Flame retardants in placenta and breast milk and cryptorchildism in newborn boys

Abstract

Background: Polybrominated diphenyl ethers (PBDEs) are widely used in Western countries Objectives: Because the prevalence of cryptotchidism appears to be increasing, we investigated whether exposure to PBDEs was associated with testicular maldescent. Methods: In a prospective Danish-Finnish study, 1997-2001, all boys were examined for cryptorchidism. We analyzed whole placements (for 95 cryptorchild/185 healthy boys) and individual breat milk samples (62/68) for 14 PBDEs and infant serum samples for gonadotropins, sex-hormone binding globulin, testosterone and inhibin B. Results: In 86 placenta-milk pairs, placenta PBDE concentrations in fat were lower than in breats milk, and a larger number of congeners were nondectable. There was no significant difference between boys with and without crytorchidism for individual congeners, the sum of 5 most prevalent or all 14 congeners. The concentration of PBDEs in breast milk was significantly higher in boys with cryptorchidism than in controls (sum of BDEs 47, 153, 99, 100, 28, 66 and 154: median, 4.16 vs. 3.16 ng/ g fat; p <0.033). The sum of PBDEs in breast milk did not differ between Denmark and Finland (median, 3.52 vs. 3.44 ng/g fat), but significant difference in some individual congeners were found. Conclusions: Two different proxies were used for prenatal PBDE exposure, and levels in breast milk, but not in placenta, showed an association with congenital cryptorchidism. Other environmental factors may contribute to cryptorchidism. Our observation are of concern because human exposure to PBDEs is high in some geographic areas.