Therapy with human chorionic gonadotropin alone induces spermatogenesis in men with isolated hypogonadotropic hypogonadism: long term follow-up

The effects of long-term (14-120 months) hCG-treatment of 17 male patients affected by isolated hypogonadotrophic hypogonadism (IHH) on testicular volume, plasma testosterone levels, and sperm concentration were assessed. Mean testicular volume increased from 3.8 +/- 0.2 (Mean +/- SEM) ml to a maximal of 14.9 +/- 1.1 ml after 22.2 +/- 2.3 months of hCG treatment. Maximal testicular volume correlated positively with the volume recorded before the patients had undergone any previous treatment. Testicular growth was also analysed by sorting the patients into two sub-groups according to whether their initial testicular volume was less than 4 ml (small testis subset, STS) or greater than or equal to 4 ml (large testis subset, LTS), supposedly indicating complete or partial gonadotrophin deficiency, respectively. Testicular volumes in the LTS group were always greater than those of the STS. Plasma testosterone levels reached adulthood values during hCG treatment and no statistically significant difference was detected between LTS and STS patients with IHH. Thirteen patients (70%) became sperm-positive during treatment with hCG alone; five out of eight (60%) were STS patients and eight out of nine (90%) were LTS. In addition, LTS patients always had a greater sperm output than did STS patients. Sperm concentration correlated positively with maximal testicular volume, but not with patient age, length of treatment, or initial testicular volume. The administration of hMG to eight of these patients caused an increase in testicular volume in two patients but the mean volume was not statistically different from that recorded at the end of treatment with hCG alone. Similarly, sperm concentration improved in three patients but again it did not differ significantly from that achieved in the course of hCG treatment. It is noteworthy that one patient became sperm-positive after the addition of hMG to his therapeutic regimen. Among sperm-positive patients attempting conception, seven out of 10 succeeded, two of whom were from the STS group. In summary, this study indicates that hCG alone is an effective treatment to induce complete spermiogenesis in IHH patients regardless of their initial testicular volume. However, a number of IHH patients may benefit from the addition of hMG in terms of testicular volume, sperm output, and pregnancy outcome