<b>Development of a Predictive Nomogram for Testicular Sperm Extraction Outcomes in Non-Obstructive Azoospermia Patients Using Testicular Volume, Follicle-Stimulating Hormone, and Testosterone Levels as Key Parameters</b>

Objective: To investigate the establishment of a predictive model for the outcomes of testicular sperm extraction (TESE) surgery in patients with non-obstructive azoospermia (NOA). Methods: We conducted a retrospective analysis of patients who visited the andrology outpatient clinic at the First Affiliated Hospital of Soochow University from January 2010 to January 2024. A total of 425 patients’ clinical data were included in the study. All patients underwent TESE surgery, with 216 cases in the sperm-positive group and 209 cases in the sperm-negative group. Differences in testicular volume, reproductive hormone levels, and clinically relevant parameters between the two groups were compared. Multivariate logistic regression analyze was performed to identify independent risk factors, which were then used to establish a predictive nomogram model. The model’s goodness-of-fit was evaluated using a calibration curve. The diagnostic effectiveness of the model was assessed through the receiver operating characteristic (ROC) curve, while the net benefit was evaluated using a decision curve analysis (DCA) plot. Results: Univariate analysis revealed that serum follicle-stimulating hormone (FSH), body mass index (BMI), seminal plasma fructose, elastase levels, and testicular microlithiasis differed significantly between the two groups (p&lt;0.05). Logistic multivariate regression analysis of these factors found FSH, testicular volume, and testosterone (T) to be independent risk factors affecting TESE outcomes. Specifically, FSH was negatively correlated (OR=0.905, 95% CI: 0.876-0.935, P&lt;0.001), while testicular volume (OR=1.453, 95% CI: 1.328-1.591, P&lt;0.001) and T (OR=1.326, 95% CI: 1.098-1.601, P=0.003) were positively correlated. A predictive nomogram was established using parameters of testicular volume, FSH, and T. The calibration curve demonstrated good fit, and the area under the ROC curve was 0.879, indicating high accuracy of the model. The DCA plot showed that the model has substantial clinical benefit. Conclusion: In NOA patients, low testicular volume, low T levels, and high FSH levels are independent risk factors for unsuccessful TESE sperm retrieval. The predictive model nomogram based on testicular volume, serum FSH, and T levels provides excellent predictive power for positive outcomes in testicular sperm extraction.