Purpose: The pregnancy outcome and the chances of birth were assessed according to embryo quality after IVF or ICSI.
Methods: The implantation rate (IR), the loss of gestational sacs rate (LGSR), and birth rate (BR) were determined according to the cleavage stage and the integrity of blastomeres after day-2 homogeneous embryo transfers (n = 1812).
Results: The LGSR was higher after transfers of 2-3-cell or 5-6-cell embryos and was significantly increased when more than 20% of the embryo volume was fragmented in 4-cell embryos. After transfers of 4-cell embryos without fragmentation, the BR was significantly higher than the BR after transfers of 4-cell embryos with 1-20% fragmentation (16.6% vs 13.1%). The difference was the consequence of a higher IR (20.4% vs 17.3%) but also of a lower LGSR (18.9% vs 24.2%).
Conclusions: Not only implantation and the ability to give a pregnancy, but also the capacity to give a live birth are dependent on the embryo quality.