Prenatal phthalate exposure and reproductive function in young men

Abstract

Background: Prenatal exposure to phthalates is suggested to negatively impact male reproductive function, but human data are lacking.

Objectives: To study associations between prenatal exposure to diethylhexyl phthalate (DEHP) and diisononyl phthalate (DiNP), and reproductive parameters of adolescent men.

Methods: Using linear regression models adjusted for potential confounders, we studied associations between levels of DEHP- and DiNP metabolites in maternal sera from mean 12 weeks of pregnancy, and testicular size, semen quality and reproductive hormones in 112 adolescent sons, recruited from the general population.

Results: Men in the highest exposure tertile of one DiNP metabolite [mono-(carboxy-iso-octyl) phthalate], compared with men in the lowest tertile had: 4.3mL (95% CI: 0.89, 7.6mL; p<0.001) lower total testicular volume; 30% (95% CI: 3.6, 63%; p=0.02) higher levels of follicle-stimulating hormone; and 0.87mL (95% CI: 0.28, 1.5mL; p=0.004) lower semen volume. Men in the highest exposure tertile of one DEHP metabolite [mono-(2-ethyl-5-hydroxylhexyl) phthalate] had 0.70mL (95% CI: 0.090, 1.3mL; p=0.03) lower semen volume than men in the lowest exposure tertile. The levels of two DiNP metabolites [mono-(hydroxy-iso-nonyl) phthalate and mono-(oxo-iso-nonyl) phthalate] were linearly associated with luteinizing hormone (p<0.01).

Conclusion: Prenatal levels of some metabolites of DEHP and DiNP seemed negatively associated with reproductive function of adolescent men.

Keywords: Diethylhexyl phthalate; Diisononyl phthalate; Late effects; Prenatal exposure; Semen quality; hormones.