Urology (Reproductive Health and Treatments)

UNDESCENDED TESTIS AND INFERTILITY

HISTOLOGICAL CHANGES

An undescended testis shows normal histological structure from birth until one year of age. The earliest finding is hypoplasia of Leydig cells (cells producing testosterone), which can be observed from the first month onward. After 18 months, a decrease in the number of Leydig cells, degeneration in Sertoli cells, delayed maturation of gonocytes, and a decrease in the diameter of the tubules within the testis are observed. The higher the position of the testis, the greater the histopathological deterioration. In cases of ascending testis, milder and later-onset changes are also observed.

In untreated cases persisting into advanced age, fertility deteriorates and the risk of malignancy (cancer) increases. Nearly all untreated bilateral undescended testis cases result in infertility.

The incidence of testicular tumors in the general population is 1/100000. This rate increases 40-fold to 1/2500 in cases with undescended testis. Evidence regarding whether surgical treatment reduces tumor development is controversial; however, the aim is to position the testis in a location that allows easier examination and early diagnosis.

TREATMENT

In cases of undescended testis, surgical treatment should be carefully performed before one year of age without causing damage to the testis. In other words, the testes should be lowered into the scrotum before the age of one.

Hormonal treatment is not commonly preferred today due to its low success rates and side effects.

UNDESCENDED TESTIS AND INFERTILITY

Fertility is the primary goal in the treatment of undescended testis. Over the past 20–30 years, significant evidence has emerged showing that undescended testis causes damage to germ cell development. Today, there are two main views regarding infertility caused by undescended testis. According to the classical first view, because the testis is located outside the scrotum, the negative effects of heat especially affect germ cells over time. Histopathological germ cell damage occurring in untreated undescended testis cases over time supports this view.

The second view is that undescended testis is actually an endocrinopathy, and the main problem related to infertility is the insufficiency in the transformation of gonocytes (sperm precursors), which are the fetal germ cell reservoir, into adult dark-type spermatogonia due to gonadotropin (hormonal) factors. The possibility of problems occurring in the opposite testis also supports this view.

In light of current data, studies conducted in rats have shown that early surgical treatment reduces germ cell damage. Studies in azoospermic men have demonstrated the effect of undescended testis on fertility. While the rate of azoospermia is 89% in untreated bilateral undescended testis cases, this rate is much lower in treated cases. It is known that all children with undescended testis have germ cells in their testes at birth. The decrease in the number of these germ cells begins as early as the sixth month and varies according to the position of the testis. The first sharp decline in germ cell count is seen at 1.8 years of age. In children aged 8–9 months with undescended testis, the germ cell count is at a critically low level, and this information indicates that surgical treatment should be performed before this period.

In summary, considering all this information about undescended testis:

The treatment of true undescended testes that do not descend by one year of age is surgical.
The use of hormonal treatment to lower the testis is gradually losing support.
Since the chance of spontaneous descent after the sixth month following birth is very low, the most appropriate period for intervention appears to be between 6–12 months.
In unilateral cases treated with orchiopexy surgery (descent surgery) at the appropriate time, fertility potential can be considered close to normal.
A certain group of retractile testes (moving up and down) may fail to descend and become an “ascending testis.” These cases should be followed regularly and treated if non-descent occurs.
All families with male children should check their children’s testes, and if they cannot palpate the testis in the scrotum, they should definitely consult a urology specialist.