkyl Acids in Children Living Near a Chemical Plant
López-Espinosa, M.-J., Mondal, D., Armstrong, B., Bloom, M. S., & Fletcher, T. (2012) · Environmental Health Perspectives · doi:10.1289/ehp.1104370 · Cited by 263
Toxicity of Ammonium Perfluorooctanoate in Male Cynomolgus Monkeys after Oral Dosing for 6 Months
Butenhoff, J. L. (2002) · Toxicological Sciences · doi:10.1093/toxsci/69.1.244 · Cited by 259
Hypothyroidism complicating pregnancy.
Davis, L. E., Leveno, K. J., & Cunningham, F. G. (1988) · PubMed · Cited by 255
Kim, S., Choi, K., Ji, K., Seo, J., Kho, Y., Park, J., Kim, S., Park, S., Hwang, I., Jeon, J.-K., et al. (2011) · Environmental Science & Technology · doi:10.1021/es202408a · Cited by 250
Neonatal Effects of Maternal Hypothyroxinemia During Early Pregnancy
Kooistra, L., Crawford, S. G., van Baar, A. L., Brouwers, E. P. M., & Pop, V. J. M. (2006) · PEDIATRICS · doi:10.1542/peds.2005-0227 · Cited by 239
Chang, S., Thibodeaux, J. R., Eastvold, M. L., Ehresman, D. J., Bjork, J. A., Froehlich, J. W., Lau, C. S., Singh, R. J., Wallace, K. B., & Butenhoff, J. L. (2007) · Toxicology · doi:10.1016/j.tox.2007.10.014 · Cited by 209
Thyroid Function and Plasma Concentrations of Polyhalogenated Compounds in Inuit Adults
Dallaire, R., Dewailly, É., Pereg, D., Déry, S., & Ayotte, P. (2009) · Environmental Health Perspectives · doi:10.1289/ehp.0900633 · Cited by 206
What Happens to the Normal Thyroid During Pregnancy?
Glinoer, D. (1999) · Thyroid · doi:10.1089/thy.1999.9.631 · Cited by 199
Bellinger, D. C. (2011) · Environmental Health Perspectives · doi:10.1289/ehp.1104170 · Cited by 197
Effects of perfluorooctane sulfonate on rat thyroid hormone biosynthesis and metabolism
Yu, W., Liu, W., & Jin, Y. (2008) · Environmental Toxicology and Chemistry · doi:10.1897/08-345.1 · Cited by 195
Perfluorinated chemicals in relation to other persistent organic pollutants in human blood
Kärrman, A., van Bavel, B., Järnberg, U., Hardell, L., & Lindström, G. (2006) · Chemosphere · doi:10.1016/j.chemosphere.2005.11.040 · Cited by 191
Haines, D. A., & Murray, J. (2011) · International Journal of Hygiene and Environmental Health · doi:10.1016/j.ijheh.2011.09.008 · Cited by 165
Wang, Y., Rogan, W. J., Chen, P.-C., Lien, G.-W., Chen, H.-Y., Tseng, Y.-C., Longnecker, M. P., & Wang, S.-L. (2014) · Environmental Health Perspectives · doi:10.1289/ehp.1306925 · Cited by 162
Thyroxine Levels During Pregnancy in Healthy Women and Early Child Neurodevelopment
Júlvez, J., Álvarez‐Pedrerol, M., Rebagliato, M., Murcia, M., Forns, J., García‐Esteban, R., Lertxundi, N., Espada, M., Tardón, A., Galán, I. R., et al. (2012) · Epidemiology · doi:10.1097/ede.0b013e318276ccd3 · Cited by 150
Drugs affecting thyroid function
Barbesino, G. (2010) · Thyroid · doi:10.1089/thy.2010.1635 · Cited by 146
Åsvold, B. O., Bjøro, T., & VATTEN, L. J. (2010) · European Journal of Endocrinology · doi:10.1530/eje-10-0705 · Cited by 145
Ji, K., Kim, S., Kho, Y., Paek, D., Sakong, J., Ha, J., Kim, S., & Choi, K. (2012) · Environment International · doi:10.1016/j.envint.2012.03.007 · Cited by 140
Maternal hypothyroxinemia and effects on cognitive functioning in childhood: how and why?
Henrichs, J., Ghassabian, A., Peeters, R. P., & Tiemeier, H. W. (2013) · Clinical Endocrinology · doi:10.1111/cen.12227 · Cited by 138
Thyroid hormone testing by tandem mass spectrometry
Soldin, O. P., & Soldin, S. J. (2010) · Clinical Biochemistry · doi:10.1016/j.clinbiochem.2010.07.020 · Cited by 128
Pregnancy Outcomes in Women With Thyroid Peroxidase Antibodies
Abbassi-Ghanavati, M., Casey, B. M., Spong, C. Y., McIntire, D. D., Halvorson, L. M., & Cunningham, F. G. (2010) · Obstetrics and Gynecology · doi:10.1097/aog.0b013e3181e904e5 · Cited by 120
Binding of PFOS to Serum Albumin and DNA: Insight into the Molecular Toxicity of Perfluorochemicals
Zhang, X., Chen, L., Fei, X.-C., Ma, Y.-S., & Gao, H.-W. (2009) · BMC Molecular Biology · doi:10.1186/1471-2199-10-16 · Cited by 119
Changes in thyroid peroxidase activity in response to various chemicals
Song, M., Kim, Y., Park, Y., & Ryu, J. (2012) · Journal of Environmental Monitoring · doi:10.1039/c2em30106g · Cited by 101
Guillaume, J., Schussler, G. C., Goldman, J. M., WASSEL, P., & BACH, L. (1985) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jcem-60-4-678 · Cited by 99
Yu, W., Liu, W., Jin, Y., Liu, X., Wang, F.-Q., Li, L., & Nakayama, S. F. (2009) · Environmental Science & Technology · doi:10.1021/es901602d · Cited by 97
Perfluorocarbon exposure, gender and thyroid function in the C8 Health Project
S. Knox, S., Jackson, T., J. Frisbee, S., Javins, B., & M. Ducatman, A. (2011) · The Journal of Toxicological Sciences · doi:10.2131/jts.36.403 · Cited by 95
Carrier-Mediated Thyroid Hormone Transport into Placenta by Placental Transthyretin
Landers, K., McKinnon, B. D., Li, H., Subramaniam, V. N., Mortimer, R. H., & Richard, K. (2009) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2009-0048 · Cited by 92
Exploratory assessment of perfluorinated compounds and human thyroid function
Bloom, M. S., Kannan, K., Spliethoff, H. M., Lin, T., Aldous, K. M., & Vena, J. E. (2009) · Physiology & Behavior · doi:10.1016/j.physbeh.2009.02.005 · Cited by 88
Lockwood, C. M., Grenache, D. G., & Gronowski, A. M. (2009) · Thyroid · doi:10.1089/thy.2009.0079 · Cited by 87
Chang, S., Thibodeaux, J. R., Eastvold, M. L., Ehresman, D. J., Bjork, J. A., Froehlich, J. W., Lau, C. S., Singh, R. J., Wallace, K. B., & Butenhoff, J. L. (2007) · Toxicology · doi:10.1016/j.tox.2007.01.020 · Cited by 70
Hypothyroxinemia and Pregnancy
Negro, R., Soldin, O. P., Obregón, M.-J., & Stagnaro‐Green, A. (2011) · Endocrine Practice · doi:10.4158/ep10309.ra · Cited by 69
Lepage, N., Chitayat, D. A., Kingdom, J. C., & Huang, T. (2003) · American Journal of Obstetrics and Gynecology · doi:10.1067/mob.2003.278 · Cited by 67
Wang, Y., Starling, A. P., Haug, L. S., Eggesbø, M. Å., Becher, G., Thomsen, C., Travlos, G. S., King, D., Hoppin, J. A., Rogan, W. J., et al. (2013) · Environmental Health · doi:10.1186/1476-069x-12-76 · Cited by 64
Perfluorinated acids and hypothyroxinemia in pregnant women
Chan, E., Burstyn, I., Cherry, N., Bamforth, F. J., & Martin, J. W. (2011) · Environmental Research · doi:10.1016/j.envres.2011.01.011 · Cited by 63
Self-citationHandbook of diagnostic biochemistry and hematology in normal pregnancy
Lockitch, G. (1993) · Cited by 56
Jain, R. B. (2013) · Journal of Toxicology and Environmental Health · doi:10.1080/15287394.2013.771547 · Cited by 52
Perfluorooctane sulfonate increased hepatic expression of OAPT2 and MRP2 in rats
Yu, W., Liu, W., Liu, L., & Jin, Y. (2010) · Archives of Toxicology · doi:10.1007/s00204-010-0613-x · Cited by 47
Webster, G. M., Teschke, K., & Janssen, P. A. (2011) · Maternal and Child Health Journal · doi:10.1007/s10995-010-0739-8 · Cited by 43
Self-citationTo Treat or Not to Treat Euthyroid Autoimmune Disorder during Pregnancy?
Debiève, F., Dulière, S., Bernard, P., Hubinont, C., Nayer, P. D., & Daumerie, C. (2008) · Gynecologic and Obstetric Investigation · doi:10.1159/000185689 · Cited by 24
Flagged first, then by citations
1 of the 72 references couldn’t be matched to a known paper.
Research works printed but not linked: 1
- Jarrige, 2006, Reference intervals of maternal free thyroxine (FT4) at the second and third trimesters of pregnancy using Beckman Colter׳s access free T4 assay, Endocr. Abstr., 11, 818
Cited by
Sorted by citations
Fenton, S. E., Ducatman, A., Boobis, A., DeWitt, J. C., Lau, C., Ng, C., Smith, J. S., & Roberts, S. M. (2020) · Environmental Toxicology and Chemistry · doi:10.1002/etc.4890 · Cited by 2,445
Risk to human health related to the presence of perfluoroalkyl substances in food
Panel), E. P. O. C. I. T. F. C. (. C., Schrenk, D., Bignami, M., Bodin, L., Chipman, J. K., del Mazo, J., Grasl‐Kraupp, B., Hogstrand, C., Hoogenboom, L. (., Leblanc, J., et al. (2020) · EFSA Journal · doi:10.2903/j.efsa.2020.6223 · Cited by 989
Emerging contaminants of high concern for the environment: Current trends and future research
Khan, S., Naushad, M., Govarthanan, M., Iqbal, J., & Alfadul, S. M. (2021) · Environmental Research · doi:10.1016/j.envres.2021.112609 · Cited by 740
Emerging contaminants of high concern and their enzyme-assisted biodegradation – A review
Bilal, M., Adeel, M., Rasheed, T., Zhao, Y., & Iqbal, H. M. N. (2019) · Environment International · doi:10.1016/j.envint.2019.01.011 · Cited by 499
(CONTAM), E. P. O. C. I. T. F. C., Knutsen, H. K., Alexander, J., Barregård, L., Bignami, M., Brüschweiler, B. J., Ceccatelli, S., Cottrill, B., Dinovi, M., Edler, L., et al. (2018) · EFSA Journal · doi:10.2903/j.efsa.2018.5194 · Cited by 549
Metadata
- Authors
- Webster, G. M., Venners, S. A., Mattman, A., & Martin, J. W.
- Affiliations
- Simon Fraser University (CA)
- BC Children's Hospital (CA)
- University of Alberta (CA)
- Corresponding author
- Webster, Glenys M.
- ORCID
- Martin, Jonathan W.
- Venue
- Environmental Research
- Publisher
- Elsevier BV
- Published
- 2014-08
- Volume
- 133
- Pages
- 338-347
- ISSN
- 0013-9351 (ISSN-L)
- OpenAlex
- W2018354811
- Cited by
- 145
- References
- 72
- Citations by year
- 2026: 9 · 2025: 10 · 2024: 15 · 2023: 11 · 2022: 16 · 2021: 13 · 2020: 21 · 2019: 13 · 2018: 10 · 2017: 6 · 2016: 12 · 2015: 8 · 2014: 1
- FWCI
- 6.84
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Environmental Research (publishedVersion)
- PubMed (publishedVersion)
- Funders
- University of British Columbia
- Topics
- Physical Sciences › Environmental Science › Environmental Chemistry › Per- and polyfluoroalkyl substances research
- Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Thyroid Disorders and Treatments
- Physical Sciences › Environmental Science › Health, Toxicology and Mutagenesis › Effects and risks of endocrine disrupting chemicals
- Keywords
- perfluoroalkyl acids, PFASs, maternal thyroid hormones, thyroid-stimulating hormone, free thyroxine, thyroid peroxidase antibodies, Hashimoto's thyroiditis, autoimmune hypothyroidism, perfluorooctanoic acid, PFOS, PFHxS, perfluorononanoate, early pregnancy, fetal brain development
- MeSH terms
- Adolescent, Adult, Caprylates, Environmental Pollutants, Female, Fluorocarbons, Humans, Pregnancy, Pregnancy Trimester, Second, Sulfonic Acids, Thyrotropin, Thyroxine, Cohort Studies, Alkanesulfonic Acids, Young Adult
About these checks
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.
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 ›
Are you an author, or do you see a problem with this page? Request a review
