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.

A diminished postnatal surge of Ad spermatogonia in cryptorchid infants is additional evidence for hypogonadotropic hypogonadism.

BACKGROUND: The aim of this study was to describe the development of Ad spermatogonia in both unilateral and bilateral cryptorchid infants compared to a control population of comparable age and to note particularly the fate of Ad spermatogonia during the normal surge of testosterone and gonadotropin. METHODS: The incidence and development of Ad (dark) adult type of spermatogonia were assessed in 270 testicular biopsies from 159 cryptorchid infants at 1-12 months of age. These results were compared to the control population of the same age. RESULTS: The number of Ad spermatogonia increased markedly after five months of life in the control population. The scrotal testes of unilateral cryptorchid infants also had an increase in the number of Ad spermatogonia but it was distinctly lower than that of the control population. In contrast, this surge was completely absent in the cryptorchid testes. The number of Ad spermatogonia in unilateral cryptorchid testes correlated in a nonlinear fashion with those in the contralateral scrotal testes. The total number of germ cells in the cryptorchid testes in the first six months of life is normal, after which time it declines rapidly. CONCLUSION: The impaired transformation of germ cells into Ad spermatogonia in both unilateral and bilateral cryptorchid infant testes during mini-puberty underscores the importance of hypogonadotropic-hypogonadism in the pathogenesis of this disease.