Maternal pregnancy serum level of heptachlor epoxide, hexachlorobenzene, and β-hexachlorocyclohexane and risk of cryptorchidism in offspring
Prenatal exposure to environmental endocrine disrupters has been postulated to cause adverse effects on male reproductive health. Exposure to organochlorine pesticides with anti-androgenic and estrogenic potency has been shown to interfere with the sex-hormone-dependent process of testicular descent in animal models. We examined the relation between serum levels of the pesticides heptachlor epoxide (HCE), hexachlorobenzene (HCB), and β-hexachlorocyclohexane (β-HCCH) in pregnant women, and the occurrence of cryptorchidism in their sons. These three pesticides were previously suggested as risk factors for cryptorchidism. In a nested case-control design, we compared serum levels between mothers of cases (n=219) and controls (n=564), selected from the Collaborative Perinatal Project, a US birth cohort study of pregnancies in 1959-1966. The offspring of mothers with HCE levels above the 90th percentile compared to those below the 10th percentile had an adjusted odds ratio of cryptorchidism of 1.2 (95% confidence interval 0.6-2.6); for β-HCCH the odds ratio was 1.6 (0.7-3.6). For HCB the adjusted odds ratio was near one. These results provide little support for an association of cryptorchidism with exposure to low levels of HCE or HCB. For β-HCCH the findings were somewhat suggestive of an association but were inconclusive.