Optimal number of high-quality cleavage-stage embryos for extended culture to blastocyst-stage for transfer in women 38 years and older

Abstract

Purpose We aimed to evaluate the pregnancy outcomes of cleavage-stage embryo transfers (ETs) for the first time and explore optimal number of high-quality cleavage-stage embryos for extended culture to blastocyst-stage in women of advanced maternal age (AMA).Methods We retrospectively identified 1646 AMA women ≥ age 38 years for the first fresh ETs between January 2014 and December 2020 at our hospital. Double ETs were divided into three groups as follows: DET-HH (two high-quality embryos), DET-HL (one high-quality and one low-quality embryo), and DET-LL (two low-quality embryos) groups. We mainly analyzed the pregnancy outcomes of double cleavage-stage ETs with different embryo grades and blastocyst-stage ETs with different number of high-quality cleavage-stage embryos on day 3.Results Our data indicated that the DET-HH group had significantly higher clinical pregnancy, ongoing pregnancy, and live birth rates than DET-HL and DET-LL groups (p .05).Conclusions Extended culture to blastocyst-stage for transfer was safe and recommended for AMA women with ≥ 4 high-quality embryos on day 3.

Keywords

• AMA
• embryo transfer
• pregnancy outcomes
• high-quality embryos