The importance of mini-puberty for fertility in cryptorchidism

Purpose: Mini-puberty is the hormonal surge of gonadotropins and testosterone which occurs in early infancy. It induces the development and transformation of gonocytes into Ad spermatogonia, which is impaired in many cryptorchid testes. We examine the role of testosterone in the transformation and development of Ad spermatogonia. Materials and Methods: A total of 32 patients 1 to 7 years old were treated with human chorionic gonadotropin (HCG) to achieve epididymo-testicular descent before orchiopexy (group 1), and 33 patients underwent orchiopexy without previous hormonal treatment (group 2). A testicular biopsy was obtained during surgery from all the patients. The number of Ad spermatogonia per tubular cross section (Ad/tbx) was assessed and compared between the 2 groups. The number of Ad spermatogonia per tubular cross section in group 1 was also correlated with the post-stimulatory testosterone plasma values. Results: In group 1, 17 patients had greater than 0.1 Ad/tbx, and the remaining patients had 0.1 or less Ad/tbx. In group 2, 6 patients had greater than 0.1 Ad/tbx. Of the boys with cryptorchidism 35% responded inadequately to HCG stimulation, while 10% did not respond. Those patients with suboptimal Leydig cell capacity (and an inadequate response to HCG stimulation) had a defective Ad spermatogonia differentiation of 0.1 or less. Conclusions: Boys with cryptorchidism with an insufficient testosterone surge after HCG risk infertility despite early and successful surgery. The testicular biopsy assists in identifying those who might benefit from hormonal treatment following successful orchiopexy.