Table 1 Baseline characteristics of patients among groups A–E stratified by age

Cycles (n)

1425

844

206

183

120

144

269

107

39

25

female age(year)

29.17 ± 2.89

29.32 ± 2.92

29.45 ± 2.93

29.50 ± 2.69

29.38 ± 3.62

0.419

36.65 ± 1.91

37.17 ± 2.01

37.16 ± 1.93

37.51 ± 2.53

37.08 ± 2.57

0.063

BMI (kg/m2)

21.46 ± 3.09

21.70 ± 3.20

21.34 ± 3.13

21.71 ± 3.48

21.67 ± 3.41

0.343

21.96 ± 2.75

22.59 ± 2.82

22.59 ± 2.88

22.38 ± 2.45

22.06 ± 2.41

0.210

Basal FSH (mIU/ml)

5.08 ± 1.24

4.92 ± 1.25

5.07 ± 1.37

4.96 ± 1.21

5.16 ± 1.44

0.104

5.15 ± 1.63

5.15 ± 1.31

4.81 ± 1.22

5.15 ± 1.66

5.11 ± 0.91

0.701

AMH (ng/ml)

8.06 ± 5.71

7.80 ± 4.03

7.22 ± 3.68

6.85 ± 3.72

6.98 ± 3.80

0.095

6.08 ± 3.56

6.34 ± 3.75

5.08 ± 2.25

5.74 ± 3.86

5.80 ± 3.07

0.347

Duration of infertility (years)

3.44 ± 1.94

3.57 ± 2.06

3.85 ± 2.08

3.53 ± 1.94

3.33 ± 1.89

0.052

4.21 ± 3.39

5.08 ± 3.92

5.06 ± 3.96

5.81 ± 4.17

4.72 ± 3.02

0.099

Type of infertility

0.276

0.522

 Primary infertility

56.14

(800/1425)

52.25

(441/844)

56.31

(116/206)

55.19

(101/183)

60.83

(73/120)

27.08

(39/144)

33.09

(89/269)

25.23

(27/107)

33.33

(13/39)

28.0

(7/25)

 Secondary infertility

43.86

(625/1425)

47.75

(403/844)

43.69

(90/206)

44.81

(82/183)

39.17

(47/120)

72.92

(105/144)

66.91

(180/269)

74.77

(80/107)

66.67

(26/39)

72.0

(18/25)

Endometrial preparation (%)

0.669

0.149

 HRT

84.0

(1197/1425)

86.26

(728/844)

85.44

(176/206)

84.70

(155/183)

83.33

(100/120)

70.83

(102/144)

76.95

(207/269)

82.24

(88/107)

79.49

(31/39)

64.0

(16/25)

 Natural

16.0

(228/1425)

13.74

(116/844)

14.56

(30/206)

15.30

(28/183)

16.67

(20/120)

29.17

(42/144)

23.05

(62/269)

17.76

(19/107)

20.51

(8/39)

36.0

(9/25)

 Endometrial thickness (mm)

9.04 ± 1.61

8.67 ± 1.58

8.85 ± 1.53

8.93 ± 1.60

8.99 ± 1.56

0.106

8.98 ± 1.83

8.89 ± 1.61

8.96 ± 1.63

8.86 ± 1.73

9.13 ± 1.52

0.939