title: Perfluorinated acids and hypothyroxinemia in pregnant women.
abstract: Perfluorinated acids (PFAs) are prominent and widespread contaminants of human blood. In animal studies there is evidence that suggests certain PFAs can disrupt thyroid hormone homeostasis. A commonly reported condition in exposed animals is hypothyroxinemia, whereby serum free thyroxine (fT4) is decreased despite normal thyroid stimulating hormone (TSH) concentrations. We designed an individually matched case-control study to investigate whether exposure to perfluorooctanoate (PFOA), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) was associated with hypothyroxinemia in pregnant women from Edmonton, Alberta, Canada, in 2005-2006, who underwent a "triple screen" blood test at 15-20 weeks gestation as part of ante-natal care. Thyroid hormones, fT4 and TSH, were measured in serum from 974 women, and from these we measured PFAs in the sera of 96 hypothyroxinemic cases (normal TSH, the lowest 10th percentile of fT4) and 175 controls (normal TSH, fT4 between the 50th and 90th percentiles) matched on age and referring physician. Analyses by conditional logistic regression indicated that the concentrations of PFAs in this population were not associated with hypothyroxinemia among pregnant women. The current findings do not support a causal link between PFA exposure and maternal hypothyroxinemia in the studied population.
authors.affiliation: Department of Public Health Sciences, School of Public Health, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Emily
authors.initials: E
authors.lastname: Chan
authors.forename: Igor
authors.initials: I
authors.lastname: Burstyn
authors.forename: Nicola
authors.initials: N
authors.lastname: Cherry
authors.forename: Fiona
authors.initials: F
authors.lastname: Bamforth
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Martin
mesh_terms: D000328:Adult; D017738:Alkanesulfonic Acids / Q000097:blood; D002210:Caprylates / Q000097:blood / Q000633:toxicity; D052244:Endocrine Disruptors / Q000097:blood* / Q000633:toxicity; D004785:Environmental Pollutants / Q000097:blood* / Q000633:toxicity; D005260:Female; D005466:Fluorocarbons / Q000097:blood* / Q000633:toxicity; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000453:epidemiology*; D018811:Maternal Exposure / Q000706:statistics & numerical data; D008875:Middle Aged; D011247:Pregnancy; D013451:Sulfonic Acids / Q000097:blood; D013974:Thyroxine / Q000097:blood*; D055815:Young Adult
chemical_list: D017738:Alkanesulfonic Acids; D002210:Caprylates; D052244:Endocrine Disruptors; D004785:Environmental Pollutants; D005466:Fluorocarbons; D013451:Sulfonic Acids; C471071:perfluorohexanesulfonic acid; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid; D013974:Thyroxine