Prenatal Exposure to Select Phthalates and Phenols and Associations with Fetal and Placental Weight among Male Births in the EDEN Cohort (France)

BACKGROUND: The placenta performs crucial physiological functions to ensure normal fetal development. Few epidemiological studies investigated placental weight sensitivity to phthalates and phenols. OBJECTIVE: Our goal was to explore whether maternal exposure to select phthalates and phenols is associated with changes in placental weight at birth and in placental to birth weight ratio (PFR). METHODS: Placental weight and birth weight were available for 473 mother son pairs in the EDEN (Etude des Determinants pre et postnatals du developpement et de la sante de l' Enfant) cohort for whom 9 phenols (4 parabens, 2 dichlorophenols, triclosan, benzophenone-3, bisphenol A) and 11 phthalate metabolites were measured in spot urine samples collected between weeks 23 and 29 of gestation. We used adjusted Elastic Net penalized regression models (ENET) to select biomarkers associated with placental weight, birth weight and PER. Unpenalized effect estimates were then obtained by fitting linear regression models simultaneously adjusted for the ENET-selected biomarkers and a priori chosen confounders. RESULTS: The multipollutant ENET model for placental weight retained four biomarkers: triclosan and monocarboxy-isononyl phthalate (MCNP), which were negatively associated with placental weight, and benzophenone-3 and the sum of parabens, which were positively associated with this outcome. The ENET model for PFR retained two phthalate metabolites [MCNP and monocarboxy-isooctyl phthalate (MCOP)], which were negatively associated with this outcome. DISCUSSION: The positive association between the sum of parabens and placental weight was consistent with results of a previous study among 49 male births. Our results provide preliminary evidence of possible associations between other compounds such as triclosan, benzophenone-3, MCNP, and MCOP and both placental weight and PFR. These associations were not reported in previous studies and should be seen as hypothesis generating. Studies relying on repeated assessments of exposure in prospective mother child cohorts are needed to substantiate the plausibility of the hypotheses generated by our results.