Ideal Stage of Embryo Transfer to Improve Outcomes for Women of Advanced Maternal Age

Abstract Background The purpose of this retrospective study was to optimise the transplantation strategy for women of advanced maternal age to achieve live births within the shortest time. Methods Data were collected from patients older than 40 years who underwent assisted reproductive therapy at our centre from 1 January 2009 to 31 December 2019. A total of 1233 cases of fresh cleavage embryo transfer cycles, 280 cases of frozen-thawed blastocyst transfer cycles, and 26 cases of frozen-thawed cleavage embryo transfer cycles were included. Multivariable logistic regression was performed to adjust for confounding factors. Results The main outcome was the live birth rate. The secondary outcomes were the clinical pregnancy rate, spontaneous abortion rate, and neonatal outcomes. We found that the blastocyst formation rate of patients older than 40 years was 23.5%, the freezing cycle rate was 19.8%, and the fresh embryo transfer rate was 83.0%. Conclusions Cleavage embryo transfer should be performed first to reduce the cycle cancellation rate. If the number of retrieved oocytes is more than eight, then blastocyst transplantation can be considered after fully discussing the advantages and disadvantages of blastocyst culture with patients. Alternatively, cleavage embryo transfer can be performed first, and frozen-thawed blastocyst transfer can be performed next if cleavage embryo transfer is unsuccessful.