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BACKGROUND: Phthalate exposures are ubiquitous during pregnancy and may contribute to racial and ethnic disparities in preterm birth. OBJECTIVES: We investigated race and ethnicity in the relationship between biomarkers of phthalate exposure and preterm birth by examining: a) how hypothetical reductions in racial and ethnic disparities in phthalate metabolites might reduce the probability of preterm birth; and b) exposure–response models stratified by race and ethnicity. METHODS: We pooled individual-level data on 6,045 pregnancies from 16 U.S. cohorts. We investigated covariate-adjusted differences in nine urinary phthalate metabolite concentrations by race and ethnicity [non-Hispanic White (White, 43%), non-Hispanic Black (Black, 13%), Hispanic/Latina (38%), and Asian/Pacific Islander (3%)]. Using g-computation, we estimated changes in the probability of preterm birth under hypothetical interventions to eliminate disparities in levels of urinary phthalate metabolites by proportionally lowering average concentrations in Black and Hispanic/ Latina participants to be approximately equal to the averages in White participants. We also used race and ethnicity-stratified logistic regression to characterize associations between phthalate metabolites and preterm birth. RESULTS: In comparison with concentrations among White participants, adjusted mean phthalate metabolite concentrations were consistently higher among Black and Hispanic/Latina participants by 23%–148% and 4%–94%, respectively. Asian/Pacific Islander participants had metabolite levels that were similar to those of White participants. Hypothetical interventions to reduce disparities in metabolite mixtures were associated with lower probabilities of preterm birth for Black [13% relative reduction; 95% confidence interval (CI): -34%, 8.6%] and Hispanic/Latina (9% relative reduction; 95% CI: -19%, 0.8%) participants. Odds ratios for preterm birth in association with phthalate metabolites demonstrated heterogeneity by race and ethnicity for two individual metabolites (mono-n-butyl and monoisobutyl phthalate), with positive associations that were larger in magnitude observed among Black or Hispanic/Latina participants. CONCLUSIONS: Phthalate metabolite concentrations differed substantially by race and ethnicity. Our results show hypothetical interventions to reduce population-level racial and ethnic disparities in biomarkers of phthalate exposure could potentially reduce the probability of preterm birth. [ABSTRACT FROM AUTHOR]

Context: Steroids play an important role in fetal development and parturition. Gestational exposures to endocrine-disrupting chemicals (EDCs) affect steroidal milieu and pregnancy outcomes, raising the possibility of steroids serving as biomarkers. Most studies have not addressed the impact of EDC mixtures, which are reflective of real life scenarios.Objective: Assess the association of maternal and neonatal steroids with pregnancy outcomes and early pregnancy EDC levels.Design: Prospective analysis of mother-infant dyads.Setting: University hospital.Participants: 121 mother-infant dyads.Main Outcome Measures: The associations of maternal and neonatal steroidal hormones from 121 dyads with pregnancy outcomes, the associations of first trimester EDCs individually and as mixtures with maternal and neonatal steroids in a subset of 56 dyads and the influence of body mass index (BMI), age, and offspring sex in modulating the EDC associations with steroids were determined.Results: Steroid-specific positive or negative associations with pregnancy measures were evident; many maternal first trimester EDCs were negatively associated with estrogens and positively with androgen/estrogen ratios; EDC-steroid associations were influenced by maternal age, pre-pregnancy BMI, and fetal sex; and EDCs individually and as mixtures showed direct and inverse fetal sex-dependent associations with maternal and neonatal steroids.Conclusions: This proof-of-concept study indicates association of steroids with pregnancy outcomes depending on maternal age, prepregnancy BMI, and fetal sex, with the effects of EDCs differing when considered individually or as mixtures. These findings suggest that steroidal hormonal measures have potential to serve as biomarkers of impact of EDC exposures and pregnancy outcome. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the relationship between urinary bisphenol A (BPA) levels and measures of adiposity and chronic disease risk factors for a nationally representative US pediatric sample., Methods: We used the NHANES 2003-2010 to evaluate cross-sectional associations between urinary BPA and multiple measures of adiposity, cholesterol, insulin, and glucose for children aged 6 to 18 years, adjusting for relevant covariates (eg, demographics, urine creatinine, tobacco exposure, and soda consumption)., Results: We found a higher odds of obesity (BMI ≥95th percentile) with increasing quartiles of BPA for quartiles 2 vs 1 (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.17-2.60, P = .008), 3 vs 1 (OR 1.64, 95% CI 1.09-2.47, P = .02), and 4 vs 1 (OR 2.01, 95% CI 1.36-2.98, P = .001). We also found a higher odds of having an abnormal waist circumference-to-height ratio (quartiles 2 vs 1 [OR 1.37, 95% CI 0.98-1.93, P = .07], 3 vs 1 [OR 1.41, 95% CI 1.07-1.87, P = .02], and 4 vs 1 [OR 1.55, 95% CI 1.12-2.15, P = .01]). We did not find significant associations of BPA with any other chronic disease risk factors., Conclusions: Higher levels of urinary BPA were associated with a higher odds of obesity (BMI >95%) and abnormal waist circumference-to-height ratio. Longitudinal analyses are needed to elucidate temporal relationships between BPA exposure and the development of obesity and chronic disease risk factors in children.