Factors influencing clinical pregnancy failure in patients with RIF treated with the IVF-ET technique: a cohort analysis based on a propensity score approach

Objective: To investigate the risk factors for clinical pregnancy in patients with recurrent embryo implantation failure (RIF) treated with in vitro fertilization-embryo transfer (IVF-ET) technique. Methods 1074 patients treated with IVF-ET were matched for propensity score to reduce the effect of confounding factors. The final endometrial receptivity analysis (ERA) group and the conventional frozen embryo transfer (FET) group were each matched to 204 cases, with 201 in the failed pregnancy group and 207 in the successful pregnancy group. Their basic demographic characteristics and relevant clinical data were collected, and the Kaplan-Meier method was used to estimate the survival curves of the patients' pregnancy rates, and the factors influencing them were analysed using Cox regression models. Results The success and failure rates of clinical pregnancies in patients with RIF were 50.74% and 49.26%, respectively. Patients in the failed pregnancy group did not receive an ERA, had > 3 previous implantation failures, and were transferred with a single embryo, with no quality embryos transferred. Conclusion Not receiving an ERA, having > 3 previous implantation failures, using single embryo transfer and not transferring quality embryos are risk factors for clinical pregnancy in patients with RIF.