Transfer of a Poor-quality Along with a Good-quality Embryo on In vitro Fertilization/intracytoplasmic Sperm Injection-embryo Transfer Clinical Outcomes: a Systematic Review and Meta-analysis

Objective: To investigate the effect on the pregnancy rate of transfer of a good-quality embryo (GQE) and a poor-quality embryo (PQE) in comparison with a single GQE transfer.

Design: Systematic review and meta-analysis.

Setting: Not applicable.

Patient(s): Infertility patients undergoing in vitro fertilization/intracytoplasmic sperm injection- embryo transfer.

Intervention(s): Three major electronic databases (PubMed, Embase, and Cochrane Library) for studies those compared single GQE transfer to double embryo transfer of a GQE + PQE were searched. The Newcastle-Ottawa Quality Assessment Scale was used to evaluate the study quality. Random-effect meta-analysis was performed on all data for an overall analysis, followed by a subgroup analysis (fresh cleavage-stage embryos, fresh blastocysts, frozen-thawed blastocysts, and the same assessment criteria for blastocyst quality).

Main Outcome Measure(s): The primary outcome was clinical pregnancy rate (CPR).

Result(s): A total of 17 studies with 17,612 cycles for GQE transfer and 6,431 cycles for GQE + PQE transfer were included in the meta-analysis. No significant differences were found in CPR (relative risk [RR] = 1.02; 95% confidence interval [CI], 0.91-1.14) and live birth rate (RR = 0.96; 95% CI, 0.87-1.07) between GQE + PQE and GQE transfers. However, the transfer of GQE + PQE increased multiple pregnancy rate (RR = 0.14; 95% CI, 0.09-0.20) and multiple birth rate (RR = 0.08; 95% CI, 0.06-0.12), when compared with the patients undergoing a single GQE transfer. Subgroup analyses by type of embryo for transfer and assessment criteria for embryo quality showed similar trends.

Conclusion(s): Double embryo transfer with GQE + PQE does not result in increased or decreased CPR and live birth rate when compared with a single GQE transfer but leads to a higher multiple pregnancy rate and multiple birth rate.

Clinical Trial Registration Number: Prospero CRD42022296681 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=296681) registered on January 7, 2022.