Environ Int

BackgroundOrtho-phthalates are known endocrine disruptors. Prenatal phthalate exposure has been inconsistently associated with fetal growth and infant birth weight; however, the effect of paternal and maternal preconception exposure remains understudied.ObjectivesTo investigate associations of paternal and maternal preconception and maternal prenatal urinary phthalate metabolite concentrations with birth weight.MethodsThe study comprised 364 singletons born to 364 mothers and 195 fathers (195 couples) from the EARTH Study, a prospective cohort of couples from Boston, MA. Births were categorized by mode of conception: in-vitro fertilization based (IVF) (n=208) or non-IVF based (n=156, intrauterine insemination or non-medically assisted/natural conception). We measured urinary concentrations of eleven phthalate metabolites in maternal (n=1,425) and paternal (n=489) preconception and maternal prenatal (n=781) samples. Birth weight was abstracted from delivery records. Covariate-adjusted associations between loge-phthalate metabolite concentrations and birth weight were evaluated separately by mode of conception using multivariable linear regression.ResultsEach loge-unit increase in paternal urinary concentration of the sum of di(2-ethylhexyl) phthalate (\u3a3DEHP) metabolites was associated with a 90 gram (95% CI: 12165, 1215) decrease in birth weight among IVF singletons, but not among non-IVF singletons (18 grams; 95% CI: 1276, 113). Additional adjustment for maternal prenatal \u3a3DEHP concentrations modestly strengthened findings among IVF singletons. While few associations were found with maternal preconception phthalate metabolites, we observed an inverse relationship between several maternal prenatal urinary phthalate metabolite concentrations and birth weight among IVF singletons in covariate-adjusted models. However, with further adjustment for specific paternal phthalate metabolite concentrations, these associations were attenuated and no longer significant.ConclusionsPaternal preconception urinary concentration of \u3a3DEHP metabolites was associated with a decrease in birth weight among IVF-conceived singletons. These results, if replicated, highlight the importance of preconception health, especially among subfertile couples.CC999999/Intramural CDC HHSUnited States/R01 ES009718/ES/NIEHS NIH HHSUnited States/R01 ES024381/ES/NIEHS NIH HHSUnited States/CIHRCanada