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

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.Systematic review and meta-analysis.Not applicable.Infertility patients undergoing in vitro fertilization/intracytoplasmic sperm injection- embryo transfer.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).The primary outcome was clinical pregnancy rate (CPR).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.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.Prospero CRD42022296681 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=296681) registered on January 7, 2022.