Table 4 Characteristics of cycles with positive and negative clinical pregnancy

Age, year

35.8 ± 3.2

35.9 ± 3.6

NS

Endometrial preparation, hormone replacement, %

74.4

82.4

NS

Peak endometrium thickness, cm

1.1 ± 0.3

1.1 ± 0.2

NS

Containing embryos from top morula (M1), n (%)

16 (37.2)

26 (30.6)

NS

No. of embryos transferred per cycle, n

1.8 ± 0.6

1.7 ± 0.5

NS

No. of blastocysts^a contained in transferred embryos

1.7 ± 0.7

1.4 ± 0.6

0.023

No. of top blastocysts^a contained in transferred embryos

0.9 ± 0.7

0.4 ± 0.6

<0.001