Table 2 Adjusted odds ratios from multivariable logistic regression analysis, stratified by parity

Height (cm)

0.98

0.97, 0.99

0.99

0.98, 1.00

BMI (kg/m²)

1.02

0.98, 1.04

0.99

0.97, 1.00

Age (years)

1.03

1.01, 1.05

1.01

1.00, 1.03

 Africa or Eastern Mediterranean

2.07

1.53, 2.82

1.55

1.22, 1.98

 Other

1.31

1.00, 1.70

1.83

1.51, 2.22

 1

4.23

3.43, 5.22

2.03

1.71, 2.40

 2

20.57

15.32, 27.63

3.38

2.67, 4.29

 3 or more

34.57

21.60, 55.31

6.67

4.93, 9.02

Multi-fetal gestation

8.44

5.20, 13.68

1.19

0.73, 1.95

History of any cervical procedures

2.48

1.80, 3.42

1.82

1.38, 2.38

Parity more than two

~

~

1.23

1.04, 1.44

Smoking during pregnancy

~

~

1 .40

1.15, 1.71

Previous PPROM

~

~

1.53

1.04, 2.26

Previous preterm delivery

~

~

2.06

1.63, 2.61

Weeks to term of birth prior to index

~

~

1.47

1.41, 1.54

 1

~

~

0.93

0.76, 1.13

 2 or more

~

~

0.65

0.30, 1.43

 1

~

~

0.75

0.62, 0.92

 2 or more

~

~

0.63

0.41, 0.96

Previous macrosomia

~

~

0.86

0.72, 1.02