Age as a limiting factor for successful sperm retrieval in patients with nonmosaic Klinefelter's syndrome.

OBJECTIVE: To determine factors affecting successful sperm retrieval by testicular sperm extraction in patients with nonmosaic Klinefelter's syndrome.

DESIGN: Medical record analysis for nonmosaic Klinefelter's syndrome patients who underwent testicular sperm extraction.

SETTING: Three university-based tertiary centers.

PATIENT(S): Fifty-one patients with nonobstructive azoospermia related to nonmosaic Klinefelter's syndrome.

INTERVENTION(S): Testicular sperm extraction.

MAIN OUTCOME MEASURE(S): Correlation of patient characteristics; serum concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T); as well as testicular volume with success in testicular sperm extraction.

RESULT(S): We succeeded in obtaining spermatozoa in 26 patients and failed in 25. Levels of LH, FSH, and T and testicular volume did not differ between patient groups defined by success and failure. Median ages for successful and failed testicular sperm extraction were 31 and 38 years, respectively (statistically significant difference). When we analyzed success rates of testicular sperm extraction between two patient groups (<35 and > or =35 years old), the percentage of successful recovery of spermatozoa decreased after the age of 35 years (statistically significant difference).

CONCLUSION(S): Testicular sperm extraction should be recommended before the critical age of 35 years.