Fertility in men with Klinefelter's syndrome.

Patients with a Klinefelter syndrome (KS), defined by a 47 XXY karyotype, were long considered infertile. Testicular sperm extraction (TESE) now allows them to access fatherhood. We will present the data of studies since first experiment of TESE. Several factors influencing TESE outcome were proposed in these different studies. Among them, clinical and hormonal parameters have reported by few studies, age has been one of the most discussed prognostic factor of positive sperm retrieval rate. Data seems to show that TESE carried out before an age greater than 30 has a poorer prognosis for positive sperm retrieval. In few studies performed in younger patient, before 20 years, SRR was closed to result for 20 to 30 year old patients. Offering a TESE before 16 years old does not improve positive sperm extraction rate. In fact, the few studies carried out before the age of 16 were of poorer prognosis, most often linked to insufficient maturation of the residual gametes. In addition, androgen therapy, frequently prescribed in case of Klinefelter syndrome, did not seem to show any effect on sperm retrieval but only few studies were interested in the possible impact of this treatment. In conclusion, further studies are necessary to determine the interest of new markers to predict the chance of sperm retrieval, taking into account age, hormonal therapy.