Serum levels of inhibin B and follicle-stimulating hormone may predict successful sperm retrieval in men with azoospermia who are undergoing testicular sperm extraction.

To evaluate the predictive power for sperm retrieval in testicular sperm extraction of inhibin B and FSH levels in the peripheral blood in association with the testicular histology. Clinical study. Departments of andrology and urology at a university hospital.Fifty-two patients with azoospermia. Determination of serum levels of FSH and inhibin B in men with azoospermia. Testicular incision and histological investigation as well as testicular sperm extraction (TESE) followed by intracytoplasmic sperm injection were performed. Comparison of hormone levels with different histological features of seminiferous tubules (normospermatogenesis, hypospermatogenesis, and Sertoli cell-only syndrome) and TESE outcome.With respect to the histological proof of spermatozoa, the sensitivity of the FSH levels >10 mU/mL was 82%, and of inhibin B levels, <79 pg/mL, 78%; the specificity was 80% for both hormone levels. With respect to the successful sperm extraction in the TESE procedure, the sensitivity of the FSH levels was 58% and the specificity was 50%; and the sensitivity of inhibin B levels was 52.5% and the specificity was 60%. Inhibin B and FSH levels are correlated with spermatogenetic activity. The combination of the two parameters is currently the best predictor for the presence of sperm, which may be found in TESE. However, the prediction is not absolutely reliable: TESE can be also successful when both hormone levels are outside the threshold levels.