Objective To examine urinary phthalate metabolite concentrations in pregnant women with planned pregnancies in relation to history of infertility and use of assisted reproductive technology (ART). Design Phthalate metabolite concentrations were measured in first-trimester urine samples collected from women participating in a prospective pregnancy cohort study. Setting Prenatal clinics. Patient(s) A total of 750 women, of whom 86 had a history of infertility. Forty-one women used ART to conceive. Intervention(s) None. Main Outcome Measure(s) Primary outcomes were concentrations of four metabolites of diethylhexyl phthalate (DEHP) and their molar sum (∑DEHP). Multivariable analyses compared phthalate metabolite levels in  women reporting a history of infertility vs. those who did not (comparison group); and  those who used ART to conceive the index pregnancy vs. women with a history of infertility who did not use ART. Result(s) Among women with a history of infertility, ∑DEHP was significantly lower in women who conceived after ART compared with those who did not (geometric mean ratio: 0.83; 95% confidence interval 0.71-0.98). Similar significant associations were observed for all of the individual DEHP metabolites. There were no differences in DEHP metabolite concentrations between women with a history of infertility and the comparison group. Conclusion(s) Women who used ART to conceive had lower first-trimester phthalate metabolite concentrations than women with a history of infertility who did not use ART. Further research is needed to explore whether those pursuing fertility treatments take precautions to avoid exposure to environmental toxins, to improve treatment outcomes.
- endocrine-disrupting chemicals (EDCs)