Effect of endometrial injury on pregnancy outcomes in infertile women undergoing intrauterine insemination

Objective: One of the most common treatments for infertility is intrauterine insemination. The objective of this study was to determine the effect of endometrial injury on pregnancy outcomes in unexplained infertile women undergoing intrauterine insemination.
Materials and Methods: In this randomized clinical trial, 122 women with unexplained infertility who referred to Shariati Hospital from 2018 to 2020 were enrolled. They underwent ovulation induction by letrozole and gonadotropins. On day 9 of stimulation, they randomly were assigned to two similar groups of same size. First group underwent endometrial local injury by pipelle endometrial sampling and second group (control group) received no intervention. Only 1 intrauterine insemination cycle was performed for each patient. Patients with negative pregnancy outcomes were followed up for 3 months. Endometrial thickness, dominant follicle count, chemical and clinical pregnancy rate, miscarriage rate and spontaneous pregnancy rate after intrauterine insemination cycle were compared between two groups.
Results: Endometrial thickness, dominant follicle count, chemical and clinical pregnancy rate and miscarriage rate in the same intrauterine insemination cycle were not different in two groups (P>0.05). However, spontaneous pregnancy rate after intrauterine insemination cycle was significantly higher in endometrial injury group (P=0.02).
Conclusion: According to the results and parameters of this study, endometrial injury increases pregnancy rates in later cycles but not the same intrauterine insemination cycle.