Prior testosterone replacement therapy may impact spermatogenic response to combined gonadotropin therapy in severe congenital hypogonadotropic hypogonadism.

objectiveTo study the effect of prior testosterone replacement therapy (TRT) on the spermatogenic response to combined gonadotropin therapy (CGT) in severe and partial phenotype congenital hypogonadotropic hypogonadism (CHH) patients.

designRetrospective cohort study.

settingTertiary care center. PATIENTS: Patients of CHH without (n = 17) and with prior TRT (n = 18) were subdivided into severe and partial groups, based on mean testicular volume ≤ 3 cc and > 3 cc respectively.

interventionParticipants were treated with hMG at a dose of 75-150 U 3/week and gradually escalating doses of hCG until maximum dose (2000 U 3/week or 5000 U 2/week) or serum total testosterone of ≥ 3.5 ng/ml was reached.

main outcome measuresFinal mean TV, trough serum testosterone (T), sperm concentration

resultsThirty-five patients (20 severe, baseline mean TV of 3.6 ± 2.7 ml) were started on CGT at 24.8 ± 6.1 years. The median duration of prior TRT was 38 (IQR 10-63.75) months in the exposed group. After 33 ± 12 months, final mean TV was 8.9 ± 5.5 ml, 86% achieved serum testosterone > 3.5 ng/ml and 70% achieved spermatogenesis [median 5 (0-12.6) million/ml]. Patients without prior TRT had significantly higher peak sperm count than those with prior- TRT (median 9 vs 0.05 million/ml, p = 0.004). This effect of prior TRT was more pronounced in severe phenotype patients (median 7 vs 0 million/ml, p = 0.01).

conclusionPrior-TRT may interfere with spermatogenic response to CGT in CHH patients, especially in those with a severe phenotype.