Table 1 Baseline characteristics of participants by quartiles of SII

Age

28.32 ± 3.18

28.54 ± 3.23

28.20 ± 3.33

28.18 ± 2.92

0.581

Primary infertility

164 (67.8%)

173 (71.8%)

183 (75.9%)

176 (72.7%)

0.254

78 (32.2%)

68 (28.2%)

58 (24.1%)

66 (27.3%)

Duration of infertility(y)

3.12 ± 2.00

3.37 ± 1.96

3.21 ± 2.04

3.45 ± 2.19

0.281

Smoking history, n (%)

 No

240 (99.2%)

240 (99.6%)

240 (99.6%)

240 (99.2%)

1.000

 Yes

2 (0.8%)

1 (0.4%)

1 (0.4%)

2 (0.8%)

Gravidity

0.00 (0.00 to 1.00)

0.00 (0.00 to 1.00)

0.00 (0.00 to 1.00)

0.00 (0.00 to 1.00)

0.363

Parity

0.00 (0.00 to 0.00)

0.00 (0.00 to 0.00)

0.00 (0.00 to 0.00)

0.00 (0.00 to 0.00)

0.662

Number of abortions

0.00 (0.00 to 1.00)

0.00 (0.00 to 0.00)

0.00 (0.00 to 0.00)

0.00 (0.00 to 0.00)

0.661

Basal FSH(IU/L)

6.84 ± 1.58

6.74 ± 3.03

6.60 ± 1.39

6.37 ± 1.65

0.060

Basal E2(pg/mL)

55.11 ± 10.20

44.41 ± 20.33

50.26 ± 37.80

46.47 ± 20.89

0.182

Basal LH(IU/L)

7.72 ± 4.01

7.11 ± 4.02

7.71 ± 4.02

7.98 ± 4.69

0.139

Basla T(ng/dl)

0.56 (0.43 to 0.70)

0.55 (0.43 to 0.72)

0.56 (0.42 to 0.70)

0.57 (0.42 to 0.75)

0.997

AMH (ng/ml)

11.16 ± 5.28

11.48 ± 5.48

11.52 ± 5.32

12.27 ± 5.67

0.155

AFC

14.23 ± 4.27

15.07 ± 4.79

16.16 ± 5.28

16.46 ± 5.17

 < .001

BMI (Kg/m²)

0.680

  < 18.5

11 (4.55%)

8 (3.32%)

8 (3.32%)

11 (4.55%)

 18.5–25

144 (59.50%)

128 (53.11%)

143 (59.34%)

132 (54.55%)

 25–30

65 (26.86%)

77 (31.95%)

71 (29.46%)

69 (28.51%)

  ≥ 30

22 (9.09%)

28 (11.62%)

19 (7.88%)

30 (12.40%)

Starting dose of Gn (IU)

188.21 ± 33.11

192.71 ± 39.46

188.68 ± 35.15

188.42 ± 36.61

0.466

Total Gn dose (IU)

1834.29 ± 590.33

1887.87 ± 659.64

1852.45 ± 712.67

1795.18 ± 625.93

0.464

Duration of Gn (day)

9.29 ± 1.72

9.24 ± 1.72

9.28 ± 2.01

9.18 ± 1.48

0.910

Starting dose of GnRH-ant (IU)

0.25 (0.12 to 0.25)

0.25 (0.12 to 0.25)

0.25 (0.12 to 0.25)

0.25 (0.12 to 0.25)

0.258

Total GnRH-ant dose^a(IU)

1.12 (0.75 to 1.50)

1.00 (0.75 to 1.50)

1.25 (0.88 to 1.50)

1.25 (0.88 to 1.50)

0.155

Duration of GnRH-ant (day)

5.19 ± 2.16

4.82 ± 1.75

5.10 ± 1.87

5.17 ± 1.82

0.121

Triggered with hCG

217(89.67%)

209(86.72%)

206(85.48%)

197(81.40%)

0.072

Triggered with GnRH-a + HCG

25(10.33%)

32(13.28%)

35(14.52%)

45(18.59%)

E2 on HCG start day (pg/ml)

5769.50 (4257.00 to 8217.00)

5612.00 (4395.00 to 8325.00)

6142.00 (4555.00 to 9117.00)

6871.00 (4805.37 to 9928.00)

0.019

P on HCG start day(ng/ml)

1.25 (0.91 to 1.69)

1.29 (0.94 to 1.70)

1.31 (0.92 to 1.84)

1.42 (1.05 to 2.00)

0.017

LH on HCG start day (IU/L)

2.69 (1.67 to 3.97)

2.65 (1.66 to 3.96)

2.67 (1.75 to 4.77)

2.59 (1.64 to 4.64)

0.907

P on HCG start day(ng/ml)

1.25 (0.91 to 1.69)

1.29 (0.94 to 1.70)

1.31 (0.92 to 1.84)

1.42 (1.05 to 2.00)

0.017

LH on HCG start day (IU/L)

2.69 (1.67 to 3.97)

2.65 (1.66 to 3.96)

2.67 (1.75 to 4.77)

2.59 (1.64 to 4.64)

0.907