Testicular histology related to fertility outcome and postpubertal hormone status in cryptorchidism.

BACKGROUND: Early surgical correction of an undescended testis is performed to prevent the development of male infertility. However, in boys with cryptorchidism early successful surgery cannot prevent infertility if they lack Ad spermatogonia. In this study, sperm concentrations and postpubertal hormone levels were correlated to bilateral testicular histology. The aim was to define the risk of future infertility via a testis biopsy program for boys with cryptorchidism.

METHODS: Eighty-nine boys who had an orchidopexy were subjected to bilateral testicular biopsy. Histological analysis of 178 biopsies indicated three groups of high, intermediate, and low risk of infertility according to the presence of Ad spermatogonia. After puberty, sperm concentrations were analysed and correlated with plasma gonadotropin and testosterone levels.

FINDINGS: In patients with unilateral cryptorchidism 70% of scrotal testes had an impaired transformation of Ad spermatogonia, indicating that cryptorchidism is a bilateral disease. Sperm concentrations correlated to the number of Ad spermatogonia found at the time of orchidopexy (p<0.001). All males in the high risk of infertility group were oligospermic (mean: 8.9 x 10 (6) sperm/ejaculate) and 20% were azoospermic. These patients had 25 times less sperm compared to the group with presence of Ad spermatogonia in both testes (p<0.001). Correlations between testicular histology and postpubertal hormone levels confirmed a relative gonadotropin deficiency in the majority of males with cryptorchidism.

INTERPRETATIONS: Ad spermatogonia proved to be a discriminating factor for the fertility outcome in cryptorchidism. Gonadotropin treatment following orchidopexy should be considered in cryptorchidism when no Ad spermatogonia are found in undescended gonads and scrotal testis have Ad germ cell counts <0.005 per tubule.