Table 2.

The concentration of beta-hCG in day 5 spent culture medium in different subgroups^a

Subgroup		No. of samples	beta-hCG (mIU/ml)	P value
Blastocyst cavity grade of inner cell mass	Cavity-expanded	46	1.66 [1.41, 1.90]	0.007
	Cavity-unexpanded	52	1.29 [1.16,1.42]
	A OR B	31	1.63 [1.27,1.99]	NSb
	C OR < C	67	1.39 [1.27,1.50]
	A OR B	33	1.72 [1.39,2.06]	0.007
	C OR < C	65	1.34 [1.22,1.45]

^a1 negative sample was not counted in Table 2; the data were expressed as mean and 95%CI grade of trophoblast

^bNS, not significant