Periconceptional exposure to bisphenol-A and fecundability among couples trying to conceive in a prospective, preconception cohort

Abstract

Background: Bisphenol-A (BPA) is an endocrine disrupting chemical with nearly ubiquitous exposure. BPA caused reproductive dysfunction in animal models, but data in humans are limited. Objective: Examine couple urinary BPA concentration and fecundability. Methods: A prospective, pre-conception cohort of heterosexual couples (women 18–35, men 18–40) without known infertility or subfertility were recruited, and women observed cervical mucus to identify an estimated day of ovulation and fertile window. Couples collected daily first-morning urine samples during the fertile window and women continued daily collection until the onset of menses or estimated day of ovulation +18 days. Cox proportional hazards models for discrete survival time, adjusting for left truncation for time trying before enrollment, were performed to assess time-varying BPA and fecundability. Models were adjusted for woman’s age and education level, household income, women and men’s BMI, and parity. Fecundability odds ratios (FOR) <1.0 indicate reduced fecundity and longer time to pregnancy, whereas FORs>1.0 indicate enhanced fecundity and shorter time to pregnancy. Results: Women collected mean 16.7±5.2 and men collected mean 5.1±2.1 urine samples per cycle. Among 183 couples, 126 conceived during the study, and 16 early pregnancy losses were observed. There was no association between periconceptional BPA exposure and fecundability either among all pregnancies (FOR 0.995, 95% CI: 0.962, 1.029) or when restricting to live births (FOR 1.002, 95% CI: 0.969, 1.036). Discussion: In this sample of 183 couples, no association between BPA and fecundability was observed. Strengths of this study were the prospective biospecimen collection during the fertile window and serial, daily urine collection to support robust BPA exposure assessment for both men and women.