Association between urinary paraben concentrations and gestational weight gain during pregnancy

Parabens, a group of endocrine-disrupting chemicals, have been associated with obesity in previous studies. However, there is a paucity of literature regarding the effects of paraben exposures on gestational weight gain (GWG), a considerable predictor of obesity risk in both mothers and offspring later in life. The aim of the present study was to evaluate the associations between urinary paraben concentrations and GWG during the three trimesters of pregnancy. We collected urine samples from 613 pregnant women during the first, second, and third trimesters of their pregnancies between 2014 and 2015 in Wuhan, China. The urine concentrations of five parabens, including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), butylparaben, and benzylparaben, were measured. Gestational weight in each trimester and prepregnancy weight were used to calculate trimester GWG. Linear mixed models were used to evaluate the trimester-specific and overall associations between paraben exposures and GWG rate (trimester GWG divided by the gestational week of the weight measurement, kg/week). We performed stratified analysis to further explore the potential effect modification by prepregnancy BMI. In the trimester-specific association analyses, the first-trimester concentrations MeP, EtP, PrP, and ∑parabens (sum of all five parabens's molar concentrations) were associated with an increased first-trimester GWG rate, and these associations were stronger than those of the second or third trimesters. The overall association analysis showed that increased trimester GWG rates were associated with the combined effects of exposure to MeP, PrP, or ∑parabens during all three trimesters. Stratified analysis showed that higher paraben exposures were associated with higher trimester GWG rates among overweight/obese women that among normal-weight or underweight women. Our results showed that paraben exposures were positively associated with trimester GWG rate during pregnancy, especially during the first trimester. Replicated research in populations exposed to higher paraben levels is needed in the future.