Effect of Ejaculatory Abstinence Duration on Laboratory and Clinical Outcomes in IVF: A Retrospective Analysis

BACKGROUND: The recommended ejaculatory abstinence (EA) period prior to semen collection varies between regulatory bodies. The World Health Organization recommends 2-7 days, whereas the European Society of Human Reproduction and Embryology and the Nordic Association for Andrology recommend 3-4 days. Prolonged epididymal storage of spermatozoa may increase sperm DNA fragmentation, and impair subsequent embryo development and implantation outcomes. Consequently, further evidence is needed to clarify the optimal abstinence duration. OBJECTIVES: To evaluate the impact of EA on laboratory and clinical outcomes in subfertile couples undergoing in-vitro fertilization (IVF). MATERIALS AND METHODS: This single-center retrospective cohort study included 2899 couples undergoing 3873 IVF cycles from 2013 to 2022. Laboratory outcomes included semen parameters, blastulation rate, and top-quality blastulation rate. Clinical outcomes included pregnancy rate, miscarriage rate, and live birth rate. Associations between EA duration and both blastulation outcomes and clinical outcomes were evaluated using multivariable analysis, adjusting for all available confounders. RESULTS: Several semen parameters differed significantly between EA periods (p < 0.05), with higher total sperm count, sperm concentration, total motile count, and semen volume observed at longer durations of EA. However, neither blastulation rate nor top-quality blastulation rate were significantly impacted by EA duration (p > 0.05). Increasing EA duration was associated with reduced pregnancy rates, reporting an adjusted odds ratio (aOR) of 0.786 (95% CI 0.685-0.903) (p < 0.001). Miscarriage rate was not significantly associated with EA duration (p > 0.001). Although live birth rate fell with increasing EA duration, this association did not reach statistical significance, aOR 0.886 (95% CI 0.769-1.020) (p = 0.0921). DISCUSSION AND CONCLUSION: While blastulation rates appear unaffected by EA duration, shorter EA periods may be associated with higher pregnancy rates in couples undergoing IVF. However, no significant associations were observed for miscarriage or live birth rates. Large multicenter studies are needed to better define the impact of EA duration on IVF outcomes.