Table 2 Comparison between IVF cycles with double trigger (GnRH-a + hCG) versus hCG trigger

Length of stimulation (day)

9.76 ± 1.21

9.32 ± 1.45

-1.737

Dosage of gonadotropin (IU)

2601.84 ± 903.12

2770.74 ± 885.15

1.045

Peak estradiol levels on day of hCG administration (pmol/l)

8632.34 ± 5126.10

9214.84 ± 6502.59

0.447

Fertilization method

 Routine IVF (%)

42.86 (15)

22.86 (8)

 ICSI (%)

57.14 (20)

77.14 (27)

Number of oocytes retrieved

9.66 ± 6.09

9.11 ± 6.30

-0.654

Number of MII oocytes (ICSI cycle)

4.43 ± 2.74

6.21 ± 3.93

1.516

Number of 2PN zygotes

2.71 ± 2.59

3.57 ± 3.39

1.432

Number of cleavage embryos

3.63 ± 3.81

4.40 ± 3.52

1.103

Number of 2PN cleavage embryos

2.11 ± 2.15

3.54 ± 3.37

2.35

Number of top-quality embryos

0.89 ± 0.99

2.23 ± 2.05

3.687

Proportion of MII per number of oocytes retrieved (%) (ICSI cycle)

59.27 ± 30.56

66.27 ± 27.97

0.985

Proportion of 2PN zygote per number of oocytes retrieved (%)

33.21 ± 27.56

44.22 ± 33.18

1.885

Proportion of cleavage embryo per number of oocytes retrieved (%)

39.80 ± 29.60

53.87 ± 31.38

2.11

Proportion of 2PN cleavage embryo per number of oocytes retrieved (%)

27.22 ± 27.13

43.89 ± 33.01

2.583

Proportion of top-quality embryo per number of oocytes retrieved (%)

14.19 ± 19.76

27.05 ± 26.26

2.463

Cumulative hCG positive rate per stimulation cycle (%)

8.57 (3/35)

20.00 (7/35)

Cumulative clinical pregnancy rate per stimulation cycle (%)

2.86 (1/35)

20.00 (7/35)

Cumulative persistent pregnancy rate per stimulation cycle (%)

0 (0/35)

14.29 (5/35)

Cumulative live birth rate per stimulation cycle (%)

0 (0/35)

14.29 (5/35)