Association between urinary parabens and gestational diabetes mellitus across prepregnancy body mass index categories

Increasing evidence suggests a potential role of endocrine disrupting chemicals (EDCs) in inducing gestational diabetes mellitus (GDM). However, as far as we know, no study has examined the associations between GDM and exposure to parabens, a kind of EDCs. In this study, we explored the association between urinary parabens of pregnant women and GDM and studied the modification effect of prepregnancy body mass index (BMI). Urine samples were collected from 696 pregnant women and parabens were measured, including four alkyl side chain substituted para-hydroxybenzoic acid ester, substituents varying from methyl to butyl (abbreviates as MeP, EtP, PrP and BuP), and benzyl substituted para-hydroxybenzoic acid ester (BzP). Logistic regression models adjusting for potential confounders were used to study the association of parabens and GDM in the overall population, and further stratified analysis by prepregnancy BMI categories was also performed. The detection rates for the five parabens in the urine samples were 97.70% (MeP), 71.26% (EtP), 96.55% (PrP), 15.80% (BuP) and 2.73% (BzP). No significant association was found between parabens and GDM among the overall population. However, significant non-linear associations of PrP and the summed estrogenic activity of parabens with GDM were found in the stratified analysis by prepregnancy BMI in the overweight/obese population, with adjusted odds ratios (aORs) of 3.47 (95% CI: 1.28, 9.42) and 2.87 (95% CI: 1.07, 7.73) for GDM in the second tertile of urinary PrP and the summed estrogen activity, respectively, when compared to the first tertile. Although no statistically significant association between parabens and GDM was found in the overall population, we found that among the overweight/obese pregnant women, who represent a subgroup more prone to GDM, moderately higher levels of PrP and summed estrogenic activity of parabens were significantly associated with an increasing GDM prevalence.