Preoperative testosterone and follicle stimulating hormone levels are important predictors for sperm retrieval by microdissection testicular sperm extraction in non‐mosaic Klinefelter syndrome

This study aimed to assess outcomes of microdissection testicular sperm extraction (MD‐TESE) and identify predictors for sperm retrieval (SR) in patients with non‐mosaic Klinefelter syndrome (NM‐KFS). We retrospectively evaluated 37 patients with NM‐KFS who underwent MD‐TESE. Data of age at operation, body mass index (BMI), testicular volume, serum luteinizing hormone (LH), follicle stimulating hormone (FSH), preoperative and postoperative testosterone levels with reduction ratio between the two values, and FSH/preoperative testosterone ratio were analysed. These patients were divided into two groups according to success or failure of SR: the successful and failure groups. Factors related to SR were evaluated by statistical analyses using the Mann–Whitney U test and logistic regression modelling. Regarding these factors, the cut‐off level was specified using the receiver operating characteristics (ROC) curve. Moreover, the percentage of SR at that level was assessed. A simple scoring model was developed based on the multivariate analysis. Fourteen patients underwent successful SR, whereas 23 experienced failure SR. Statistical analysis found preoperative testosterone and FSH levels to be significant factors associated with SR. On the ROC curve, the cut‐off levels for preoperative testosterone and FSH were 2.34 ng/ml and 33.2 mIU/ml respectively. A new scoring model was developed, consisting of preoperative testosterone (≥2.34 ng/ml) and FSH (≤33.2 mIU/ml). The sperm retrieval rates (SRRs) were clearly discriminated by stratification according to the scoring model. The SRR of the cases of scores of 2, 1 and 0 were 87.5%, 31.6% and 10% respectively. At our hospital, the SRR of MD‐TESE in patients with NM‐KFS was 37.8%. The patients with high testosterone and low FSH levels tended to demonstrate successful SR.