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 microg/m(3) [95% confidence interval [CI]: 0.18-0.21 microg/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.