Chlordecone exposure in women and time to pregnancy: the Timoun cohort study in Guadeloupe, French West Indies

Chlordecone is a persistent organochlorine insecticide that was widely used to control banana root borer in the French West Indies until 1993. Animal studies have reported an impact of chlordecone exposure on female fertility, but no data are available for humans. Here, we investigated the association between chlordecone exposure in women and time to pregnancy (TTP). We included 668 pregnant women from the Timoun mother-child cohort study performed in Guadeloupe between 2004 and 2007. TTP was measured with a questionnaire at the inclusion visit. Chlordecone concentrations in maternal blood samples were determined at the time of delivery. A discrete-time Cox model was used to estimate fecundability odds ratios (fOR) and their 95% confidence intervals (95% CIs), with adjustment for potential confounders. Sensitivity analyses were performed by modifying the study population and censoring criteria. Chlordecone was detected in 91% of the study population, with a median concentration of 0.3 µg/L (IQR: 0.1–0.7). The third and fourth quartiles of chlordecone exposure were associated with significantly lower fecundability (fORa [95% CI] = 0.76 [0.58, 0.99]; fORa [95% CI] = 0.72 [0.55, 0.95], respectively). A significant dose-dependent relationship was observed between chlordecone exposure and TTP (p-trend = 0.01). Similar results were observed in all sensitivity analyses except that for primiparous women. Our study supports the hypothesis that chlordecone affects the fertility of women and is therefore a public health concern in widely contaminated areas, such as the French West Indies. • Chlordecone is an organochlorine pesticide used in the French West Indies until 1993. • Chlordecone affects female fertility in animals, but this has not yet been studied in humans. • Chlordecone was detected in 91% of blood samples from pregnant women in the Timoun cohort. • Chlordecone exposure is associated with a dose-response trend towards longer time to pregnancy in women.