Gender-specific relationship between prenatal exposure to phthalates and intrauterine growth restriction.

BACKGROUND

No study has examined the association between prenatal phthalate exposure and intrauterine growth retardation (IUGR). This study aimed to investigate whether prenatal exposure to phthalates was associated with increased risk of IUGR.

METHODS

A total of 126 mother-newborn pairs, including 42 IUGR cases and 84 control newborns and their mothers, were enrolled in this case-control study. Spot urine samples were collected during the third trimester of pregnancy, and 5 phthalate metabolites (mono-n-butyl phthalate (MBP), monomethyl phthalate (MMP), mono-2-ethylhexyl phthalate (MEHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP)) were measured.

RESULTS

Concentrations of MMP, MEHHP, MEOHP, and SumDEHP (MEHP, MEHHP, and MEOHP) were significantly higher in IUGR cases than in normal controls. In all subjects, urinary concentrations of MEHHP and MEOHP were significantly inversely associated with fetal growth indicators (birth weight and Quetelet's index). When mothers were stratified by infant sex, MEHHP and MEOHP concentrations were still negatively associated with fetal growth indicators, while no significant association was observed in females. In addition, exposure-response relationships were observed between MEHHP/SumDEHP concentrations in maternal urine and IUGR.

CONCLUSION

Prenatal exposure to phthalates was associated with increased risk of IUGR, and male newborns were more sensitive to phthalates than females.