Evaluation of Azoospermic Patients to Distinguish Obstructive from Non-Obstructive Azoospermia, and Necessity of Diagnostic Testis Biopsy: A Retrospective Study

Background: Accurate etiology of azoospermia is required for optimal management of patients. The aim of this study was the determination of serum hormonal levels and testicular long axis cut off points to distinguish obstructive azoospermia (OA) from non-OA (NOA) in Iranian patients as well as the evaluation of the necessity of diagnostic testis biopsy in azoospermic patients. Materials and Methods: In this retrospective study, data of 471 azoospermic patients such as history and physical examination, serum hormonal level, semen fluid parameter, and testicular long axis based on ultrasound were evaluated from 2016 to 2020. All patients were examined by a single urologist and underwent a diagnostic testis biopsy for a definite diagnosis. The diagnostic parameters were analyzed using Statistical Package for the Social Sciences (SPSS) version 16 with t test and chi-square test and receiver operating characteristic (ROC) curves to distinguish NOA from OA. Results: A total of 127 patients with OA and 284 with NOA were included in this study. The mean serum testosterone level was significantly higher in OA than NOA (4.2 vs. 3.4 ng/ml), whereas the mean serum follicular stimulating hormone (FSH, 5.3 vs. 19.1 mIU/ml) and luteinizing hormone (LH, 5.3 vs. 11 mIU/ml) were lower in OA. ROC curve analysis showed that FSH and testicular long axis were the best diagnostic predictors. Using a combination of serum FSH (8.9 mIU/ml) and testicular long axis (39 mm), the positive predictive value for NOA was 97.02% and for OA was 78.8%. Conclusion: Combination of serum FSH higher than 8.9 mIU/ml and testicular long axis lower than 39 mm were strong predictors to distinguish NOA from OA in Iranian participants in this study. In addition, diagnostic testicular biopsy seems to be necessary for patients with OA and NOA characteristics.