Ejaculatory abstinence less than 3 days results in a higher pregnancy rate (PR) following intrauterine insemination (IUI)

Abstract

Objective: The duration of ejaculatory abstinence is known to affect sperm concentration and motility, while morphology remains relatively constant. The effect of the abstinence interval on pregnancy outcome is not well characterized since most studies do not consider abstinence as an independent variable. In this study, we examined the influence of the abstinence interval on sperm parameters and pregnancy rates following IUI.Design: Retrospective analysis.Materials and Methods: 410 couples underwent 929 fresh, non-donor IUI cycles performed between June 1999 and October 2002. The influence of the duration of abstinence on the processed sperm parameters (concentration, motility, and total motile sperm [TMS]) and PR was analyzed by Pearson’s correlation. The impact of each of these parameters, including duration of abstinence, on PR was evaluated by stepwise logistic regression. ANOVA and independent t-tests were used to compare means.Results: Duration of abstinence correlated positively with sperm concentration and TMS, but negatively with motility. PR correlated negatively with duration of abstinence (r = −0.083, p < 0.05). Logistic regression revealed that only the duration of abstinence had a significant impact on PR. Table 1 shows the PR according to the abstinence interval. There were no differences in male or female age within or between the groups. An abstinence interval of ≤ 3 days had the highest mean PR (14%), while an interval of 4 to 10 days had a lower mean PR (10%), and an abstinence interval > 10 days had the lowest mean PR (3%) [Figure 1]. These abstinence interval groups were statistically different from each other (p < 0.05). Tabled 1∗ p < 0.05 compared to > 10 days.Figure 1Figure 1. Mean pregnancy rates of abstinence interval groups in IUI cycles.View Large Image Figure ViewerDownload (PPT)Conclusions: In the literature, the optimal duration of abstinence before performing a semen analysis or artificial insemination varies from 2 to 10 days. In clinical practice a 3 to 5 day interval is most commonly recommended. This study provides evidence that an abstinence interval ≤3 days improves the pregnancy rates following IUI, and that abstinence should be monitored as an independent factor in future studies evaluating sperm parameters and reproductive outcome. The correlation between duration of abstinence and pregnancy rate was not explained by sperm concentration, motility, or TMS and may be due to factors not accounted for by routine semen analysis. Objective: The duration of ejaculatory abstinence is known to affect sperm concentration and motility, while morphology remains relatively constant. The effect of the abstinence interval on pregnancy outcome is not well characterized since most studies do not consider abstinence as an independent variable. In this study, we examined the influence of the abstinence interval on sperm parameters and pregnancy rates following IUI. Design: Retrospective analysis. Materials and Methods: 410 couples underwent 929 fresh, non-donor IUI cycles performed between June 1999 and October 2002. The influence of the duration of abstinence on the processed sperm parameters (concentration, motility, and total motile sperm [TMS]) and PR was analyzed by Pearson’s correlation. The impact of each of these parameters, including duration of abstinence, on PR was evaluated by stepwise logistic regression. ANOVA and independent t-tests were used to compare means. Results: Duration of abstinence correlated positively with sperm concentration and TMS, but negatively with motility. PR correlated negatively with duration of abstinence (r = −0.083, p < 0.05). Logistic regression revealed that only the duration of abstinence had a significant impact on PR. Table 1 shows the PR according to the abstinence interval. There were no differences in male or female age within or between the groups. An abstinence interval of ≤ 3 days had the highest mean PR (14%), while an interval of 4 to 10 days had a lower mean PR (10%), and an abstinence interval > 10 days had the lowest mean PR (3%) [Figure 1]. These abstinence interval groups were statistically different from each other (p < 0.05). Tabled 1∗ p < 0.05 compared to > 10 days. ∗ p < 0.05 compared to > 10 days. Conclusions: In the literature, the optimal duration of abstinence before performing a semen analysis or artificial insemination varies from 2 to 10 days. In clinical practice a 3 to 5 day interval is most commonly recommended. This study provides evidence that an abstinence interval ≤3 days improves the pregnancy rates following IUI, and that abstinence should be monitored as an independent factor in future studies evaluating sperm parameters and reproductive outcome. The correlation between duration of abstinence and pregnancy rate was not explained by sperm concentration, motility, or TMS and may be due to factors not accounted for by routine semen analysis.