Objective: This study aimed to describe a distinct subpopulation of azoospermic patients with isolated elevation of follicle-stimulating hormone (iFSH) and poor outcomes of microdissection testicular sperm extraction (microTESE).
Methods: A retrospective analysis of microTESE outcomes was conducted among 565 patients with non-obstructive azoospermia (NOA). Testicular pathology was assessed by the dominant histological pattern and Bergmann-Kliesch score (BKS). Descriptive statistics were presented for the iFSH subgroup. Inhibin B levels, the sperm retrieval rate (SRR), and BKS were compared in iFSH patients and other NOA patients.
Results: The overall SRR was 33.3% per microTESE attempt. The median BKS was 0.6 (interquartile range, 0-2). Of all NOA patients, 132 had iFSH, and microTESE was successful only in 11 of those cases, with an SRR of 8.3%, while the total SRR in other NOA patients was 38.1% (p<0.001). iFSH had a sensitivity of 32.1% (95% confidence interval [CI], 27.4%-36.8%) and specificity of 94.1% (95% CI, 90.8-97.5%) as a predictor of negative microTESE outcomes.
Conclusion: Patients with iFSH may harbor a distinct testicular phenotype with total loss of the germ cell population and poor outcomes of surgical sperm retrieval.
Keywords: Azoospermia; Follicle-stimulating hormone; Male infertility; Sperm retrieval.