Hormone Therapy for Undescended Testicle: When Are hCG and GnRH Used?

Two drug classes have been used. hCG (human chorionic gonadotropin) is given as an intramuscular injection and stimulates the testicle to produce testosterone; GnRH (gonadotropin-releasing hormone) is given as a nasal spray and aims for the same effect indirectly, by stimulating the pituitary gland.

In systematic reviews and a Cochrane analysis, the rate of permanent descent with hormone therapy is low — reported in the literature at roughly one in five — and its advantage over placebo is limited. Some of the testicles that do descend also re-ascend within months.

hCG therapy can cause puberty-like changes, even if temporary: growth of the penis and scrotum, skin flushing, increased hair growth, irritability, and pain at the injection site. These regress once treatment is stopped.

• More controversial are the possible effects of hCG on testicular tissue: some studies have reported inflammatory changes and cell loss in germ cells after treatment. These findings are not conclusive, but they have called into question the assumption of a ‘harmless trial’ and are one of the reasons for the guidelines’ cautious stance.

Hormone therapy also has a different use: not to bring the testicle down, but to support the maturation of the germ cells within it. In bilateral undescended testicle, sperm parameters and the paternity rate are markedly lower in adulthood; germ cell loss is more severe in this group.

Hormone therapy is discussed openly as an option in consultations with families; however, in a unilateral case, our recommendation is orchiopexy within the target window. Surgery both brings the testicle into the scrotum, closes any accompanying hernia sac, and allows the testicle’s condition to be seen directly.

• Unilateral undescended testicle, palpable or non-palpable: hormone therapy is not recommended for descent; orchiopexy is planned
• Retractile testicle: no treatment needed, monitored once a year
• Bilateral undescended testicle: orchiopexy takes priority; endocrine support for reproductive potential is considered in selected cases
• Bilateral non-palpable testicle: endocrine, and if needed genetic, evaluation before surgical planning

• In bilateral or selected cases where endocrine support comes under consideration, the decision in our practice is made jointly with pediatric endocrinology; follow-up continues with the same team through adolescence and adulthood, with hormone and semen evaluation when needed.