Phthalate exposure during preconception linked to higher risk of preterm birth

Maternal exposure to phthalates during the preconception period may be a potential risk factor for adverse pregnancy outcomes, including preterm birth, according to a new study published earlier this month in the journal Environmental Health.

In a preconception cohort study of 420 infants, researchers looked at both maternal and paternal urinary concentrations of biomarkers of phthalates and phthalate substitutes, including di-(2-ethylhexyl) phthalate and di(isononyl)cyclohexane-1,2-dicarboxylate.

Previous studies have linked phthalate exposure during pregnancy with preterm birth, so the current study aimed to examine the association of preconception exposure in either parent with preterm birth.

The study, conducted at an academic fertility center in Boston, Massachusetts, included a prospective preconception cohort of sub-fertile couples including 419 mothers and 229 fathers and their 420 live-born singleton offspring born between January 1, 2005 and December 31, 2018. Statistical analysis was performed from August 1 to October 31, 2019. Urinary concentrations of metabolites of phthalates and phthalate substitutes obtained before conception, the study said.

The researchers found that maternal preconception exposure to phthalate metabolites was associated with a 50 percent to 70 percent increased relative risk for preterm birth. The results suggest that female exposure to select phthalate plasticizers during the preconception period may be a potential risk factor for adverse pregnancy outcomes, which the researchers said may need to be considered in preconception care strategies.