A Case of Suspected Isolated Follicle-Stimulating Hormone (FSH) Deficiency Where Spermatogenesis Was Acquired by Human Menopausal Gonadotropin (hMG)

Isolated follicle-stimulating hormone (FSH) deficiency is a rare cause of infertility in both sexes, and only a few cases have been reported in Japan. This is a case report of a young male patient with isolated FSH deficiency and azoospermia who was successfully treated with human menopausal gonadotropin (hMG). A 28-year-old male patient was referred for azoospermia. The delivery at his birth was uneventful and a family history of infertility or hypogonadism was not observed. The testes volume was 22/24 mL (right/left). No varicocele was observed in the ultrasound, and no sign or symptom of hypogonadism was found. In the semen analysis, however, the sperm concentration was as low as 2.5×106/mL and the motility was less than 1%. The endocrine panel revealed luteinizing hormone (LH) (2.1 mUI/mL, normal values 0.8-5.7 mUI/mL) and testosterone (6.57 ng/ml, normal values 1.42-9.23 ng/mL) were normal, while the FSH level was very low (0.6 mUI/mL, normal values 2.0-8.3 mIU/mL). The odor and the karyotype 46, XY, were normal. The brain MRI scans showed no abnormal findings. Genitalia and potency were normal. The diagnosis was made of isolated FSH with severe oligoastenozoospermia clinically. FSH replacement therapy was employed. The patient self-injected 150 units of hMG three times a week. After 3 months of the treatment, the sperm concentration and motility went up to 264×106/mL and 12%, respectively. At 5 months, the patient’s spouse conceived naturally, and at 7 months the treatment was terminated. During the treatment, FSH rose to the normal range, while other test items showed no change. The patient’s health condition was uneventful. The spouse delivered a healthy boy. In conclusion, for isolated FSH with severe oligoastenozoospermia, hMG can be as effective as recombinant human FSH (rh-FSH), although the dosage remains a matter of discussion.