Impact of Shorter Abstinence Periods on Semen Parameters: A Systematic Review and Meta-Analysis.

Purpose: The success of assisted reproductive technology (ART) relies heavily on semen parameters, and it is influenced by the length of the abstinence period. The World Health Organization (WHO) recommends a 2- to 7-day abstinence period. Even so, efficacy is still suboptimal. Thus, this study aims to determine whether shorter abstinence periods (<2 days) can improve semen parameters.

Materials and methods: This study is a systematic review and meta-analysis. A literature search was performed across five databases: PubMed, Embase, ProQuest, Scopus, and Wiley Online Library using the PICO format. Retrieved articles were assessed according to eligibility criteria and the PRISMA flow diagram. Those eligible for quantitative analysis were assessed using forest plots. Risks of bias were tested using the Newcastle-Ottawa Scale.

Results: A total of 22 studies and 31,640 samples were included. Studies showed that short abstinence periods significantly reduced semen volume (mean difference [MD] -0.83, p<0.01), sperm concentration (MD -8.39, p<0.01), and DNA fragmentation (MD -3.82, p<0.01). No differences in sperm morphology were identified. Meanwhile, the overall effect for total (MD 2.30, p<0.05) and progressive motile sperm (MD 2.18, p<0.01) was significantly increased. Subgroup analysis on oligospermia patients revealed a significant increase in normal sperm morphology (MD 1.64, p<0.01) along with reduced DNA fragmentation (MD -3.30, p<0.05). However, no significant changes were seen among other sperm parameters.

Conclusions: In conclusion, our findings suggest a shorter abstinence period could be beneficial due to its effect on sperm motility and DNA fragmentation. Additionally, oligospermia patients will benefit from improved sperm morphology. These findings can provide insight for future guidelines to promote a shorter abstinence period for improving ART outcomes.