Gestational exposure to phthalates and gender-related play behaviors in 8-year-old children: an observational study.

Zana Percy,Bruce P Lanphear,Heidi Sucharew,Kimberly Yolton,Joseph M Braun,Jane C Khoury,Antonia M Calafat,Yingying Xu,Aimin Chen

doi:10.1186/s12940-016-0171-7

Abstract

BackgroundPhthalates, used in a variety of consumer products, are a group of chemicals that are ubiquitous in the environment, and their metabolites are detectable in most humans. Some phthalates have anti-androgenic properties; a prior study reported an association between gestational exposure to phthalates and reduced masculine behaviors in preschool boys.MethodsConcentrations of 9 phthalate metabolites were measured in urine collected at 16 and 26 weeks’ gestation from pregnant women enrolled in the HOME Study, a prospective pregnancy and birth cohort. Measures of gender-related play were collected at 8 years of age, including the Gender Identity Questionnaire (GIQ) completed by mothers, and the Playmate and Play Style Preferences Structured Interview (PPPSI) completed by children. We examined these measures as continuous variables using both bivariate and multivariable approaches with adjustment for covariates. Additional analyses included logistic regression of GIQ and PPPSI scores dichotomized by sex at the lower 25th percentile, indicating the least typical behavior.ResultsMothers’ phthalate metabolite concentrations during pregnancy were similar to the reported national average among US women. All children scored within a typical range on both measures of gender-related play behavior. No statistically significant associations were found between averaged maternal phthalate metabolite concentrations and continuous PPPSI scores or any GIQ scores. For the dichotomized PPPSI; higher maternal monoethyl phthalate (MEP) concentrations were associated with more typical play behaviors for females (OR = 0.70, CI = 0.51–0.97). In contrast, higher maternal mono-isobutyl phthalate (MiBP) concentrations were associated with higher odds of membership in the least typical play behaviors group for males (OR = 1.69, CI = 1.00–2.86).ConclusionsIn this sample of typically developing children, higher maternal urinary MEP concentrations during pregnancy were associated with more typical gender-related play behaviors in both males and females, and increased urinary MiBP concentrations were associated with less masculine gender-related play behaviors in males.

Highlights

Phthalates, used in a variety of consumer products, are a group of chemicals that are ubiquitous in the environment, and their metabolites are detectable in most humans
In bivariate analyses stratified by sex, we found no significant associations between phthalate metabolite concentrations and the Gender Identity Questionnaire (GIQ) or Playmate and Play Style Preferences Structured Interview (PPPSI) scales examined as continuous variables
In this study of typically developing children from a cohort that has been followed since the second trimester of gestation, we found no significant associations between maternal phthalate concentrations during pregnancy and gender-related play behaviors in children at age 8 years when the play measures were examined as continuous variables

Summary

Introduction

Phthalates, used in a variety of consumer products, are a group of chemicals that are ubiquitous in the environment, and their metabolites are detectable in most humans. Phthalates, are a multifunctional group of chemicals found in a variety of consumer products including vinyl flooring, shower curtains, raincoats, bath products, nail polish, perfumes, cosmetics, medications, and food storage containers. Phthalates are ubiquitous in the modern environment and enter our bodies through food consumption, inhalation, or dermal contact [1,2,3]. After phthalates enter the body, they are quickly metabolized into their respective hydrolytic and oxidative monoester metabolites, conjugated, and excreted into the urine by the kidneys [4]. The long-term consequences of human exposure to phthalates are poorly understood. Rapid brain development and immature detoxification pathways make fetuses vulnerable to neurotoxicants

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