The interval between insemination and ovulation predicts outcome after intrauterine insemination with donor sperm (IUI-D)

Objective: To identify whether the time interval from insemination to ovulation (I-O interval) affects outcome after intrauterine insemination with donor sperm (IUI-D). Methods: A retrospective study was conducted in a public assisted reproductive medicine center between January, 2014 and December, 2016 in Xi'an, China. The data were collected from the medical records and generalized estimating equations (GEEs) were used to evaluate the effects of various variables on IUI outcome. Results: A total of 2091 IUI-D cycles from 1165 couples were included in this study. Multiple predictors were identified for (live birth rate) LBR. The I-O interval was the predictor for LBR. An I-O interval ≥19 h significantly decreased CPR (odds ratio [OR], 95% confidence interval [CI]: 0.29, 0.17–0.48) and LBR (OR, 95% CI: 0.32, 0.19–0.55). The presence of at least two follicles ≥18 mm on ovulation day significantly increased the LBR (OR, 95%CI: 1.27, 1.01–1.60). Women aged 35 years and older had a significantly decreased LBR (OR, 95% CI: 0.61, 0.38–0.98). Conclusion: The I-O interval, a new prognostic factor, in combination with the woman's age and number of mature follicles, can predict the outcome after IUI-D. IUI-D is best performed within 19 h of I-O interval for a higher probability of clinical pregnancy and live birth.