A new study has purportedly found that “urinary phthalate metabolites were associated with increased oxidative stress biomarkers” in a population of 482 pregnant women. Kelly Ferguson, et al., “Urinary Phthalate Metabolites and Biomarkers of Oxidative Stress in Pregnant Women: A Repeated Measures Analysis,” Environmental Health Perspectives, November 2014. In addition to measuring nine phthalate metabolites at 10, 18, 26, and 35 weeks gestation as well as delivery, researchers with the University of Michigan and Harvard Medical School analyzed urinary levels of 8-hydroxydeoxyguanosine (8- OHdG) and 8-isoprostane as biomarkers of oxidative stress.

According to the results, “all phthalate metabolites were associated with higher concentrations of both biomarkers,” with mono-benzyl phthalate (MBzP), mono-n-butyl phthalate (MBP), and mono-isobutyl phthalate (MiBP) showing the strongest association with both outcome measures. “Increases in oxidative stress biomarkers in pregnant women have been associated with pregnancy loss, preeclampsia, preterm birth, and fetal growth restriction,” note the study’s authors. “These associations with phthalate exposure may be important for pregnancy outcomes that are mediated by oxidative stress mechanisms.”