Cleavage (Day 3) Vs Blastocyst (D5 and D6) Frozen Embryo Transfer

Abstract

Objectives Knowledge about the success of the IVF program in frozen embryo transfer using cleavage stage (day 3) versus blastocyst stage (day 5 and day 6) is still limited. Several studies have found that embryo transfer at the blastocyst stage is more effective than at the cleavage stage. This study aimed to determine the quality of embryos after freezing-thawing and success rates on frozen embryo transfer on day 3 compared to day 5 and day 6. Materials and Methods: This retrospective case control analytic study included 157 participants aged below 40 years old who met our inclusion criteria between March 2018 to December 2022. Twenty-nine patients had day 3 frozen embryo transfers with a total of 65 frozen-thawed embryos, 110 patients had day 5 frozen embryo transfers with a total of 203 frozen-thawed blastocysts, and 18 patients had day 6 frozen embryo transfers with a total of 30 frozen-thawed blastocysts. Parameters were observed based on survival rate of embryos after freezing-thawing, number of embryo transfer per groups, pregnancy, implantation, miscarriages, intrauterine fetal death (IUFD), anembryonic pregnancy, and live birth rates. Results: There was no significant difference in survival rate of embryos after freezing-thawing among groups, however, pregnancy and implantation rates were significantly higher for day 5 frozen embryo transfer compared to those on day 3 and day 6 frozen embryo transfers. No significant differences were found in the miscarriage rate, IUFD, and live birth rate in the three groups. Keywords: day 3 frozen embryo transfer, day 5 and day 6 frozen embryo transfer, recovery embryos, pregnancy rate, implantation rate, live birth rate