Clinical outcomes after elective double-embryo transfer in frozen cycles for women of advanced maternal age A retrospective cohort study

We aimed to determine the clinical outcome of double cleavage-stage embryo transfers in frozen-thawed embryo transfer cycles for older women. This study analyzed a total of 8189 cleavage-stage frozen-thawed embryo transfer cycles between January 2013 and December 2017 at Sir Run Run Shaw Hospital. All cycles were sorted into 3 groups based on patient age: <= 35 years (Group A), 36 to 37 years (Group B), and >= 38 years (Group C). The clinical pregnancy rate (CPR), implantation rate (IR), live birth rate (LBR), miscarriage rate, multiple pregnancy rate (MPR), preterm birth rate, and low-birth-weight rate were compared between the 3 groups. Significant differences in CPR, IR, LBR, MPR, and premature birth rate were found among the 3 groups. The CPR, IR, LBR, and MPR in Group A were higher than those in Group C. Transfers of 2 high-quality embryos resulted in significant differences in CPR, IR, LBR, MPR, and neonatal weight among the 3 groups, but no differences in premature birth and abortion rates were observed. Transfers with 1 high-quality and 1 fair-quality embryo resulted in significant differences in CPR, IR, and LBR among the 3 groups. Comparison of transfers of 2 high-quality embryos with 1 high-quality and 1 fair-quality embryo showed that the CPR and LBR were significantly lower for the latter in Groups A and C, but Group B had no salient changes. Higher IR and LBR and lower MPR may be achieved by selection of optimal embryo types for patients of different ages. Two high-quality embryos need to be transferred in women older than 38 years. For women aged 36 to 37 years, 1 high-quality embryo or 1 high-quality plus 1 fair-quality embryo should be singled out for transfer. For women younger than 35 years, a single high-quality embryo should be selected for transfer.

Automated summary

This study aimed to investigate the clinical outcome of double cleavage-stage embryo transfers in frozen-thawed embryo transfer cycles for older women. The results showed that selecting optimal embryo types can achieve higher pregnancy rates, implantation rates, and live birth rates, while reducing the multiple pregnancy rate. Women older than 38 years need to transfer two high-quality embryos, while women aged 36 to 37 years should select one high-quality embryo or one high-quality plus one fair-quality embryo for transfer. Women younger than 35 years should choose a single high-quality embryo for transfer.