Table 3.

Cohen’s Kappa coefficients from the evaluation by five embryologists of the three features of blastocysts (grade of expansion, inner cell mass and trophectoderm)

Morphological feature	Class 2	Class 3	Class 4	Average
Blastocyst expansion
Kappa	0.422 (0.381-0.464)	0.222 (0.181-0.264)	0.508 (0.466-0.549)	0.371(0.342-0.400)
P value	<0.001	<0.001	<0.001	<0.001
Inner cell mass	Grade A	Grade B	Grade C	Average
Kappa	0.404(0.363-0.446)	0.178 (0.137-0.220)	0.285 (0.243-0.326)	0.267 (0.236-0.298)
P value	<0.001	<0.001	<0.001	<0.001
Trophectoderm	Grade A	Grade B	Grade C	Average
Kappa	0.353 (0.312-0.395)	0.209 (0.167-0.250)	0.376(0.334-0.417)	0.299(0.268-0.331)
P value	<0.001	<0.001	<0.001	<0.001

Kappa values are expressed with confidence intervals (CI) 95% between brackets. Class 2; Early blastocyst, Class 3; Full blastocyst, and Class 4; Expanded blastocyst.