Embryological, clinical, and newborn outcomes from 583 treatment cycles with fresh and frozen testicular spermatozoa.

Background: Besides non-obstructive azoospermia, other conditions also benefit from the use of testicular sperm extraction, but their clinical outcomes remain to be explored in detail.

Objective: To compare the use of fresh and frozen testicular spermatozoa in patients submitted to testicular sperm extraction because of idiopathic or secondary non-obstructive azoospermia, and after recurrent failed intracytoplasmic sperm injection attempts using ejaculated or aspirated testicular spermatozoa.

Materials and methods: We retrospectively evaluated 325 patients with normal karyotypes and absence of Y-chromosome microdeletions that used testicular sperm extraction for fertility treatments. Comparisons included detailed embryological, clinical, and newborn outcomes.

Results: Patients underwent 503 treatment cycles, 269 with fresh and 234 with frozen testicular spermatozoa. No significant differences were observed between fresh and frozen spermatozoa regarding clinical pregnancy (38.0%/43.2%), live birth delivery (32.2%/34.0%), and newborn (40.1%/43.2%) rates, the same being observed in cumulative clinical pregnancy (47.9%/48.5%), live birth delivery (41.7%/38.3%), and newborn (50.4%/48.5%) rates. Also, no significant differences were observed between fresh and frozen spermatozoa per pathology (idiopathic or secondary non-obstructive azoospermia, cryptorchidism, abnormal semen parameters, cryptozoospermia, obstructive azoospermia, and anejaculation). However, in idiopathic non-obstructive azoospermia, frozen embryo transfer cycles from fresh sperm cycles evidenced significantly higher rates of live birth delivery and newborn. As cycles with frozen spermatozoa evidenced significantly higher female age, time of infertility, and basal follicle stimulating hormone, and significantly lower number of follicles, female characteristics were thereafter individualized. The presence of mixed factors did not affect outcomes. Good ovarian response cases exhibited significantly higher rates of implantation and newborn, whereas younger women cases showed significantly higher rates of implantation, clinical pregnancy, and newborn; however, when fresh spermatozoa were compared to frozen spermatozoa, these differences were no longer present.

Discussion and conclusion: Data provide detailed embryological, clinical, and newborn outcomes associated with specific conditions in which testicular sperm extraction was required. It also highlights no detrimental effects on outcomes when frozen testicular spermatozoa is used.