Impact of Trigger-to-Insemination Interval on Intrauterine Insemination Outcomes: A Retrospective Cohort Study

Objective: To assess the Intrauterine Insemination (IUI) outcome based on different time intervals between ovulation trigger and IUI. Methods: This study presents a retrospective review of 209 patients who received IUI at an Assisted Reproductive Technology (ART) Clinic affiliated with Chettinad Super Speciality Hospital between 2013 and 2024. Couples with unexplained infertility, male partner aged 23-40 years and female partner aged 21-35 years with bilateral patent fallopian tubes were included in the study. The exclusion criteria were abnormal semen parameters, incomplete & frozen samples, double IUI and donor samples. The study cohort was divided into three subgroups based on the time interval between hCG trigger administration and IUI [Group I: Concurrent IUI with hCG trigger (n = 13), Group II: IUI performed at 24 hours following hCG trigger (n = 25), Group III: IUI performed at 36 hours following hCG trigger (n = 171)]. Statistical analysis was performed using IBM SPSS software, with categorical data evaluated by Chi-square test. Results: Based on the different time interval groups, the clinical pregnancy rate was 7.69 % in Group I, 8% in Group II and 15.2% in Group III. There is no statistical significance between the different time interval of IUI and hCG trigger on IUI outcome (p=0.499). Conclusion: According to our study, we could not find any correlation between the time interval of IUI and hCG trigger on IUI outcome.