A longer time interval between operative hysteroscopy and intrauterine insemination is negatively associated with pregnancy outcomes.

Intrauterine pathology can create an unfavourable environment for pregnancy. We therefore sought to determine optimal time interval between operative hysteroscopy and intrauterine insemination (IUI) to optimise pregnancy outcomes. This study was a retrospective cohort study of IUI cycles following an operative hysteroscopy performed at our institution between January 2018 and August 2023. Our primary outcome was clinical pregnancy following IUI. Patients were grouped into one of four cohorts based on the number of days between operative hysteroscopy and subsequent IUI. We compared cohorts by estimating risk ratios using modified Poisson regression models, adjusting for female age, subfertility diagnosis, and number of prior IUI cycles and utilised P values. We identified 896 patients undergoing a total of 917 IUI cycles following an operative hysteroscopy in whom clinical pregnancy occurred in 16.4% of all IUI cycles. After adjustment, a longer interval between operative hysteroscopy and IUI was associated with a lower probability of a clinical pregnancy. In a subgroup analysis of 728 hysteroscopic polypectomies, the clinical pregnancy rate following IUI was similar to that for all operative hysteroscopies (16.3% v 16.4%, respectively). In conclusion, delaying IUI after hysteroscopy is not needed to improve pregnancy outcomes.