Evidence for Increasing Incidence of Abnormalities of the Human Testis: A Review

Abstract

Recent reports have suggested that the incidence of genitourinary abnormalities in human males has increased during the past 50 years, including congenital abnormalities such as cryptorchidism and hypospadia, which seem to be occurring more commonly. Also, the incidence of testicular cancer has increased 3-to 4-fold since the 1940s. This increase seems to be worldwide including countries with a very high frequency of testicular neoplasia as well as those in which this cancer is rather uncommon. It has also been postulated that semen quality has been decreasing for the last half century. A recent study showed that the average sperm density has decreased significantly from 113 million/mL in 1940 to 66 million/mL in 1990. The mean seminal volume has also declined, indicating that the decrease in the total sperm count is even more pronounced than the fall in sperm density would indicate. The remarkable increase in frequency of testicular abnormalities over a relatively short period of time may be due to environmental rather than genetic factors. There is an epidemiological link between the occurrence of different testicular abnormalities. Therefore, common prenatally acting etiological factors with adverse effects on the fetal male gonad might be suspected. However, postnatal influences may also have a deleterious effect on male fertility. From the reproductive point of view, an increased impact on the human male gonad is of concern.

Socio-psycho-behavioural factors associated with male semen quality in China: results from 1346 healthy men in Chongqing

“…For example, some studies observed that tight-fitting underwear had an adverse effect on various semen parameters18–19, whereas other studies reported no adverse effect of tight-fitting underwear on semen quality 20 21. The present study did not observe that wearing tight-fitting underwear was significantly associated with semen quality but did find that wearing fibre underwear often lowered the percentage of normal sperm morphology (p=0.001) in men living in Chongqing after adjusting for confounders.…”

“…Similarly, the present study did not establish any relationship between regular exercise and semen parameters in men living in the Chongqing area. The impact of a sedentary lifestyle and having saunas on semen quality has attracted interest from researchers but the results have been inconsistent 10 19–21 24–28. The present study observed no significant association between a sedentary lifestyle or taking saunas and semen quality.…”

“…Although some studies observed that intensive exercise in athletes resulted in a decline in sperm density, motility and morphology,22 23 one study20 that focused on exercise in ordinary men did not find a significant association between physical exercise and any semen parameters. Similarly, the present study did not establish any relationship between regular exercise and semen parameters in men living in the Chongqing area.…”

Undesended testis: How extensive should the work up be?

“…Giwercman et al (1993) in their reports have suggested that the incidence of genitourinary abnormalities in human males has increased during the past 50 years, including congenital abnormalities such as cryptorchidism and hypospadias, which seem to be occurring more commonly. The increase in these abnormalities over a relatively short period of time may be due to the environmental rather than genetic factors.…”

“…From the reproductive point of view, an increased impact on the human male gonad is of concern. [1] About 90% of undescended testes are associated with an occult inguinal hernia, especially those with minimal descent and those associated with epididymal abnormalities. Ectopic testes are associated with an inguinal hernia in about 50% of cases.…”