The effect of sequential embryo transfer on pregnancy outcomes in patients with recurrent implantation failure: a systematic review and meta-analysis of randomized controlled trials

The aim of our study was to assess the impact of sequential embryo transfer on pregnancy outcomes among patients with recurrent implantation failure (RIF).

We conducted a comprehensive search across various databases for eligible clinical trials from inception to January 2024. Randomized controlled trials (RCTs) were included if they compared sequential embryo transfer, comprising both cleavage-stage and blastocyst-stage embryos, with other transfer protocols in infertile women with repeated implantation failure. Meta-analysis was performed using Revman software. Our primary focus was on the ongoing pregnancy rate. Our secondary measures included rates of chemical pregnancies, clinical pregnancies, miscarriages, and multiple pregnancies.

Seven RCTs, encompassing 909 patients, met the inclusion criteria. Sequential embryo transfer demonstrated a significant increase in the ongoing pregnancy rate compared to the control group (OR = 2.28, 95% CI [1.46, 3.56], p = 0.003). Moreover, the sequential embryo transfer group exhibited notable improvements in chemical and clinical pregnancy rates. There were no statistically significant differences between the groups regarding multiple pregnancy and miscarriage rates (p > 0.05).

Sequential embryo transfer shows promise in enhancing pregnancy outcomes among RIF patients. However, additional trials are warranted to validate our findings.