| |
Univariate
|
Multivariate 1
|
Multivariate 2
|
|---|
| |
HR
|
95 % CI
|
HR
|
95 % CI
|
HR
|
95 % CI
|
|---|
|
Term birth
|
Ref
| | |
Ref
| | |
Ref
| | |
|
Any preterm birth
|
2.99
|
2.34
|
3.83
|
2.50
|
1.92
|
3.24
|
2.27
|
1.74
|
2.94
|
|
Preterm birth by severity
| | | | | | | | | |
|
Late preterm birth
|
2.44
|
1.75
|
3.41
|
2.20
|
1.57
|
3.07
|
1.89
|
1.49
|
2.80
|
|
Moderately preterm birth
|
3.06
|
1.79
|
5.21
|
2.67
|
1.56
|
4.56
|
2.47
|
1.36
|
4.55
|
|
Extremely preterm birth
|
4.47
|
2.98
|
6.71
|
3.32
|
2.07
|
5.31
|
3.08
|
1.94
|
5.08
|
|
Preterm birth by onset
| | | | | | | | | |
|
Spontaneous preterm birth
|
2.42
|
1.76
|
3.31
|
2.26
|
1.64
|
3.10
|
2.03
|
1.48
|
2.80
|
|
Indicated preterm birth
|
4.29
|
3.02
|
6.10
|
2.99
|
2.03
|
4.39
|
2.74
|
1.87
|
4.03
|
|
Preterm birth by number
| | | | | | | | | |
|
1 preterm birth
|
2.81
|
2.17
|
3.65
|
2.40
|
1.83
|
3.15
|
2.20
|
1.67
|
2.88
|
|
≥2 preterm births
|
5.24
|
2.79
|
9.83
|
3.59
|
1.88
|
6.87
|
3.02
|
1.58
|
5.78
|
|
Smokinga
| | | | | | | | | |
|
Never smoking during pregnancy
|
Ref
| | | | | |
Ref
| | |
|
Smoking before last pregnancy
|
3.59
|
2.48
|
5.20
| | | |
2.50
|
1.70
|
3.68
|
|
Smoking during last pregnancy
|
2.97
|
2.44
|
3.61
| | | |
2.38
|
1.93
|
2.95
|
- Multivariate 1: Preterm birth adjusted for maternal age at delivery, country of birth, socioeconomic status, number of births, SGA, pregestational and gestational diabetes
- Multivariate 2: Variables in Multivariate 1 + maternal smoking during pregnancy
- a: Multivariate 2 adjusted for any preterm birth
