Age as a Limiting Factor for Successful Sperm Retrieval in Nonmosaic Klinefelter Syndrome

Abstract

Intracytoplasmic sperm injection (ICSI) now permits fertilization of eggs using very small numbers of spermatozoa. Improvements in testicular sperm extraction (TESE) techniques have expanded indications from oligozoospermia to nonobstructive azoospermia. Klinefelter syndrome, which accounts for 5% of the latter cases, is characterized by sterility caused by lack of spermatogenesis. Isolated foci of spermatogenesis have been found in involved testes, explaining the rare cases of sperm production with appearance in the ejaculate. Several institutions perform TESE using either ordinary testicular biopsy techniques or meticulous microdissection to retrieve spermatozoa for ICSI. The reported success rate for TESE in patients with Klinefelter syndrome is 56%, but no predictive factors have been identified given the paucity of cases in each report. We analyzed results of TESE to elucidate success determinants for TESE in patients with Klinefelter syndrome. Retrospective analysis of microdissection TESE in nonmosaic Klinefelter syndrome patients. A collaborative study with three institutions. Eighty-four patients with nonobstructive azoospermia related to nonmosaic Klinefelter syndrome underwent TESE. To determine factors affecting successful sperm retrieval by TESE in patients with nonmosaic Klinefelter syndrome medical record were analyzed retrospectively. Correlations 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 were investigated. We succeeded in obtaining spermatozoa in 51 patients and failed in 33. LH, FSH, T, and testicular volume did not differ between patient groups defined by success and failure. Median ages for successful and failed TESE were 32.6 and 37.1, respectively (p<0.001). When we analyzed success rates of testicular sperm extraction for 5-year age brackets, the ratio of successful recovery of spermatozoa to failure decreased beyond 35 years. Testicular sperm extraction should be recommended before the critical age of 35 in nonmosaic Klinefelter syndrome patients.