Exposure to phthalates in early pregnancy and the risk of fetal growth restriction: a nested case–control study in a Zhuang Chinese population

Abstract

Phthalates (PAEs) are common endocrine disrupting chemicals (EDCs) that disrupt fetal development. The present study aimed to evaluate the effects of single and coexposure to phthalates in early pregnancy on fetal growth restriction (FGR) by a nested case-control study based on the Guangxi Zhuang Birth Cohort (GZBC). Maternal serum concentrations of seven phthalates in 97 neonates with FGR and 291 matched controls were detected through gas chromatography-mass spectrometry (GC-MS). The associations between phthalates and FGR were analyzed using multiple logistic regression, weight quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models. We found that exposures to butyl-benzyl phthalate (BBP, ORadj = 1.849, 95% CI: 1.080-3.177, Padj = 0.025, Ptrend = 0.046), di (2-ethyl-hexyl) phthalate (DEHP, ORadj = 3.893, 95% CI: 1.305-11.910, Padj = 0.015, Ptrend = 0.098) and dimethyl phthalate (DMP, ORadj = 1.722, 95% CI: 1.089-2.725, Padj = 0.020, Ptrend = 0.002) were significantly positively associated with the risk of FGR, while mono-butyl phthalate (MBP) showed a significant negative association with FGR (ORhigh = 0.192, 95% CI: 0.036-0.795, Padj = 0.033, Ptrend = 0.035) only among girls. The WQS model identified that BBP, di(2-ethyl)phthalate (DEP), DMP, DEHP, di-n-butyl phthalate (DBP), and MBP were highly weighted in the association with FGR. The BKMR model supported the positive association between joint exposure to phthalates and the risk of FGR and identified no significant interaction between the seven phthalates. Overall, maternal exposure to BBP, DEHP, and DMP may cause adverse effects on FGR, especially with combined effects.