Department of Reproductive Andrology & Sichuan Human Sperm Bank, West China Second University Hospital, Sichuan University, Chengdu, China.
Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China.
Andrology. 2024 Sep;12(6):1224-1235. doi: 10.1111/andr.13583. Epub 2024 Jan 10.
Infertility affects 186 million people worldwide, with male factors contributing to 50% of infertility cases. Semen analysis is a key for diagnosing male factor infertility, but sperm parameters can be influenced by ejaculatory abstinence (EA) duration. Shortening or prolonging EA can impact on semen quality and assisted reproductive technology (ART) outcomes, but the optimal EA duration remains unclear, particularly for infertility patients.
This study conducts a comprehensive meta-analysis to explore the impact of varying abstinence durations on semen quality and fertility outcomes.
Three English database (PubMed, Embase, and Cochrane Central Register of Controlled Trials) as well as four Chinese database (China National Knowledge Infrastructure, Chinese Scientific Journals database, WanFang database, and Chinese Biomedical Literature database) were searched from 2000 to August 2023. The classical meta-analysis and "one-stage" dose-response meta-analysis were conducted to compare the associations of different abstinence durations (short-term abstinence vs. long-term abstinence) on semen quality in healthy adult and different type of infertile patients.
There were 85 eligible studies were finally included. The meta-analysis of volume (mean difference [MD] = -0.95 mL, 95% confidence interval [CI]: -1.16 to -0.74 mL), total sperm count (TSC) (MD = -102.45×10, 95% CI: -117.98×10 to -86.91×10), sperm concentration (SC) (MD = -11.88×10/mL, 95% CI: -18.96×10/mL to -4.80×10/mL), DNA fragmentation index (DFI) (MD = -2.37%, 95% CI: -4.73% to -0.01%) in healthy men showed a significant decrease with different abstinence durations (short-term abstinence vs. long-term abstinence). The meta-analysis of infertile men showed significant decrease in volume in various subgroups (MD range: -0.73 to -1.17 mL) with P < 0.01; TSC (MD = -61.93×10, 95% CI: -88.84×10 to -35.01×10), SC (MD = -5.39×10/mL, 95% CI: -9.97×10 to -0.81×10/mL), DFI (MD = -5.63%, 95% CI: -10.19% to -1.06%) in unexplained infertility subgroup; significant increase in viability (MD = 6.14%, 95% CI: 3.61% to 8.68%) in the unexplained infertility subgroup. The dose-response meta-analysis showed that TSC in oligozoospermia showed a nonlinear increase (coefficient from 3.38 to -5.76, P from 0.02 to 0.22) and the truncation point was around the 4th to 5th abstinence day. The percentage of progressive motile sperm (PR) in asthenozoospermia showed a significant decrease (coefficient = -2.39, 95% CI: -4.28 to -0.50). For fertility outcomes of different ARTs, only the clinical pregnancy rate (CPR) in the intrauterine insemination (IUI) subgroup showed a significant decrease around the 3rd day (coefficient = 0.85, 95% CI: 0.75 to 0.97).
Short-term abstinence may be associated with limited improvements in semen quality in healthy men but could be more beneficial for infertile men, especially within the first 4 days of abstinence. Caution is urged in making definitive conclusions about the causal relationship between abstinence time and semen quality changes due to potential confounding and interactions.
全球有 1.86 亿人受到不孕不育的影响，其中 50%的不孕不育病例与男性因素有关。精液分析是诊断男性因素不育症的关键，但精子参数可能会受到射精禁欲（EA）持续时间的影响。缩短或延长 EA 可能会影响精液质量和辅助生殖技术（ART）的结果，但最佳 EA 持续时间仍不清楚，特别是对于不孕不育患者。
本研究进行了一项全面的荟萃分析，以探讨不同禁欲持续时间对精液质量和生育结果的影响。
从 2000 年至 2023 年 8 月，我们检索了三个英文数据库（PubMed、Embase 和 Cochrane 中央对照试验注册库）和四个中文数据库（中国国家知识基础设施、中国科学期刊数据库、万方数据库和中国生物医学文献数据库），对健康成年男性和不同类型不孕不育患者的不同禁欲持续时间（短期禁欲与长期禁欲）与精液质量的关联进行了经典荟萃分析和“一阶段”剂量反应荟萃分析。
最终有 85 项符合条件的研究被纳入。对体积（平均差异 [MD] = -0.95 mL，95%置信区间 [CI]：-1.16 至 -0.74 mL）、总精子计数（TSC）（MD = -102.45×10，95%CI：-117.98×10 至 -86.91×10）、精子浓度（SC）（MD = -11.88×10/mL，95%CI：-18.96×10/mL 至 -4.80×10/mL）和 DNA 碎片指数（DFI）（MD = -2.37%，95%CI：-4.73% 至 -0.01%）的荟萃分析显示，在健康男性中，不同禁欲持续时间（短期禁欲与长期禁欲）与精液质量显著下降相关。对不孕不育男性的荟萃分析显示，在各种亚组中，体积明显下降（MD 范围：-0.73 至 -1.17 mL），差异有统计学意义（P < 0.01）；TSC（MD = -61.93×10，95%CI：-88.84×10 至 -35.01×10）、SC（MD = -5.39×10/mL，95%CI：-9.97×10 至 -0.81×10/mL）和 DFI（MD = -5.63%，95%CI：-10.19% 至 -1.06%）在不明原因不孕亚组中；在不明原因不孕亚组中，活力明显增加（MD = 6.14%，95%CI：3.61% 至 8.68%）。剂量反应荟萃分析显示，少精子症的 TSC 呈非线性增加（系数为 3.38 至 -5.76，P 从 0.02 到 0.22），截断点约在第 4 至 5 天。弱精子症中 PR 的百分比呈显著下降（系数为-2.39，95%CI：-4.28 至 -0.50）。对于不同的 ART 生育结果，只有宫内授精（IUI）亚组的临床妊娠率（CPR）在第 3 天左右显著下降（系数=0.85，95%CI：0.75 至 0.97）。
短期禁欲可能与健康男性精液质量的有限改善有关，但对不孕不育男性可能更有益，尤其是在禁欲的前 4 天内。由于潜在的混杂和相互作用，对于禁欲时间与精液质量变化之间的因果关系，谨慎做出明确的结论是很重要的。
