Comparison of fresh testicular sperm aspiration and use of either thawed pre-frozen sperm or oocyte freezing: impact on cumulative live birth rates for couples experiencing ejaculation failure

Abstract

Study question: Is there a difference in the cumulative live birth rate (CLBR) after fresh testicular sperm aspiration (TESA) compared with the use of either pre-frozen sperm or oocyte freezing for couples experiencing ejaculation failure on the day of oocyte retrieval?

Summary answer: After adjusting for confounding factors, the use of pre-frozen sperm or the freezing and thawing of oocytes appeared to be as effective as TESA in achieving CLBRs for couples experiencing temporary ejaculation failure.

What is known already: Male patients may be concerned about experiencing temporary ejaculation failure on the day of their partner's oocyte retrieval, in which case they may choose surgical sperm retrieval, oocyte freezing on the day, or have their sperm frozen in advance. However, the clinical efficacy of these three options has not yet been evaluated.

Study design, size, duration: A retrospective data analysis was conducted on 65 178 oocyte retrieval cycles at a university-affiliated IVF center from January 2012 to May 2021.

Participants/materials, setting, methods: The overall characteristics, completed cycle characteristics, and clinical outcomes were analyzed among couples with ejaculation failure who underwent three distinct clinical interventions, with those receiving TESA serving as the control group. The primary outcome measure was the CLBR, and the secondary outcome measures were the clinical pregnancy rate (CPR) and live birth rate (LBR) per embryo transfer. A robust (modified) Poisson regression model was used to evaluate the association between the three clinical options for ejaculation failure and CLBRs.

Main results and role of chance: Of the eligible oocyte retrieval cycles, 756 cycles (1.2%) experienced ejaculation failure, with 640 cycles completing treatment. These treatments included 325 cycles using TESA, 227 cycles utilizing pre-frozen sperm, and 88 cycles involving frozen-thawed oocytes. The CLBRs for the TESA, thawed-sperm and thawed-oocyte groups were 36.9%, 48.9%, and 34.1%, respectively, showing a statistically significant difference (P = 0.007). Specifically, the thawed-sperm group demonstrated a significantly higher CLBR compared to the TESA group, while no significant difference was observed between the TESA and thawed-oocyte groups. Similarly, the CPRs and LBRs per embryo transfer for the three groups were 37.4%, 50.0%, and 41.8%, respectively (P = 0.005), and 29.9%, 39.6%, and 33.0%, respectively (P = 0.030). Again, the thawed-sperm group showed a significantly higher CPR and a significantly higher LBR, but no significant differences for the thawed-oocyte group, compared to the TESA group. Notably, the significant differences in both CLBR and LBR emerged after the second embryo transfer. However, after adjusting for multiple factors, including female age at oocyte retrieval, type and duration of infertility, female body mass index, number of previous IVF cycles, ovarian stimulation protocol, endometrial thickness on the last ultrasound, insemination method, number of oocytes retrieved, number of fertilized oocytes, and number of usable embryos on Day 3, the analysis revealed no significant association between CLBR and the use of pre-frozen sperm (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.81-1.44) or thawed oocytes (RR 1.01, 95% CI 0.76-1.33), compared with TESA.

Limitations, reasons for caution: Given that the study is retrospective and the sample size is too small, particularly concerning the use of thawed oocytes, we acknowledge that the data present here is only suggestive and refers to an association that warrants cautious interpretation. Therefore, further research in the form of prospective studies as well as randomized controlled trials is needed to provide a definitive answer to the research question.

Wider implications of the findings: Our findings suggest that using pre-frozen sperm or frozen-thawed oocytes can offer comparable CLBRs to TESA for cases of temporary ejaculation failure, providing clinical alternatives that may reduce the logistical challenges in ART cycles.

Study funding/competing interest(s): This study was supported by the National Nature Science Foundation of China (grant nos. 82101672, 82171589), the National Key Research and Development Program of China (grant nos. 2022YFC2702504, 2019YFE0109500), the Basic and Applied Basic Research Foundation of Guangdong Province (grant no. 2021A1515010774), and the Guangzhou Municipal Science and Technology Project (grant nos. 202102010075, 2023A4J0578). The authors declare that they have no conflict of interest in relation to the data in this paper.

Trial registration number: N/A.

Keywords: IVF; cumulative live birth; ejaculatory failure; frozen sperm; oocyte retrieval; oocyte vitrification; testicular sperm aspiration (TESA).

Figure 1.

Data selection flowchart. This study analyzed the outcomes after three clinical options, namely, testicular sperm aspiration (TESA), the use of pre-frozen sperm, and oocyte freezing with subsequent thawing, for eligible couples undergoing IVF but who experienced ejaculation failure on the day of oocyte retrieval. Data were from the 10-year period from 2012 to 2021.

Figure 2.

Kaplan–Meier curves of cumulative live birth rates for couples who experienced ejaculation failure on the day of oocyte retrieval. The curves show the cumulative live birth rates (CLBRs) for three clinical options as the number of embryo transfer cycles increased. Using the testicular sperm aspiration (TESA) group as the control group, after the second transfer, the use of pre-frozen sperm showed a significant increase in the CLBR (P < 0.05), while the thawed-oocyte group showed no significant difference (P > 0.05).

Figure 3.

Receiver operating characteristic (ROC) curve of the cumulative live birth prediction model for patients with ejaculation failure. The predicted probability values were generated by three variables, including female age at oocyte retrieval, the number of usable embryos on Day 3, and endometrial thickness on the last ultrasound, were used to reach an area under the curve of 0.793.