Environmental exposures and fecundability: The Norwegian Mother, Father, and Child Cohort study

Previous studies have linked certain environmental exposures to reduced fecundability, influencing exposure recommendations. We continue to encounter numerous environmental exposures in our everyday lives, and further evidence is needed regarding their effects on fecundability. We evaluated associations between various self-reported environmental exposures and fecundability, measured as time to pregnancy, in 64,942 women and 53,219 men participating in the Norwegian Mother, Father, and Child Cohort study (MoBa). Women reported on 17, and men on 19, environmental exposures, including heavy metals, pesticides, paints, and radiation. Fecundability ratios (FR) were estimated using log-binomial regression, comparing likelihood of conception during a given menstrual cycle between exposed versus unexposed participants. About 50 % of women and 75 % of men reported minimum one environmental exposure. Exposure to any pesticide (FR 0.94 [95 % CI 0.91-0.98]), and frequent exposure to photographic chemicals (FR 0.84 [95 % CI: 0.73-0.96]), was associated with decreased fecundability in women. We also observed a tendency of a slightly higher fecundability among women and men exposed to disinfectants (FR 1.02 [95 % CI: 1.00-1.04] and 1.03 [95 % CI: 1.00-1.06], respectively). Our results suggests that exposure to pesticides and photographic chemicals could affect women's fecundability.