The effect of intrauterine insemination preceding frozen-thawed elective single embryo transfer in couples with unexplained subfertility

Introduction: This prospective randomized controlled trial aimed to evaluate the effect of intrauterine insemination (IUI) before frozen-thawed elective single embryo transfer (FT-eSET). Material and methods: A total of 200 couples with unexplained subfertility underwent in-vitro fertilization (IVF) treatment. Patients were randomly assigned to either FT-eSET or IUI preceding FT-eSET. Both groups were composed of 100 women. IUI was timed 6 days before FT-eSET in the IUI preceding FT-eSET group. Implantation rates (IR), biochemical and clinical abortion rates (AR), clinical pregnancy rates (PR), ongoing pregnancy rates (PRs), and live birth rates were measured in this study. Results: The IUI preceding FT-eSET group was associated with higher rates of clinical pregnancy, 54% vs. 42%, but not significantly. Similarly, IR, PR and live birth rate were higher in the IUI preceding FT-eSET group but not significantly. In the IUI preceding FT-eSET group, the biochemical and clinical abortion rates were lower than in the control group (9.5% vs. 14.2% and 5.5% vs. 5.2%, respectively). However, no statistically significant difference was found between the two groups, either. Conclusions: This is the first study showing that IUI may precede FT-eSET to improve PR in couples with unexplained subfertility. Also, performing IUI before FT-eSET may decrease biochemical and clinical abortion rates. © 2020 Termedia & Banach.