Embryo morphology score on day 3 is predictive of implantation and live birth rates

Purpose: To determine if embryo cleavage state or morphology on day 3 correlates with implantation or live birth rates. A retrospective cohort study of all fresh embryo transfers over 2 years.Methods: Patients were grouped by the average cleavage state and morphology. Cleavage state groups were: <6, ≥6, <8, and ≥8 cells. Morphology groups by average grade were: group 1 (best) = 1, group 2 = >1≤2, group 3 = >2≤3, and group 4 (worst) = >3≤4.Results: The overall implantation rate for 158 cycles was 28.1% with a live birth rate of 37.3%. Morphologic state was highly predictive of both implantation rate and live birth rate. Implantation rates by group were 54.8% (group 1), 30.4% (group 2), 23.8% (group 3), and 11.1% (group 4). Likewise, live birth rates among groups were 61.5, 39, 20, and 21%, respectively. Cleavage state was not predictive of outcome.Conclusions: Embryo grade is highly predictive of implantation and live birth rate and can be used to determine the number of embryos to transfer. Cleavage state is not predictive of outcome.