James-Todd, TamarraMeeker, John DHuang, TianyiHauser, RussSeely, EllenFerguson, Kelly KRich-Edwards, JanetMcElrath, Thomas2016-11-182016James-Todd, Tamarra M, John D Meeker, Tianyi Huang, Russ Hauser, Ellen W Seely, Kelly K Ferguson, Janet W Rich-Edwards, and Thomas F McElrath. 2016. Racial and Ethnic Variations in Phthalate Metabolite Concentration Changes Across Full-Term Pregnancies. Journal of Exposure Science and Environmental Epidemiology (February 10). doi:10.1038/jes.2016.2. http://dx.doi.org/10.1038/jes.2016.2.1559-0631http://nrs.harvard.edu/urn-3:HUL.InstRepos:29412073Higher concentrations of certain phthalate metabolites are associated with adverse reproductive and pregnancy outcomes, as well as poor infant/child health outcomes. In non-pregnant populations, phthalate metabolite concentrations vary by race/ethnicity. Few studies have documented racial/ethnic differences between phthalate metabolite concentrations at multiple time points across the full-course of pregnancy. The objective of the study was to characterize the change in phthalate metabolite concentrations by race/ethnicity across multiple pregnancy time points. Women were participants in a prospectively collected pregnancy cohort who delivered at term (≥37 weeks) and had available urinary phthalate metabolite concentrations for ≥ 3 time points across full-term pregnancies (n = 350 women). We assessed urinary concentrations of eight phthalate metabolites that were log-transformed and specific gravity-adjusted. We evaluated the potential racial/ethnic differences in phthalate metabolite concentrations at baseline (median 10 weeks gestation) using ANOVA and across pregnancy using linear mixed models to calculate the percent change and 95% confidence intervals adjusted for sociodemographic and lifestyle factors. Almost 30% of the population were non-Hispanic black or Hispanic. With the exception of mono-(3 carboxypropyl) (MCPP) and di-ethylhexyl phthalate (DEHP) metabolites, baseline levels of phthalate metabolites were significantly higher in non-whites (Po0.05). When evaluating patterns by race/ethnicity, mono-ethyl phthalate (MEP) and MCPP had significant percent changes across pregnancy. MEP was higher in Hispanics at baseline and decreased in mid-pregnancy but increased in late pregnancy for non-Hispanic blacks. MCPP was substantially higher in non-Hispanic blacks at baseline but decreased later in pregnancy. Across pregnancy, non-Hispanic black and Hispanic women had higher concentrations of certain phthalate metabolites. These differences may have implications for racial/ethnic differences in adverse pregnancy and child health outcomes.en-USblacksethnicityHispanicsphthalatespregnancyraceJournal Article10.1038/jes.2016.2