Prediction of Successful Sperm Retrieval in Patients with Nonobstructive Azoospermia

Our aim was to evaluate the predictive values of factors that indicate successful sperm retrieval in men with nonobstructive azoospermia. We evaluated 85 infertile men with nonobstructive azoospermia who underwent multiple bilateral testicular biopsies. Factors including age, infertility period, surgical history, testicular volume, testicular consistency, serum follicle-stimulating hormone (FSH), serum inhibin B, serum luteinizing hormone, and serum total testosterone were assessed in relation to sperm retrieval results. Spermatozoa were retrieved in 18 biopsies (21.2%). Follicle-stimulating hormone, serum inhibin B, and testicular volume were associated with the results of sperm retrieval. Men with a higher testicular volume, a higher serum inhibin B, and a lower FSH had successful sperm retrieval. The cutoff points were determined as 9.5 mL for testicular volume, 9.9 IU/L for serum FSH, and 39.8 pg/mL for serum inhibin B. These 3 factors had strong correlations with each other. The sensitivities and specificities were 88.9% and 94% for testicular volume, 97% and 83.3% for FSH, and 72.2% and 95.5% for serum inhibin B, respectively. The positive predictive value for a combination of serum FSH and inhibin B was 100%. Serum FSH and serum inhibin B are useful markers for evaluation of the presence of sperm in patients with nonobstructive azoospermia. Inhibin B has a high specificity when combined with serum FSH and their measurements can be helpful in all patients with nonobstructive azoospermia before decision making for sperm retrieval.