Does total motile sperm count predict embryo quality and ICSI success in young normal-weight women? A retrospective multicentre study.

RESEARCH QUESTION: Can the fresh and post-selection total motile sperm count (TMSC) predict intracytoplasmic sperm injection (ICSI) outcomes?

DESIGN

This multicentre retrospective cohort study involved couples with infertility (>12 months) undergoing ICSI. Participants were divided into five groups by baseline TMSC: group I, less than 1 million; group II, 1 to less than 5 million; group III, 5 to less than 10 million; group IV, 10-20 million; and group V, over 20 million. The primary outcome was the cumulative live birth rate, with secondary outcomes of oocyte fertilization rate, embryo number/quality, biochemical and clinical pregnancy rates and miscarriage rate.

RESULTS

In total 5813 couples met the inclusion criteria. After adjustment for confounding factors, the TMSC of fresh samples was positively correlated with the oocyte fertilization rate, with higher values observed in all groups compared with group I (P < 0.001). Moreover, TMSC appears to influence the cumulative live birth rate for oocytes used (hazard ratio [HR] 1.25, 95% CI 1.05-1.48, adjusted P = 0.0116), while no difference was observed when the number of embryos transferred and transfers were considered. Finally, no difference was found in embryo quality or other reproductive outcomes. For post-selection TMSC, none of the groups had a higher fertilization rate than group I after adjusting for confounding factors.

CONCLUSIONS

This study suggests that changes in TMSC alone can predict the oocyte fertilization rate and slightly influence the cumulative live birth rate, particularly when considering the total number of inseminated oocytes. These underscore the critical role of sperm quality in the success of ICSI. However, other female and/or male parameters may also contribute to the outcomes.