Abstract

BackgroundIncreasing scientific evidence suggests that exposure to phthalates during pregnancy may be associated with an elevated risk of adverse reproductive outcomes such as preterm birth. Maternal endocrine disruption across pregnancy may be one pathway mediating some of these relationships. We investigated whether urinary phthalate metabolites were associated with maternal serum thyroid (free thyroxine [FT4], free triiodothyronine [FT3], and thyroid-stimulating hormone [TSH]), and sex (estradiol, progesterone, and sex hormone-binding globulin [SHBG]) hormone levels at multiple time points during pregnancy.MethodsPreliminary data (n = 106) were obtained from an ongoing prospective birth cohort in Northern Puerto Rico. We collected urine and serum sample at the first and third study visits that occurred at 18 +/- 2 and 26 +/- 2 weeks of gestation, respectively. To explore the longitudinal relationships between urinary phthalate metabolites and serum thyroid and sex hormone concentrations, we used linear mixed models (LMMs) adjusted for prepregnancy body mass index (BMI) and maternal age. An interaction term was added to each LMM to test whether the effect of urinary phthalate metabolites on serum thyroid and sex hormone levels varied by study visit. In cross-sectional analyses, we stratified BMI- and age-adjusted linear regression models by study visit.ResultsIn adjusted LMMs, we observed significant inverse associations between mono-3-carboxypropyl phthalate (MCPP) and FT3 and between mono-ethyl phthalate (MEP) and progesterone. In cross-sectional analyses by study visit, we detected stronger and statistically significant inverse associations at the third study visit between FT3 and MCPP as well as mono-carboxyisooctyl phthalate (MCOP); also at the third study visit, significant inverse associations were observed between FT4 and metabolites of di-(2-ethylhexyl) phthalate (DEHP). The inverse association between MEP and progesterone was consistent across study visits.ConclusionsIn this group of pregnant women, urinary phthalate metabolites may be associated with altered maternal serum thyroid and sex hormone levels, and the magnitude of these effects may depend on the timing of exposure during gestation.Electronic supplementary materialThe online version of this article (doi:10.1186/1477-7827-13-4) contains supplementary material, which is available to authorized users.

Highlights

  • Increasing scientific evidence suggests that exposure to phthalates during pregnancy may be associated with an elevated risk of adverse reproductive outcomes such as preterm birth

  • We investigated the relationship between urinary phthalate metabolites and maternal serum thyroid (FT3, FT4, and TSH) and sex hormone levels measured in samples collected at two time points in pregnancy from women participating in a prospective birth cohort in Puerto Rico

  • No statistically significant differences were observed between the demographic characteristics of study participants with measurable thyroid and sex hormone concentrations at visit 1 vs. those with measurable thyroid and sex hormone concentrations at visit 3

Read more

Summary

Introduction

Increasing scientific evidence suggests that exposure to phthalates during pregnancy may be associated with an elevated risk of adverse reproductive outcomes such as preterm birth. Many household and consumer products, including flooring and wall coverings, food packaging, and cosmetics such as lotions and fragrances, contain phthalates [2,3,4]. Due to their ubiquitous use, human exposure to phthalates is widespread [5]. Growing evidence suggests that urinary concentrations of phthalate metabolites during pregnancy are associated with adverse reproductive outcomes including preterm birth and pregnancy loss [8,9]. Hormonal production and regulation are critical for pregnancy maintenance and fetal growth and neurodevelopment; maternal endocrine disruption during pregnancy may be one pathway mediating some of these relationships [10,11,12,13]

Methods
Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call