Maternal Food and Beverage Consumption Behaviors and Discrepant Phthalate Exposure by Race.

Background: Differential exposure to endocrine-disrupting chemicals, including phthalate diesters, may contribute to persistent racial/ethnic disparities in women's reproductive health outcomes. We sought to characterize sources of gestational exposure to these agents that may differ according to maternal race. Methods: We enrolled pregnant Black (n = 198), including African American, and White (n = 197) women during the second trimester, and measured eight phthalate monoester metabolites in urine. We assessed confounder-adjusted associations between multiple food and beverage consumption habits, summarized using a principal component analysis, as predictors of maternal urinary phthalate metabolite levels, stratified by race. Results: Whites reported significantly greater unprocessed food consumption (42.5% vs. 32.0%; p < 0.001) and storage of food in clear unbreakable plastic containers (66.5% vs. 49.3%; p < 0.001) than Blacks, while Blacks consumed more canned fruits and vegetables (23.5% vs. 12.2%; p < 0.001) than Whites. Using plastics for food storage, microwaving in plastic containers, and using hard plastic water bottles was associated with urinary phthalate concentrations, especially DEHP metabolites (e.g., mean difference = 5.13%; 95% CI: 3.05, 7.25). These associations were driven primarily by Black pregnant women. Conclusions: Targeted interventions to reduce maternal exposure to phthalates need to be designed with specific attention to differences in food and beverage consumption behaviors among Black and White women.

Association between gestational phthalate exposure and newborn head circumference; impacts by race and sex.

Observational and experimental studies report associations between gestational phthalate exposure and fetal development, yet few data exist to characterize phthalate effects on head circumference (HC) or to estimate the impact of race or sex. To address this data gap, we enrolled 152 African American and 158 white mothers with uncomplicated singleton pregnancies from the Charleston, South Carolina (USA) metropolitan area in a prospective birth cohort. Study participants provided up to two urine specimens during mid and late gestation, completed a study questionnaire, and allowed access to hospital birth records. We measured eight phthalate monoester metabolites using liquid chromatography with tandem mass spectrometry, and calculated molar sums of phthalate parent diesters. After specific gravity correction, we tested for associations between phthalates and neonatal HC (cm) and cephalization index (cm/g) using multiple informant linear regression with inverse probability weighting to account for selection bias between repeated urine sampling, adjusted for maternal race, age, body mass index, education, and smoking. We explored interactions by maternal race and infant sex. A doubling of urinary monoethyl phthalate (MEP) concentration was associated with a -0.49% (95%CI: -0.95%, -0.02%) smaller head circumference, although seven other phthalate metabolites were null. There were no statistically significant associations with cephalization index. HC was larger for whites than African American newborns (p < 0.0001) but similar for males and females (p = 0.16). We detected interactions for maternal race with urinary monobutyl phthalate (MBP; p = 0.03), monobenzyl phthalate (MBzP; p = 0.01), monoethylhexyl phthalate (MEHP; p = 0.05), monomethyl phthalate (MMP; p = 0.02), and the sum of dibutyl phthalate metabolites (∑DBP; p = 0.05), in which reduced HC circumference associations were stronger among whites than African Americans, and interactions for sex with MBP (p = 0.08) and MiBP (p = 0.03), in which associations were stronger for females than males. Our results suggest that gestational phthalate exposure is associated with smaller neonatal HC and that white mothers and female newborns have greater susceptibility.

Racial disparity in maternal phthalates exposure; Association with racial disparity in fetal growth and birth outcomes.

Experimental and observational data implicate phthalates as developmental toxicants. However, few data are available to assess the maternal risks of gestational exposure by race and infant sex. To begin to address this data gap, we characterized associations between maternal urinary phthalate metabolites and birth outcomes among African American and white mothers from a southeastern U.S. population. We enrolled pregnant African American (n = 152) and white (n = 158) women with singleton live births between 18 and 22 weeks gestation. We measured phthalate metabolites (mono-n-butyl phthalate (MBP), monoisobutyl phthalate (MiBP), monobenzyl phthalate (MBzP), mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), monoethyl phthalate (MEP), monomethyl phthalate (MMP), and the sums of DEHP (ΣDEHP) and DBP (ΣDBP) metabolites) in up to two gestational urine specimens from mothers, and evaluated confounder-adjusted associations per natural log unit greater concentration with birth weight for gestational age z-score, small for gestational age (SGA; <10th %tile), preterm birth (PTB; <37 weeks gestation), and low birth weight (LBW; <2500 g). We also tested for interactions by maternal race and infant sex. We found that lower z-scores were associated with greater MiBP (ß = -0.28; 95% CI: -0.54, -0.02) and MMP (ß = -0.30; 95% CI: -0.52, -0.09) concentrations, while MEP interacted with race (p = 0.04), indicating an association among whites (ß = -0.14; 95% CI: -0.28, 0.001) but not among African Americans (ß = 0.05; 95% CI = -0.09, 0.19). Greater MiBP (OR = 2.82; 95% CI: 1.21, 6.56) and MEOHP (OR = 2.80; 95% CI: 1.05, 7.42) were associated with an overall higher SGA risk, greater MEHP was associated with higher SGA risk (p = 0.10) in whites (OR = 3.26 95% CI: 0.64, 16.56) but not in African Americans (OR = 0.71 95% CI: 0.07, 7.17), and the associations for MiBP (p = 0.02) and ΣDBP (p = 0.02) varied by infant sex. We detected interactions for PTB in which African Americans were at higher risk than whites for greater MiBP (p = 0.08) and MEP (p = 0.02) although lower risk for greater MEHP (p = 0.09). Greater MEP was associated with an overall higher LBW risk (OR = 1.33; 95% CI: 0.95, 1.86), and males were at higher risk than females with greater MBP (p = 0.002), MiBP (p = 0.02), MBzP (p = 0.01), MEP (p = 0.002), MMP (p = 0.09), and ΣDBP (p = 0.01) concentrations. Overall, our results suggest that gestational phthalate exposure is associated with adverse maternal birth outcomes, and that the effects vary by maternal race and infant sex.

Influence of race on prenatal phthalate exposure and anogenital measurements among boys and girls.

BACKGROUND: Select phthalates have antiandrogenic activity, which raises concern for adverse developmental outcomes given widespread exposure of pregnant women. Investigators have reported associations between maternal urinary phthalates and altered anogenital distance (AGD), a marker of in utero androgen activity, among offspring. However, data assessing the impact of race on these associations is sparse. OBJECTIVES: To evaluate associations between prenatal phthalate exposure and AGD in a racially diverse newborn population. METHODS: We prospectively collected second trimester urine from 187 African American and 193 white mothers, and used liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) to measure eight phthalate metabolites and calculate molar sums. We measured anopenile (APD) and anoscrotal (ASD) distances of 171 boys and anoclitoral (ACD) and anofourchette (AFD) distances of 128 girls at delivery. We collected sociodemographic and clinical data from questionnaires and delivery records. RESULTS: We identified a statistically significant inverse association for mono-2-ethylhexyl phthalate (MEHP) and APD in boys (B=-1.57mm, p=0.02), which was stronger for African Americans (B=-2.07mm, p=0.04) than for whites (B=-1.23mm, p=0.22), although the racial interaction was not statistically significant (p=0.56). We found a longer ASD for higher molar sums of dibutyl phthalate (∑DBP; B=0.99mm, p=0.04), with stronger associations for whites (B=1.30mm, p=0.04) than for African Americans (B=0.39mm, p=0.59), again without a statistically significant racial interaction (p=0.34). Among girls, we found inverse associations for tertiles of MEHP with AFD and ACD, and statistically significant race-based interactions, in which ACD was longer for whites and shorter for African Americans, following exposure to monoethyl phthalate (MEP; p=0.01) and ∑DBP (p=0.08). CONCLUSIONS: Our findings suggest race and sex play important roles in phthalate-associated reproductive developmental toxicity, with important implications for designing future investigations and health interventions.

Prevalence and predictors of phthalate exposure in pregnant women in Charleston, SC.

Phthalates are plasticizers commonly detected in human urine due to widespread exposure from PVC plastics, food packaging, and personal care products. Several phthalates are known antiandrogenic endocrine disruptors, which raises concern for prenatal exposure during critical windows of fetal development. While phthalate exposure is ubiquitous, certain demographics are subject to greater or lesser exposure. We sampled urine from 378 pregnant women during the second trimester of gestation living in Charleston, SC, and measured eight urinary phthalate metabolites as biomarkers of phthalate exposure: monobutyl phthalate (MBP), monobenzyl phthalate (MBzP), mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), monoethyl phthalate (MEP), monoisobutyl phthalate (MiBP), and monomethyl phthalate (MMP). Demographic data was collected from questionnaires administered at the time of specimen collection. All phthalate metabolites were detected in over 93% of urine samples. On average, concentrations were highest for MEP (median = 47.0 ng/mL) and lowest for MMP (median = 1.92 ng/mL). Sociodemographic characteristics associated with elevated phthalate concentrations included being unmarried, less educated, having a low income, high body mass index (BMI), and/or being African American. After racial stratification, age, BMI, education, and income were significantly associated with phthalate concentrations in African American women. Marital status was associated with phthalate concentrations in Caucasian women only, with greater concentrations of MBP, MEHHP, MiBP, and MMP in unmarried versus married women. Results of this cross-sectional study provide evidence for significant racial and demographic variations in phthalate exposure.

Fetal Surveillance and Timing of Delivery for Multiples.

This chapter describes the current evidence and recommendations for surveillance and delivery timing for multifetal gestations. Ultrasound surveillance should include early determination of chorionicity, anatomic survey for all twins with fetal echocardiography for monochorionic twins, and growth assessment every 4 weeks. Monochorionic twins should also undergo ultrasound surveillance for twin-twin transfusion syndrome every 2 weeks starting at 16 weeks. Weekly testing with nonstress tests or biophysical profiles is recommended at 32 weeks for monochorionic, diamniotic twins, and 34 weeks for dichorionic twins. If this surveillance is reassuring, optimal delivery timing is 36 weeks 0 days to 37 weeks 0 days for monochorionic, diamniotic twins, and 37 week 0 days to 38 weeks 0 days for dichorionic twins.

Risk of late-preterm stillbirth and neonatal morbidity for monochorionic and dichorionic twins.

OBJECTIVE: The purpose of this study was to determine the prospective risk of intrauterine fetal death (IUFD) at ≥34 weeks' gestation for monochorionic and dichorionic twins receiving intensive antenatal fetal surveillance. The secondary objective was to calculate the incidence of prematurity-related neonatal morbidity/mortality rates that have been stratified by gestational week and chorionicity. STUDY DESIGN: A retrospective cohort study of all twins at ≥34 weeks' gestation who were delivered at the Medical University of South Carolina (1987-2010) was performed. Twins were cared for in a longstanding Twin Clinic with standardized treatment and surveillance protocols and supervised by a consistent Maternal-Fetal Medicine specialist. Gestational age-specific fetal/neonatal mortality rates and composite neonatal morbidity rates were compared by chorionicity. A generalized linear mixed model was used to identify variables that were associated with increased composite neonatal morbidity. RESULTS: Among 768 twin gestations (601 dichorionic and 167 monochorionic), only 1 dichorionic IUFD occurred. The prospective risk of IUFD at ≥34 weeks' gestation was 0.17% for dichorionic twins and 0% for monochorionic twins. Composite neonatal morbidity decreased with each gestational week (P < .0001). Morbidity was increased by white race, gestational diabetes mellitus, and elective indication for delivery. The nadir of composite neonatal morbidity occurred at 36/0-36/6 weeks' gestation for monochorionic twins and 37/0-37/6 weeks' gestation for dichorionic twins. CONCLUSION: Our data do not support concern for an increased risk of stillbirth in uncomplicated intensively monitored monochorionic twins at ≥34 weeks' gestation. However, our data do show significantly increased rates of neonatal morbidity in late preterm monochorionic twins that cannot be justified by a corresponding reduction in the risk of stillbirth. We believe that our data support delivery of uncomplicated monochorionic twins at 37 weeks' gestation.