Table 2.

Day 5 and day 6 morulas and their ability for blastocyst development in the following 1 day of in vitro cultivation after freezing-thawing procedure

	Day 5 morulas (n = 329)				Day 6 morulas (n = 18)
	M1	M2	M3	P	M1	M2	M3	P
Morula No.	54	131	144		0	7	11
BFRa, %	48/54, 88.9%	97/131, 74.0%	76/144, 52.8%	<0.001		3/7, 42.9%	3/11, 63.6%	NS
Topb BFR, %	35/54, 64.8%	33/131, 25.2%	13/144, 9.0%	<0.001		0/7 0%	1/11 9.1%	NS

^aBFR Blastocyst formation rate. ^b Top, >3AA blastocysts. NS Not significant