Organochlorine pesticides, polychlorinated biphenyls, seafood consumption, and time-to-pregnancy.

BACKGROUND

People in developed countries are widely exposed to low levels of organochlorine pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). Seafood is a major contributor to PCB exposure. Toxicity of those various pollutants to reproductive and endocrine functions raises questions about possible effects on fertility. We explored whether serum levels of these pollutants and seafood consumption were associated with the fertility of couples enrolled in a French birth cohort (PELAGIE).

METHODS

Time-to-pregnancy was investigated in 3,421 pregnant women by asking how many months they had taken to conceive. Levels of 14 organochlorine pesticides, 12 PCBs, and 10 PBDE compounds were measured in cord blood serum from a random subcohort (n = 394). Mercury concentrations measured in maternal hair were considered as a potential coexposure. Fecundability odds ratios (ORs) were estimated from multivariate discrete-time Cox proportional hazard models.

RESULTS

Shellfish consumption was associated with longer time-to-pregnancy (fecundability OR ≥twice/week vs. <twice/month = 0.71 [95% confidence interval = 0.60-0.83]), but fish consumption was not. Time-to-pregnancy increased with increasing serum levels for most of the compounds studied (for total PCBs >0.410 µg/L vs. <0.266 µg/L, fecundability OR = 0.46 [0.32-0.66]). In multiple sensitivity analyses, reduced fecundability was most consistently associated with shellfish consumption, p,p'-DDE, total PCBs, PCB153, and PCB187. Models that simultaneously included multiple coexposure factors led to similar conclusions.

CONCLUSIONS

Our findings were robust in sensitivity analyses, including analysis restricted to primiparous women. These results suggest that PCBs, p,p'-DDE, and other shellfish contaminants may impair human fertility.