Prenatal Di(2-ethylhexyl)Phthalate Exposure and Length of Gestation Among an Inner-City Cohort

OBJECTIVE: Our objective was to assess the relationship between di(2-ethylhexyl)phthalate (DEHP) exposure during pregnancy and gestational age at delivery among 311 African American or Dominican women from New York City. METHODS: Forty-eight-hour personal air and/or spot urine samples were collected during the third trimester. DEHP levels were measured in air samples and 4 DEHP metabolite levels were measured in urine. Specific gravity was used to adjust for urinary dilution. Gestational age was abstracted from newborn medical records (n = 289) or calculated from the expected date of delivery (n = 42). Multivariate linear regression models controlled for potential confounders. RESULTS: DEHP was detected in 100% of personal air samples (geometric mean: 0.20 mu g/m(3) [95% confidence interval [CI]: 0.18-0.21 mu g/m(3)]); natural logarithms of air concentrations were inversely but not significantly associated with gestational age. Two or more of the DEHP metabolites were detected in 100% of urine samples (geometric mean: 4.8-38.9 ng/mL [95% CI: 4.1-44.3 ng/mL]). Controlling for potential confounders, gestational age was shorter by 1.1 days (95% CI: 0.2-1.8 days) for each 1-logarithmic unit increase in specific gravity-adjusted mono(2-ethylhexyl) phthalate concentrations (P = .01) and averaged 5.0 days (95% CI: 2.1-8.0 days) less among subjects with the highest versus lowest quartile concentrations (P =. 001). Results were similar and statistically significant for the other DEHP metabolites. CONCLUSIONS: Prenatal DEHP exposure was associated with shorter gestation but, given inconsistencies with previous findings for other study populations, results should be interpreted with caution, and additional research is warranted. Pediatrics 2009; 124: e1213-e1220