Fresh or frozen testicular sperm? Guidance from an etiology-classified retrospective study on ICSI cycles for patients with azoospermia

Using testicular sperm, men with azoospermia can father children. Sperm cryopreservation helps avoid the risk of cycle canceling because of the failure of testicular sperm retrieval. However, cryopreservation of testicular sperm can potentially impair sperm function. In addition, the different qualities of testicular sperm retrieved from men with various etiologies of azoospermia can lead to different intracytoplasmic sperm injection (ICSI) outcomes after sperm cryopreservation. A retrospective analysis was performed to elucidate the influence of frozen testicular sperm from men with different etiologies of azoospermia on assisted reproductive technology (ART) treatment outcomes. Testicular sperm retrieval rates were also compared. The fertilization rate was found to be influenced by testicular sperm cryopreservation in most cases, especially for patients with azoospermia factor c (AZFc) deletion, and embryo development was significantly impeded when frozen testicular sperm from Klinefelter syndrome (KS) patients were used. Moreover, ART treatment outcomes after embryo transfer were not significantly influenced by testicular sperm cryopreservation for any of the etiologies. In addition, significantly higher sperm retrieval rates were achieved in cryptorchidism, KS, and AZFc deletion patients, whereas the testicular sperm retrieval rate was significantly lower in patients with idiopathic nonobstructive azoospermia. Collectively, our findings suggest that except for patients with KS, testicular sperm retrieval prior to initiating ovarian stimulation of the patient’s partner should be considered the first-line approach. In addition, assisted oocyte activation should be performed in ICSI cycles using frozen testicular sperm, especially for patients with AZFc deletion.