Superfund Research Program
Biomarker Epidemiology of Exposure to Mixtures, Oxidative Stress, and Adverse Pregnancy Outcomes in Puerto Rico
Project Leader: John D. Meeker (University of Michigan)
Co-Investigators: Bhramar Mukherjee (University of Michigan), Deborah J. Watkins (University of Michigan)
Grant Number: P42ES017198
Funding Period: 2010-2025
Project-Specific Links
Final Progress Reports
Year: 2019 2013
Preterm birth is a major public health problem, especially in Puerto Rico. The Puerto Rico Test site for Exploring Contamination Threats (PROTECT) study is an ongoing investigation of environmental factors that contribute to preterm birth. In a preliminary analysis (n = 1090), John Meeker, Sc.D., and his team investigated the association between urinary phthalate metabolite concentrations measured at three study visits (approximately 20, 24, and 28 weeks gestation) with gestational age at delivery and preterm birth (Ferguson et al. 2019). The team additionally assessed differences in associations by study visit and among preterm births with a spontaneous delivery. Interquartile range (IQR) increases in pregnancy-averages of urinary metabolites of DBP and DiBP were associated with shorter duration of gestation and increased odds of preterm birth. An IQR increase in mono-n-butyl phthalate (MBP), a metabolite of DBP, was associated with 1.55 days shorter gestation (95 percent confidence interval [CI] = -2.68, -0.42) and an odds ratio (OR) of 1.42 (95 percent confidence interval [CI]: 1.07, 1.88) for preterm birth. An IQR increase in mono-isobutyl phthalate (MiBP), a metabolite of DiBP, was associated with 1.16 days shorter gestation (95 percent CI = -2.25, -0.08) and an OR of 1.32 (95 percent CI: 1.02, 1.71) for preterm birth. Associations were greatest in magnitude for urinary concentrations measured at the second study visit (median 23 weeks gestation). DiBP metabolite associations were greatest in magnitude in models of spontaneous preterm birth. In conclusion, among pregnant women in the PROTECT cohort, DBP and DiBP metabolites were associated with increased odds of preterm birth which may be contributing to elevated rates of preterm birth observed in Puerto Rico.