P-020 Clinical outcomes of 583 treatment cycles with fresh and cryopreserved testicular sperm in cases without karyotype abnormalities and Y chromosome microdeletions needing testicular sperm extraction
Authors: Pereira M , Cunha M , Silva J , Viana P , Barros N , Teixeira da Silva J , Oliveira C , Ferraz L , Barros A , Sousa M 
Published: July 2024

Abstract

Study question
What are the embryological, clinical and newborn outcomes using fresh and cryopreserved testicular sperm in non-obstructive azoospermia patients? Are the differences between both techniques significant?

Summary answer
In this population there was a high live birth delivery rate with no significant differences observed in the outcomes using fresh and cryopreserved testicular sperm.

What is known already
The use of cryopreserved testicular sperm has been considered of lower quality due to freezing/thawing consequences (1). Nevertheless, cryopreserved testicular sperm presents the advantages of avoiding female stimulation in cases of failed testicular sperm retrieval, or multiple testicular biopsies (2). However, the majority of the studies evidenced no significant differences in the clinical outcomes between the use of cryopreserved and fresh sperm (3). As only a few studies are dedicated to compare both techniques (4) we expanded the number of cycles and provided full demographic, stimulation, embryological, clinical and newborn outcomes.
References:
1- (https://doi.org/10.1016/j.cryobiol.2017.06.008)
2- (https://doi.org/10.1016/S1472-6483(10)60839-5)
3- (https://doi.org/10.1080/2090598X.2021.1932303)
4- (https://doi.org/10.1016/j.fertnstert.2008.04.051)

Study design, size, duration
We retrospectively evaluated, during 20 consecutive years (2003-2023), 325 patients without karyotype abnormalities and Y-chromosome microdeletions, needing testicular sperm extraction. This study compares 583 ART treatment cycles, 503 with testicular sperm and 80 cycles with frozen embryo transfer, From the 503 cycles, 269 used fresh testicular sperm (247 patients) and 234 used cryopreserved testicular sperm (64 patients). Of the 80 cycles with frozen embryo transfer, 52 used fresh testicular sperm and 28 cryopreserved testicular sperm.

Participants/materials, setting, methods
Patients were screened for karyotype abnormalities (1) and Y-chromosome microdeletions (2,3). Conventional semen analysis was performed according to the World Health Organization (4) guidelines. An open testicular biopsy method was performed for TESE according to established protocols (5) When surplus spermatozoa was found, the fluid was cryopreserved. Treatments with fresh or cryopreserved testicular sperm were performed with ICSI. Surplus embryos were cryopreserved and later transferred.
References:
1-ISBN-10: 0471962996
2-(https://doi.org/10.4103/1008-682X.172827)
3- (https://doi.org/10.2147/TACG.S267421)
4- (https://doi.org/10.3390/life11121368)
5- (https://doi.org/10.5935/1518-0557.20210081)

Main results and the role of chance
The mean ages were 34.6±4.3 (20-44) in female and 37.4±5.6 (27-64) in male patients. Infertility causes of the 325 patients, included 20 (6.2%) cases of azoospermia due to oncology and immunosuppression treatments, 109 (33.5%) cases of azoospermia due to primary or other secondary causes (surgery, torsion, orchitis, congenital), 40 (12.3%) cases of cryptorchidism, and 156 (48%) cases needing TESE due to failure of previous treatments (anejaculation, obstructive azoospermia, cryptozoospermia). The rate of successful sperm retrieval (SSR) was 96%. Comparing fresh with cryopreserved testicular sperm, the following rates of fertilization (97% vs 93.9%), blastocyst development (44.9% vs 36.7%), implantation (26.5% vs 29.8%), clinical pregnancy (38% vs 43.2%), live birth delivery (32.2% vs 34.0%) and newborn (40.1% vs 43.2%) were obtained. There were 3 newborns with congenital malformations (2 major and 1 minor). Mean gestation ages were 38.3±2.1 weeks in cycles with fresh sperm and 37.8±2.1 weeks with cryopreserved sperm. The newborns mean weight was 2861.0±623.6 g in cycles with fresh sperm and 2793.7±591.7 g with cryopreserved sperm. After frozen embryo transfer (FET), the following cumulative rates were obtained, clinical pregnancy (48.7% vs. 48.5%), live birth delivery (37.5% vs 38.3%) and newborn (45.7% vs. 48.5%). No significant differences were found between groups

Limitations, reasons for caution
Our studied population included 20.3% couples suffering from mixed infertility factors which could lead to additional difficulty to achieve a successful clinical pregnancy with live birth delivery and newborn. To better study a technique used to male infertility, it would be interesting to study a population with male factor only.

Wider implications of the findings
The present study can give more security to the use of cryopreserved techniques since no significant differences were found between the use of fresh testicular sperm and cryopreserved testicular sperm in this population. It also suggests that TESE is a procedure with good rates of embryological, clinical and newborn outcomes.

Trial registration number
NA