Received April 18, 2021
Accepted September 29, 2021

Objective: The current study aimed to present the clinical outcomes of 76 azoospermic patients with non-mosaic Klinefelter syndrome (KS), treated with testicular spermatozoa extraction (TESE) followed by intracytoplasmic sperm injection (ICSI) using either fresh or cryopreserved testicular spermatozoa. Methods: We retrospectively evaluated 76 patients with non-mosaic KS belonging to a special group of cases that besides infertility did not present the classical signs and symptoms of testosterone deficiency. Of these patients, one repeated the TESE procedure (76 patients, 77 TESE cycles). Of the patients, 60 accepted to perform TESE associated with ovarian stimulation, whereas 16 patients performed TESE followed by testicular spermatozoa cryopreservation. Aneuploidy screening of the offspring was performed by Multiplex ligation-dependent probe amplification and by amniotic fluid karyotyping. Statistical analysis used the Chi-Square Tests, Fisher Exact Test, 2-sided, for rates, and the Independent Samples T-test for equality of means, 2-sided. Results: Testicular spermatozoa were recovered in 31 (40.3%) of the attempts. These patients went 47 ICSI cycles, 25 with fresh testicular spermatozoa and 22 with cryopreserved testicular spermatozoa. The rates of fertilization (63.5% vs 41.6%, P=0.000), implantation (37% vs 13.2%, P=0.014), clinical pregnancy (60.9% vs 19%, P=0.005) and newborn (65.2% vs 23.8%, P=0.006) were higher with fresh testicular spermatozoa. Chromosome analysis of the 21 newborns was normal. Conclusions: The present data adds further information regarding the recovery rate of spermatozoa after TESE as for the embryological and clinical outcomes with fresh and cryopreserved testicular spermatozoa, besides reassuring the safety concerning chromosomal transmission to the children of Klinefelter fathers.