First Trimester Phthalate Exposure and Infant Birth Weight in the Infant Development and Environment Study.

Sheela Sathyanarayana,Bruce Redmon,Wren Haaland,Ruby Nguyen,Emily Barrett,Shanna Swan

doi:10.3390/ijerph13100945

Abstract

Phthalate exposure is widespread among pregnant women but whether it is related to fetal growth and birth weight remains to be determined. We examined whether first trimester prenatal phthalate exposure was associated with birth weight in a pregnancy cohort study. We recruited first trimester pregnant women from 2010–2012 from four centers and analyzed mother/infant dyads who had complete urinary phthalate and birth record data (N = 753). We conducted multiple linear regression to examine if prenatal log specific gravity adjusted urinary phthalate exposure was related to birthweight in term and preterm (≤37 weeks) infants, stratified by sex. We observed a significant association between mono carboxy-isononyl phthalate (MCOP) exposure and increased birthweight in term males, 0.13 kg (95% CI 0.03, 0.23). In preterm infants, we observed a 0.49 kg (95% CI 0.09, 0.89) increase in birthweight in relation to a one log unit change in the sum of di-ethylhexyl phthalate (DEHP) metabolite concentrations in females (N = 33). In summary, we observed few associations between prenatal phthalate exposure and birthweight. Positive associations may be attributable to unresolved confounding in term infants and limited sample size in preterm infants.

Highlights

Low birth weight and intrauterine growth retardation are significant risk factors for future morbidity including obesity and poor cognitive function [1], yet identification of modifiable environmental exposures that influence fetal growth remains to be determined
The percentage of samples above the limit of detection ranged from 66%–99%, and the distribution of phthalate concentrations is shown in Table 2 and reported in previous publications in further detail [19]
Our analysis found little evidence to support a relationship between first trimester prenatal phthalate exposure and birth weight; and while there is a suggestion of an effect in preterm infants in a sex-specific manner, the sample size is too small to draw conclusions

Summary

Introduction

Low birth weight and intrauterine growth retardation are significant risk factors for future morbidity including obesity and poor cognitive function [1], yet identification of modifiable environmental exposures that influence fetal growth remains to be determined. Phthalates are a class of man-made chemicals that are ubiquitous in the general population [2]. Pregnant women have widespread exposure from contact with plastic products, personal care products, contaminated foods, and dust [3]. Phthalates cross the placenta and can impact fetal development leading to adverse reproductive outcomes [3] via hormone mediation, oxidative stress, and peroxisome proliferator. Res. Public Health 2016, 13, 945; doi:10.3390/ijerph13100945 www.mdpi.com/journal/ijerph

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