[Note: Perfluorinated chemicals are widely used for their stain/water repelling, heat stable, nonstick qualities in clothing, furniture, carpets, floor waxes & cleaners, cookware and paper coatings, etc. Fecundity is measure of ease in becoming pregnant; fertility.]
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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 [fertility] in humans.
Plasma levels of PFOS and PFOA were measured at weeks 4 to 14 of pregnancy among 1,240 women from the Danish National Birth Cohort recruited from 1996 to 2002.
For this pregnancy, women reported time to pregnancy (TTP) in five categories (less than 1; 1–2; 3–5; 6–12; and more than 12 months).
Infertility was defined as having a TTP of more than 12 months or received infertility treatment to establish this pregnancy.
Longer time to pregnancy 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% to 134%, and 60% to 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. [Note: An FOR of 1.00 would mean no difference between two groups. An OR of 0.70 means women in this quartile were 30% less fecund on average than those in the lowest exposure 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.
Source: Human Reproduction, Jan 28, 2009. PMID: 19176540, by Fei C, McLaughlin JK, Lipworth L, Olsen J. Department of Epidemiology, School of Public Health, UCLA; International Epidemiology Institute, Rockville, Maryland; Vanderbilt University Medical Center, Vanderbilt-Ingram Cancer Center, Nashville, Tennessee, USA; Institute of Public Health, University of Aarhus, Denmark. [E-mail: email@example.com]