Table 1.

Subject’s characteristics of FET^* cycles in groups A^** and B^***

Variable	Group A** (n = 166)	Group B*** (n = 195)	P-value †
Female age (mean±SD)	30.89±4.73	30.48±4.78	0.975
Cause of infertility N (%)
Female factor	71 (42.8)	88 (45.1)	0.619
Male factor	74 (44.6)	76 (39)
Unknown	7 (4.2)	8 (4.1)
Both	14 (8.4)	23 (11.8)
No. of transferred embryo (mean±SD)	1.96±0.3	1.96±0.2	0.8
Embryo quality N (%)
Grade A****	22 (13.3)	39 (20)	0.232
Grade B*****	122 (73.5)	133 (68.2)
Grade C******	22 (13.3)	23 (11.8)

^*FET

^**ET in the day of warming

^***ET in the one day after warming

^****With regular size blastomere, and no fragmentation

^*****The embryos with uneven blastomeres and/or less than 10% fragmentation

^******The embryos with more than 10% fragmentation but no more than 25% of blastomeres

^†The data were assessed using Chi-squared test and student’s t-test