title: Maternal levels of perfluorinated chemicals and subfecundity.
abstract: BACKGROUND
  Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) are ubiquitous man-made compounds that are possible hormonal disruptors. We examined whether exposure to these compounds may decrease fecundity in humans.
  
  
  METHODS
  Plasma levels of PFOS and PFOA were measured at weeks 4-14 of pregnancy among 1240 women from the Danish National Birth Cohort recruited from 1996 to 2002. For this pregnancy, women reported time to pregnancy (TTP) in five categories (<1, 1-2, 3-5, 6-12 and >12 months). Infertility was defined as having a TTP of >12 months or received infertility treatment to establish this pregnancy.
  
  
  RESULTS
  Longer TTP was associated with higher maternal levels of PFOA and PFOS (P < 0.001). Compared with women in the lowest exposure quartile, the adjusted odds of infertility increased by 70-134 and 60-154% among women in the higher three quartiles of PFOS and PFOA, respectively. Fecundity odds ratios (FORs) were also estimated using Cox discrete-time models. The adjusted FORs were virtually identical for women in the three highest exposure groups of PFOS (FOR = 0.70, 0.67 and 0.74, respectively) compared with the lowest quartile. A linear-like trend was observed for PFOA (FOR = 0.72, 0.73 and 0.60 for three highest quartiles versus lowest quartile). When all quartiles were included in a likelihood ratio test, the trends were significant for PFOS and PFOA (P = 0.002 and P < 0.001, respectively).
  
  
  CONCLUSIONS
  These findings suggest that PFOA and PFOS exposure at plasma levels seen in the general population may reduce fecundity; such exposure levels are common in developed countries.
authors.affiliation: Department of Epidemiology, School of Public Health, University of California - Los Angeles, PO Box 951772, 71-254 CHS, 650 Charles E. Young Drive South, Los Angeles, CA 90095-1772, USA. cfei@ucla.edu
authors.forename: Chunyuan
authors.initials: C
authors.lastname: Fei
authors.forename: Joseph K
authors.initials: JK
authors.lastname: McLaughlin
authors.forename: Loren
authors.initials: L
authors.lastname: Lipworth
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
mesh_terms: D000328:Adult; D017738:Alkanesulfonic Acids / Q000097:blood* / Q000633:toxicity; D002210:Caprylates / Q000097:blood* / Q000633:toxicity; D015331:Cohort Studies; D004785:Environmental Pollutants / Q000097:blood*; D005260:Female; D005298:Fertility / Q000187:drug effects*; D005466:Fluorocarbons / Q000097:blood* / Q000633:toxicity; D006801:Humans; D018811:Maternal Exposure; D011247:Pregnancy; D013997:Time Factors
chemical_list: D017738:Alkanesulfonic Acids; D002210:Caprylates; D004785:Environmental Pollutants; D005466:Fluorocarbons; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid