Table 2 Ovarian stimulation characteristics according to the two GnRH-a protocols before and after propensity score matching

FSH value on starting day (mIU/mL)

4.57 (1.98)

2.84 (1.97)

 < 0.001

4.54 (2.02)

2.81 (1.96)

 < 0.001

LH value on starting day (mIU/mL)

2.43 (1.38)

0.86 (0.52)

 < 0.001

2.43 (1.40)

0.88 (0.55)

 < 0.001

E₂ value on starting day (pg/ml)

31.82 (38.17)

21.23 (20.94)

 < 0.001

30.35 (35.26)

21.49 (18.51)

 < 0.001

P value on starting day (ng/ml)

0.53 (1.57)

0.42 (1.14)

0.017

0.51 (1.45)

0.49 (1.91)

0.785

FSH value on hCG day (mIU/mL)

16.49 (6.62)

17.00 (5.75)

0.016

16.52 (6.70)

17.57 (5.98)

 < 0.001

LH value on hCG day (mIU/mL)

2.96 (1.72)

1.07 (0.76)

 < 0.001

2.91 (1.68)

1.12 (0.71)

 < 0.001

E₂ value on hCG day (pg/ml)

3734.31 (1458.32)

2555.67 (1094.42)

 < 0.001

3737.01 (1489.16)

2536.74 (1094.60)

 < 0.001

P value on hCG day (ng/ml)

1.03 (0.45)

0.87 (0.44)

 < 0.001

1.03 (0.46)

0.88 (0.42)

 < 0.001

Endometrial thickness on hCG day(mm)

11.71 (2.69)

11.82 (2.73)

0.260

11.75 (2.69)

11.82 (2.74)

0.601

Dosage of Gn (IU)

2397.16 (908.41)

2433.40 (850.62)

0.226

2401.94 (911.91)

2416.23 (810.19)

0.716

Duration of Gn (days)

10.25 (1.34)

11.77 (1.72)

 < 0.001

10.28 (1.34)

11.76 (1.69)

 < 0.001

Moderate or severe OHSS rates, n (%)

4/1193 (0.34)

34/2851 (1.19)

 < 0.001

2/964 (0.21)

7/964 (0.73)

 < 0.001

No. of oocytes retrieved

9.38 (2.77)

9.67 (2.70)

0.002

9.29 (2.79)

9.41 (2.76)

0.345

No. of mature oocytes

8.64 (2.71)

8.97 (2.63)

 < 0.001

8.58 (2.71)

8.77 (2.69)

0.136

Fertilization rate (2PN) (%)

88.21 (12.05)

90.32 (10.92)

 < 0.001

87.97 (12.19)

90.20 (11.02)

 < 0.001

Cleavage rate (%)

98.09 (5.80)

98.62 (4.75)

0.003

98.06 (5.75)

98.85 (4.07)

 < 0.001

No. of embryos obtained

3.83 (1.37)

3.99 (1.37)

 < 0.001

3.84 (1.38)

3.98 (1.36)

0.026

good-quality embryo rate (%)

66.91 (29.17)

70.82 (27.13)

 < 0.001

67.79 (29.25)

72.17 (26.56)

 < 0.001

Blastocyst formation rate (%)

56.57(42.88)

65.42(41.28)

 < 0.001

56.19 (42.66)

65.37 (41.22)

 < 0.001

No. of transferred embryos, n (%)

0.298

0.568

 1

397/1193 (33.28)

901/2851 (31.60)

338/964 (35.06)

350/964 (36.31)

 2

796/1193 (66.72)

1950/2851 (68.40)

626/964 (64.94)

614/964 (63.69)

Embryo transfer day, n (%)

 < 0.001

0.274

 Day 3

652/1193 (54.65)

1385/2851 (48.58)

520/964 (53.94)

496/964 (51.45)

 Day 5

541/1193 (45.35)

1466/2851 (51.42)

444/964 (46.06)

468/964 (48.55)