Gonadotropin Therapy Once a Week for Spermatogenesis in Hypogonadotropic Hypogonadism

Hypogonadotropic hypogonadism (HH) can be caused by congenital HH (CHH), pituitary stalk interruption syndrome (PSIS), and pituitary injury (acquired HH). Gonadotropin therapy, typically administered every other day or twice a week, is commonly used to promote spermatogenesis. The aim of this retrospective study was to evaluate the efficacy of weekly gonadotropin therapy on spermatogenesis in patients with HH (n = 160).The patients' diagnoses include Kallmann syndrome (KS) (n = 61), normosmic CHH (nCHH) (n = 34), PSIS (n = 48), and acquired HH (n = 17). The rate of successful spermatogenesis and median time to achieve spermatogenesis among these 4 subgroups were compared as well as between a weekly group (n = 95) and a twice-a-week group (n = 223) of CHH patients.Once-a-week gonadotropin therapy resulted in 74% (119/160) of HH patients achieving spermatogenesis with significantly increased testicular volume and total testosterone levels (P < .001). The median period of spermatogenesis was 13 (interquartile range[IQR] 11.4-14.6) months. Larger basal testicular volume (P = .0142) was an independent predictor for earlier sperm appearance. Six spontaneous pregnancies occurred. Compared with the twice-a-week regimen for spermatogenesis, the weekly injection group had a similar median time of sperm appearance (14 [IQR, 11.6-16.4] vs 15 [IQR, 13.5-16.5] months), success rate (78% [74/95] vs 64% [143/223]), sperm concentration (20.9 [IQR, 5.0-46.3] vs 11.7 [IQR, 2.1-24.4] million/mL), and progressive sperm motility (40.8 ± 27.3% vs 36.9% ± 20.2%).Weekly gonadotropin therapy is effective in inducing spermatogenesis, similar to that of twice-a-week therapy. A larger basal testicular size was a favorable indicator for earlier spermatogenesis.