The Role of the Environment in Testicular Dysgenesis Syndrome

Abstract

In the last 50 years a significant progressive decline of male reproductive health has been documented, with increasing occurrence of semen quality impairment and of some interlinked male genital abnormalities, such as hypospadias, cryptorchidism, and testicular germ-cell cancer, which probably share a common origin during prenatal life and are therefore grouped in a unique pathological condition named testicular dysgenesis syndrome. Since in animal studies endocrine disrupting compounds exerting estrogenic and/or anti-androgenic effects have been demonstrated to significantly impair male reproductive function, a potential etiological role in the occurrence of testicular dysgenesis syndrome has also been postulated. Human studies focusing on the potential role of endocrine disrupting compounds in the development of testicular dysgenesis syndrome are clearly based on prenatal exposure, mainly and heterogeneously assessed by quantification of these compounds in maternal samples at various pregnancy stages; nevertheless, studies are fragmented and very often do not account for multiple exposures, therefore commonly resulting in controversial results. This chapter aimed at providing a summary of available animal and human evidence concerning the association between prenatal exposure to endocrine disrupting compounds, including compounds with estrogenic (diethylstilbestrol, bisphenol A), anti-androgenic (phthalates, pesticides, heavy metals), and mixed estrogenic and anti-androgenic (pesticides dichlorodiphenyltrichloroethane and dichlorodiphenyldichloroethylene, flame retardants, polychlorinated biphenyls, dioxins) properties, and the development of specific components of testicular dysgenesis syndrome, particularly, hypospadias, cryptorchidism, and testicular germ-cell cancer, by outlining their effect per se, independently on genetic and lifestyle factors.