Is genetic fatherhood within reach for all azoospermic Klinefelter men?

Background Multidisciplinary management of Klinefelter cases is now considered good clinical practice in order to ensure optimal quality of life. Reproductive performance of Klinefelter men is an important issue however literature in this domain is limited and prone to bias. Study design This was a retrospective longitudinal cohort study performed at a tertiary referral University Centre for Reproductive Medicine and Genetics. One hundred thirty-eight non-mosaic azoospermic Klinefelter patients undergoing their first testicular biopsy (TESE) between 1994 and 2013, followed by intracytoplasmic sperm injection (ICSI) with fresh or frozen-thawed testicular sperm in the female partner, were followed-up longitudinally. The main outcome measure was cumulative live birth rate per Klinefelter patient embarking on TESE-ICSI. Findings In forty-eight men (48/138) sperm were successfully retrieved at the first TESE (34.8%). The mean age of the patients was 32.4 years. Younger age at first TESE was associated with a higher sperm retrieval rate (p<0.001). Overall 39 couples underwent 62 ICSI cycles and 13 frozen embryo transfer cycles resulting in in 20 pregnancies and 14 live birth deliveries (16 children). The mean age of the female partner was 28.1 years. The crude cumulative delivery rate after four ICSI cycles was 35.9%. Per intention-to-treat however, only 10.1% (14/138) of the Klinefelter men starting treatment succeeded in having their biologically own child(ren). Conclusion Non-mosaic Klinefelter patients with azoospermia seeking treatment by TESE-ICSI should be counseled that by intention-to-treat the chance of retrieving sperm is fair, however only a minority will eventually father genetically own children.