Urinary Concentrations of Phthalate Metabolites and Pregnancy Loss Among Women Conceiving with Medically Assisted Reproduction

Abstract

Background: Animal studies demonstrate that several phthalates are embryofetotoxic and are associated with increased pregnancy loss and malformations. Results from human studies on phthalates and pregnancy loss are inconsistent. Methods: We examined pregnancy loss prospectively in relation to urinary phthalate metabolite concentrations among women undergoing medically assisted reproduction. We used data from 256 women conceiving 303 pregnancies recruited between 2004 and 2012 from the Massachusetts General Hospital Fertility Center. We quantified 11 phthalate metabolite concentrations and calculated the molar sum of four di(2-ethylhexyl) phthalate (DEHP) metabolites (ΣDEHP). We estimated risk ratios (RRs) and 95% confidence intervals for biochemical loss and total pregnancy loss (P trend = 0.04). RRs for total pregnancy loss were elevated in the highest quartiles of ΣDEHP and three DEHP metabolites. The remaining seven phthalate metabolite concentrations evaluated were not associated with either outcome. Conclusions: We found a suggestive pattern of association between conception cycle-specific urinary concentrations of DEHP metabolites and biochemical and total pregnancy loss among women undergoing medically assisted reproduction.