Prenatal Exposure to Phenols and Growth in Boys

Background: Phenols interact with nuclear receptors implicated in growth and adipogenesis regulation. Only a few studies have explored their effects on growth in humans. Objectives: We studied the associations of maternal exposure to phenols during pregnancy with prenatal and postnatal growth of male newborns. Methods: Within a cohort of women recruited during pregnancy, we selected 520 mother-son pairs and quantified 9 phenols in spot urine samples collected during pregnancy. We used ultrasonography during pregnancy, together with birth measurements, to assess fetal growth. We modeled individual postnatal growth trajectories from repeated measures of weight and height in the first 3 years of life. Results: Triclosan concentration was negatively associated with growth parameters measured at the third ultrasound examination but not earlier in pregnancy. At birth, this phenol tended to be negatively associated with head circumference (-1.2 mm for an interquartile range [IQR] increase in ln-transformed triclosan concentration [95% confidence interval = -2.6 to 0.3]) but not with weight or height. Parabens were positively associated with weight at birth. This positive association remained for 3 years for methylparaben (beta = 193 g [-4 to 389]) for an IQR increase in ln-transformed concentrations. Conclusion: We relied on only 1 spot urine sample to assess exposure; because of the high variability in phenol urinary concentrations reported during pregnancy, using only 1 sample may result in exposure misclassification, in particular for bisphenol A. Our study suggested associations between prenatal exposure to parabens and triclosan and prenatal or early postnatal growth.