Sn (%)

Sp (%)

PPV (%)

NPV (%)

LR+

LR-

Bishop ≥ 7

70.41

79.11

67.65

81.17

3.74

0.36

Cervical obliteration ≥ 50%

85.71

16.46

38.89

65.00

1.02

0.87

Cervical dilatation ≥ 2 cm

59.18

74.68

59.18

74.68

2.34

0.55

Ultrasound cervical length < 25 mm

87.76

33.54

45.03

81.54

1.32

0.36

Sacculation

69.39

82.91

71.58

81.37

4.06

0.34