Trends in male reproductive health. Environmental aspects.

Abstract

During the past five years, several researchers have focused on recent trends of declining male reproductive health. Almost all cancer registries in the Western World have noted a remarkable increase in testicular cancer. Thus, in Scandinavia, where the incidence of testicular cancer is particularly high, there has been a three to four-fold increase during the past 50 years. The same trend has been found among U.S. whites, although no increase has been demonstrated among Afro-Americans who generally have a very low risk of testicular cancer. During the same period, we have several indications of decrease in semen quality - again the bulk of the data come from the Western World. There are also data to suggest that the incidence of other genital abnormalities, including hypospadias and undescended testis are weaker. The fact that the reported changes the reported changes in male reproductive health have occurred simultaneously within a short period of time suggests that common environmental factors are of importance. As normal sexual differentiation, development of the gonads and normal postnatal development are essential for normal reproductive function in adulthood, it was suggested that a common foetal factor could play a part for the observed trends. Based on epidemiological evidence from studies of children of mothers who were exposed to DES (Diethylstilbestrol) in early pregnancy and experimental evidence from administration of synthetic estrogens to pregnant animals, it was hypothesised that environmental hormone disrupters, which have been demonstrated to be ubiquitously distributed, could play an aetiological role.