Urinary bisphenol A, phthalates, and couple fecundity: the Longitudinal Investigation of Fertility and the Environment (LIFE) Study.

To assess the relationship between environmental chemicals and couple fecundity or time to pregnancy (TTP). Prospective cohort. Communities of targeted populations with reported exposure. 501 couples recruited upon discontinuing contraception to become pregnant, 2005-2009. None. Fecundability odds ratios (FORs) and 95% confidence intervals (CIs) estimated for each partner's chemical concentrations adjusted for age, body mass index, cotinine, creatinine, and research site while accounting for time off contraception. Couples completed interviews and anthropometric assessments and provided the urine specimens for quantification of bisphenol A (BPA) and 14 phthalate metabolites, which were measured using high-performance liquid chromatography with electrospray triple-quadrupole mass spectrometer. Women recorded menstruation and pregnancy test results in daily journals. Couples were evaluated until a positive human-chorionic gonadotropin pregnancy test or 12 cycles without pregnancy. Neither female nor male BPA concentration was associated with TTP (FOR 0.98; 95% CI, 0.86, 1.13 and FOR 1.04; 95% CI, 0.91, 1.18, respectively). Men's urinary concentrations of monomethyl, mono-n-butyl, and monobenzyl phthalates were associated with a longer TTP (FOR 0.80; 95% CI, 0.70, 0.93; FOR 0.82, 95% CI, 0.70, 0.97; and FOR 0.77, 95% CI, 0.65 0.92, respectively). Select male but not female phthalate exposures were associated with an approximately 20% reduction in fecundity, underscoring the importance of assessing both partners' exposure to minimize erroneous conclusions.