Impact of Day-3 embryo cell number on pregnancy, obstetric and perinatal outcomes in frozen-thawed single blastocyst transfer cycles

1

The study evaluated the impact of Day-3 embryo cell number on pregnancy outcomes after frozen-thawed single blastocyst transfer.
2

A total of 6437 frozen-thawed single blastocyst transfer cycles were analyzed from 2016 to 2024 at a large reproductive center.
3

Embryos with ≤5 or 6 cells on Day-3 were associated with significantly lower odds of live birth compared to the 8-cell group.
4

No significant differences in obstetric and perinatal outcomes were observed among singleton live births from ≤5 or 6-cell groups.
5

The findings may inform blastocyst selection and patient counselling during IVF treatment.

Frontiers In Endocrinology

by Feng Xiong, Caiyun Wan, Xiaoqi Peng, Qing Sun, Shiru Xu, Lianghui Diao, Peilin Chen, Huixian Zhong, Meilan Mo, Tao Zhang
June 22, 2026

1