This study presents healthy births with two azoospermic nonmosaic Klinefelter’s syndrome patients using frozen-thawed testicular spermatozoa and frozen-thawed embryos. In the first couple, male partner underwent a diagnostic testicular sperm extraction (TESE). Spermatozoa were recovered and cryopreserved. Subsequent intracytoplasmic sperm injection (ICSI) cycle using the frozen-thawed testicular spermatozoa resulted in delivery of healthy female twins with normal karyotypes. The second couple underwent simultaneous TESE-ICSI cycle and after recovery of spermatozoa, twenty-one metaphase II oocytes were injected with testicular spermatozoa. Nineteen oocytes showed fertilization with two pronuclei. Ten embryos at pronuclear stage were frozen and the remaining nine were cultured for further cleavage. No pregnancy was obtained by the transfer of four fresh embryos on day three. Later, after endometrial preparation, ten embryos frozen at pronuclear stage were thawed and transfer of two grade 1 and two grade 3 embryos, resulted in delivery of a healthy girl with a normal karyotype. As a conclusion, it is possible to achieve pregnancies using frozen-thawed spermatozoa and embryos in cases with Klinefelter’s syndrome if spermatozoa are obtained.

Keywords: Klinefelter’s syndrome, testicular spermatozoa, frozen-thawed spermatozoa, frozen-thawed embryo