Table 4 Unadjusted and adjusted odds ratios for risk factors among women giving birth preterm compared to women giving birth at term

Maternal stress during pregnancy

2.94

1.76–4.92

<0.000

2.15

1.18–3.92

0.012

Premature contractions

3.82

2.22–6.58

<0.000

2.73

1.48–5.03

0.001

Tobacco use

2.43

1.27–4.64

0.007

1.63

0.77–3.45

0.205

Previous preterm delivery

7.72

2.62–22.73

<0.000

6.15

1.95–19.44

0.002

Genital tract infection

3.74

1.89–7.38

<0.000

3.18

1.47–6.87

0.003