Environmental anti-androgens and male reproductive health: focus on phthalates and testicular dysgenesis syndrome

The amount of research into endocrine disruption has exploded over the past decade and a re-evaluation of the state of research in this area is timely. There are debates about whether human male reproductive health is really declining and whether endocrine disrupting chemicals play any role in the perceived decline. Most data currently conclude that there are wide geographical variations in semen quality and in the incidence of testicular cancer, cryptorchidism and hypospadias. This review aims to give a brief overview of the issues surrounding the perceived decline in human male reproductive health and the importance of the hormonal environment for the development of the testis and reproductive tract. The consequences for the male reproductive tract of abnormal androgen levels or action are discussed with reference to environmental anti-androgenic compounds. The in vivo data on several anti-androgenic compounds that have been administered to pregnant rodents during the period of male reproductive tract development are assessed with attention to the effects on the male offspring. Finally, the data on in utero phthalate administration are discussed in detail to illustrate the similarities between the effects of some phthalate esters and the human male reproductive tract disorders which comprise testicular dysgenesis syndrome (TDS).