Restoration of spermatogenesis in a male with prolactinoma-induced hypogonadotropic hypogonadism using follitropin delta and recombinant choriogonadotropin alfa: a case report.

BACKGROUND

Follitropin delta is a recombinant human follicle-stimulating hormone (FSH) produced in the human PER.C6 cell line, approved exclusively for controlled ovarian stimulation in women. Its unique glycosylation profile confers distinct pharmacokinetic advantages over Chinese hamster ovary-derived follitropin alfa. To date, no published report exists on the use of follitropin delta in males. The present case describes the first successful off-label use of follitropin delta in combination with recombinant choriogonadotropin alfa (hCG) to restore spermatogenesis in a male patient with prolactinoma-induced hypogonadotropic hypogonadism and exogenous testosterone-associated azoospermia.

CASE REPORT: A 30-year-old male with a 6-cm pituitary prolactinoma diagnosed at age 18, managed with cabergoline, presented with azoospermia following 2 years of testosterone undecanoate replacement therapy. There was confirmed suppression of gonadotropins (luteinizing hormone 0.3 mIU/mL and FSH 0.3 mIU/mL) and prolactin of 100 ng/mL. Hormonal stimulation was initiated with follitropin delta 10 µg twice weekly and hCG alfa (~ 125 µg every 4-5 days), alongside continued cabergoline. After 4 months of therapy, semen analysis revealed sperm concentration of 3.5 million/mL (total sperm count 4.9 million/ejaculate). Testosterone levels normalized, with marked clinical improvement.

CONCLUSION

This case provides the first evidence that follitropin delta can successfully replace conventional FSH preparations in male gonadotropin stimulation protocols. Spermatogenesis was restored within a favorable timeframe, enabling access to assisted reproductive technology (IVF/ICSI). Nevertheless, these findings are limited to a single case report and require confirmation in larger studies.