Table 2 Comparisons of FET cycles undergoing SBT between AC/BC and CA/CB groups stratified by blastocyst development speed

Cycles (n)

407

69

580

150

female age (year)

31.87 ± 4.01

31.39 ± 4.23

0.503

32.92 ± 4.30

32.91 ± 4.24

0.877

BMI (kg/m2)

22.01 ± 3.38

22.02 ± 3.17

0.875

21.81 ± 2.97

21.91 ± 3.46

0.242

AMH (ng/ml)

6.13 ± 4.21

5.75 ± 3.94

0.582

4.78 ± 3.63

4.98 ± 3.93

0.887

Duration of infertility (years)

4.75 ± 3.24

4.95 ± 3.26

0.692

4.87 ± 3.21

4.84 ± 3.22

0.721

Endometrial preparation (%)

0.838

0.597

Natural

37.84

(154/407)

62.16

(27/69)

38.97

(226/580)

61.03

(62/150)

HRT

39.13

(253/407)

60.87

(42/69)

41.33

(354/580)

58.67

(88/150)

Endometrial thickness (mm)

8.92 ± 1.35

9.27 ± 1.59

0.064

8.98 ± 1.46

8.87 ± 1.37

0.062

Pregnancy rate

43.73

(178/407)

34.78

(24/69)

0.164

21.21^#

(123/580)

19.33*

(29/150)

0.614

Multiple pregnancy rate

3.93

(7/178)

4.17

(1/24)

0.999

2.44

(3/123)

3.45

(1/29)

0.575

Early miscarriage rate

22.47

(40/178)

20.83

(5/24)

0.856

27.64

(34/123)

27.59

(8/29)

0.995

Miscarriage rate

23.03

(41/178)

20.83

(5/24)

0.809

30.08

(37/123)

34.48

(10/29)

0.645

Ectopic pregnancy rate

1.12

(2/178)

0

(0/24)

0.999

0

(0/123)

0

(0/29)

/

Live birth rate

33.17

(135/407)

27.54

(19/69)

0.355

14.66^#

(85/580)

12.67*

(19/150)

0.535

Singleton

32.19

(131/407)

26.09

(18/69)

0.312

14.66

(85/580)

12.67

(19/150)

0.535

Twin

0.98

(4/407)

1.45

(1/69)

0.545

0

(0/580)

0

(0/150)

/

Preterm birth (<37weeks)

8.89

(12/135)

15.79

(3/19)

0.592

8.14

(7/86)

0

(0/19)

0.436

Singleton

8.15

(11/135)

10.53

(2/19)

0.999

8.14

(7/86)

0

(0/19)

0.436

Twin

0.74

(1/135)

5.26

(1/19)

0.232

0

(0/86)

0

(0/19)

/