Abstract
Study question
What are the clinical results of patients with azoospermia and nonmosaic Klinefelter syndrome, using fresh and cryopreserved sperm?
Summary answer
The results showed a recovery rate of testicular sperm in the order of 40% and a life newborn rate of 52% when using fresh sperm
What is known already
In Klinefelter syndrome (KS), the rates of successful testicular sperm retrieval were shown to be similar either using conventional TESE or micro-TESE (Corona et al., 2017), which highlights that the variability observed between studies is due to differences in patient characteristics. There are a few works with a large number of KS patients elucidating the clinical outcomes using fresh and cryopreserved testicular sperm. However, these studies revealed contradictory outcomes, either revealing better (Greco et al., 2013; Vicdan et al., 2016) or worst (Madureira et al., 2014) results with cryopreserved testicular sperm, or finding no differences (Chen et al, 2019).
Study design, size, duration
This study includes all patients up to 2019 presenting azoospermia due to non-mosaic Klinefelter syndrome (n = 76) that went for infertility consultations in a private fertility clinic. Patients were evaluated by the same Urologist. The genetic analysis of the patients was performed at an academic institution. At examination patients did not refer other complaints besides infertility, and referred to have not received any hormone replacement therapy in the past.
Participants/materials, setting, methods
The 76 azoospermic patients with non-mosaic Klinefelter syndrome (KS) were treated by testicular sperm extraction (TESE) followed by intracytoplasmic sperm injection (ICSI), using fresh and cryopreserved testicular sperm. Most patients used fresh testicular sperm, where others preferred to postpone ICSI treatment cycles and used cryopreserved testicular sperm. Aneuploidy screening in children was performed by prenatal diagnosis and MLPA (Multiplex ligation-dependent probe amplification). Full embryological, clinical and newborn outcomes are provided.
Main results and the role of chance
Of the 76 patients with non-mosaic Klinefelter syndrome, one repeated the testicular sperm extraction (TESE) procedure. Testicular sperm were recovered in 31/77 (40.3%) of the cases. Comparisons between the 31 cases with successful sperm recover (group–1) and the 46 cases without a successful TESE (group–2) revealed no significant differences regarding age, time of infertility, testicular volume, serum levels of FSH, LH and testosterone, total number of testicular fragments analyzed, and time of search in samples. The mean male age was 34 years. In most of the cases, the testicular volume was reduced (96.1%), the levels of FSH (98.3%) and LH (94.1%) were increased, and the levels of testosterone were normal (77.6%). There were 25 intracytoplasmic sperm injection (ICSI) treatment cycles using fresh testicular sperm and 22 ICSI treatment cycles using frozen testicular sperm. The rates of fertilization (63.5% fresh sperm vs 41.6% frozen sperm), implantation (37% fresh sperm vs 13.2% frozen sperm), clinical pregnancy (60.9% fresh sperm vs 19% frozen sperm), live birth delivery (52.2% fresh sperm vs 19% frozen sperm) and newborn (65.2% fresh sperm vs 23.8% frozen sperm) were higher in the group using fresh testicular sperm. Chromosome analysis of the 21 newborn was normal.
Limitations, reasons for caution
Although presenting a high number of cases with azoospermic non-mosaic Klinefelter syndrome treated with testicular sperm extraction and intracytoplasmic sperm injection, future studies are needed with a higher number of cycles using frozen testicular sperm, in order to confirm or rebut that the freezing methodology affects negatively the clinical outcomes.
Wider implications of the findings: Data adds further information regarding testicular sperm retrieval rates and use of fresh or frozen testicular sperm in Klinefelter syndrome (KS) patients. High newborn rates were obtained only with fresh testicular sperm. Results also reassure KS patients about the safety relative to any abnormal chromosomal transmission to the born children.
Trial registration number
Not applicable
A history of undescended testes in young men with Klinefelter syndrome does not reduce the chances for successful microsurgical testicular sperm extraction
