First trimester phthalate exposure and male newborn genital anomalies

Anti-androgenic phthalates are environmental chemicals that affect male genital development in rodents leading to genitourinary birth defects. The authors examined whether first trimester phthalate exposure may exert similar effects in humans leading to an increased incidence of newborn male genital anomalies in a multi-centre cohort study. First trimester pregnant women within The Infant Development and the Environment Study (TIDES) from 2010 to 2012 from four study centres and limited analyses to all mother/male infant dyads who had complete urinary phthalate and birth exam data (N=371) were recruited for the study. Multivariate logistic regression was used to determine the odds of having a genital anomaly in relation to phthalate exposure. Hydrocele was the primary abnormality observed in the cohort (N=30) followed by undescended testes (N=5) and hypospadias (N=3). A statistically significant 2.5-fold increased risk (95% CI 1.1, 5.9) of having any anomaly and 3.0-fold increased risk (95% CI 1.2, 7.6) of isolated hydrocele in relation to a one log unit increase in the sum of di-ethylhexyl phthalate (DEHP) metabolites was observed. The authors concluded that first trimester urinary DEHP metabolite concentrations were associated with increased odds of any newborn genital anomaly, and this association was primarily driven by isolated hydrocele which made up the majority of anomalies in newborn males. The association with hydrocele has not been previously reported and suggests that it may be an endpoint affected by prenatal phthalate exposures in the first trimester of development. Future human studies should include hydrocele assessment in order to confirm findings.

Authors: Sathyanarayana S, Grady R, Barrett ES, Redmon B, Nguyen RH, Barthold JS, Bush NR, Swan SH. ;Full Source: Environmental Research. 2016 Nov; 151:777-782. doi: 10.1016/j.envres.2016.07.043. Epub 2016 Aug 23. ;