Abstract
OBJECTIVE: To demonstrate the relationship between ultrasound (US) changes in seminiferous tubules during gonadotropin replacement therapy and spermatogenic progression in patients with azoospermia because of hypogonadotropic hypogonadism (HH). DESIGN: Retrospective observational study. SUBJECTS: Ten patients from 2 private male infertility clinics in Japan with azoospermia because of HH received human chorionic gonadotropin (hCG) + recombinant follicle-stimulating hormone replacement (rFSH). EXPOSURE: Gonadotropin treatment with hCG and rFSH. MAIN OUTCOME MEASURES: Semen analysis and US evaluation of seminiferous tubules. RESULTS: After the initial treatment with hCG alone, hCG and rFSH were administered by self-injection. Sperm appeared within the ejaculate in 9 of the 10 patients treated with gonadotropin replacement therapy. Thick seminiferous tubules, defined as >300 μm in diameter on the US image, were observed just before the first sperm appeared in the ejaculate. Furthermore, an increased density of thickened seminiferous tubules, as observed on US, corresponded to higher sperm counts in the ejaculate. CONCLUSION: Among patients with HH, a strong correlation was observed between the degree of spermatogenesis stimulated by gonadotropin and the alterations observed in the US images of their seminiferous tubules. To our knowledge, this is the first report demonstrating alterations in spermatogenesis as intratesticular morphological changes, specifically enlargement of seminiferous tubules, by US imaging.