Impact of two different embryo loading techniques on pregnancy outcome in in vitro fertilization and frozen-thawed embryo transfer cycles

Abstract

Objective To evaluate the impact of two different embryo loading techniques on pregancy rates and implantation rate in in vitro fertilization and embryo transfer (IVF-ET) cycles and frozen-thawed embryo transfer (FET) cycles. Methods We retrospectively analyzed 543 fresh ET cycles and 658 FET cycles. The patients were placed in group A and group B, group A: the volume of medium containing embryos>air bubble surrounding it; group B: the volume of medium containing embryos<air bubble surrounding it. The pregnancy outcome was compared between the two groups. Results In fresh ET cycles, the pregnancy rate in group B (64.52%) was significantly higher than that in group A (54.62%) (P 0.05). The implantation rate was higher in group B (39.51%) than in group A (26.81%), the difference was significant (P<0.05). There were no significant differences in both pregnancy rate and implantation rate of blastocyst, but it was higher in group B than in group A. Conclusion The volume of medium containing embryos < air bubble surrounding it can significantly improve the pregnancy rate and implantation rate in fresh ET cycles and FET cycles. Key words: Embryo loading techniques; In vitro fertilization-embryo transfer (IVF-ET); Frozen-thawed embryo transfer (FET); Pregnancy rate; Implantation rate