Effects of perfluorinated chemicals on thyroid function, markers of ovarian reserve, and natural fertility

•PFC levels in our cohort were consistent with levels seen in the general US population of reproductive age women.•There was positive correlation between PFCs measured in this study.•Although PFC levels were correlated with thyroid hormone levels, there was not a strong nor a significant association with ovarian reserve.•In our cohort, fecundability was not associated with serum PFC levels. Perfluorinated chemicals (PFCs) can act as endocrine-disrupting chemicals, but there has been limited study of their effects on ovarian reserve or fecundability. 99 women, 30–44 years old, without infertility were followed until pregnancy. Initially, serum was evaluated for Antimullerian hormone (AMH), thyroid hormones: thyroid stimulating hormone (TSH), thyroxine (T4), free thyroxine (fT4), and triiodothyronine (T3), and PFCs: perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluorohexanesulfonic acid (PFHxS). Bivariate analyses assessed the relationship between thyroid hormones, AMH, and PFCs. Fecundability ratios (FR) were determined for each PFC using a discrete time-varying Cox model and a day-specific probability model. PFC levels were positively correlated with each other (r 0.24–0.90), but there was no correlation with TSH (r 0.02–0.15) or AMH (r −0.01 to −0.15). FR point estimates for each PFC were neither strong nor statistically significant. Although increased exposure to PFCs correlates with thyroid hormone levels, there is no significant association with fecundability or ovarian reserve.