Multiple semen analyses are important for identifying patients with severe oligozoospermia or cryptozoospermia. Moreover, clinical predictive factors for cryptozoospermia and severe oligozoospermia are warranted. Therefore, we aimed to identify predictors of sperm retrieval in patients with a prior diagnosis of non-obstructive azoospermia based on repeat semen analysis. We retrospectively included 209 patients diagnosed with non-obstructive azoospermia. Data regarding age at diagnosis
body mass index
testicular volume
serum luteinizing hormone, follicle-stimulating hormone, and testosterone levels
smoking history
and testicular microlithiasis were analyzed. Patients were classified into the falsely reported azoospermia (FAZO) and true azoospermia (TAZO) groups. Furthermore, FAZO-related factors were evaluated using the Mann-Whitney U test, as well as univariate and multivariate analysis logistic regression models. Regarding FAZO-related factors, the cut-off level was determined using receiver operating characteristic curve analysis. Among 209 patients with non-obstructive azoospermia, 33 (15.8%) had spermatozoa identified in subsequent semen analyses. Multivariate analysis revealed that the FAZO group had significantly lower follicle-stimulating hormone levels than the TAZO group. Receiver operating characteristic curve analysis showed that the cut-off value for the follicle-stimulating hormone level was 15.3 mIU/mL, with 26 (78.8%) and 29 (16.5%) patients in the FAZO and TAZO groups, respectively, having follicle-stimulating hormone levels ≤15.3 mIU/mL. In conclusion, the follicle-stimulating hormone level was a predictive factor for FAZO. In patients diagnosed with azoospermia who have relatively low follicle-stimulating hormone levels, multiple semen analyses might facilitate identification of sperm in ejaculated semen.