Sociodemographic variables
|
Maternal age (years)
|
< 20
|
1.76
|
1.57–1.98
|
1.48
|
1.32–1.67
|
35 and over
|
0.45
|
0.39–0.52
|
1.09
|
0.97–1.24
|
20 to 34
|
1
|
-
|
1
|
-
|
Schooling level
|
≤ 7 years
|
1.21
|
1.05–1.39
|
3.37
|
2.94–3.88
|
8 to 11 years
|
1.32
|
1.16–1.50
|
2.29
|
2.01–2.62
|
12 or more years
|
1
| |
1
| |
Skin color
|
White
|
1
|
-
|
1
|
-
|
Black
|
1.19
|
1.00–1.42
|
1.75
|
1.49–2.06
|
Brown
|
1.26
|
1.15–1.40
|
1.49
|
1.35–1.65
|
Yellow
|
1.66
|
1.14–2.42
|
1.67
|
1.18–2.32
|
Individual variables
|
Marital status
|
With partner
|
1
|
-
|
1
|
-
|
Without partner
|
2.42
|
2.04–2.87
|
4.17
|
3.59–4.85
|
Has paid work
|
Yes
|
1
|
-
|
1
|
-
|
No
|
1.39
|
1.26–1.53
|
1.60
|
1.46–1.75
|
Alcohol use
|
No
|
1
|
-
|
1
|
-
|
Yes, but with no alcoholism risk
|
1.04
|
0.83–1.31
|
1.22
|
0.98–1.52
|
Yes, with alcoholism risk
|
1.40
|
1.17–1.67
|
1.87
|
1.64–2.14
|
Tobacco use
|
No
|
1
|
-
|
1
|
-
|
Yes
|
1.01
|
0.86–1.18
|
2.26
|
1.98–2.57
|
Parity
|
Primiparous
|
1
|
-
|
1
|
-
|
1
|
0.97
|
0.87–1.09
|
1.59
|
1.41–1.80
|
2
|
1.02
|
0.88–1.16
|
3.92
|
3.34–4.60
|
3 or more
|
1.16
|
0.96–1.40
|
7.51
|
6.35–8.88
|
Adverse obstetric outcomes in previous pregnancyb
|
Neonatal death
|
No
|
1
| |
1
| |
Yes
|
0.61
|
0.46–0.81
|
0.61
|
0.48–0.76
|
Stillbirth
|
No
|
1
| |
1
| |
Yes
|
0.86
|
0.63–1.16
|
0.90
|
0.69–1.17
|
Preterm birth (GA < 37 weeks)
|
No
|
1
| |
1
| |
Yes
|
1.05
|
0.80–1.29
|
1.44
|
1.23–1.69
|
Low birth weight (BW < 2500 g)
|
No
|
1
| |
1
| |
Yes
|
0.95
|
0.80–1.14
|
1.37
|
1.18–1.59
|
Maternal complicationsb
|
No
|
1
| |
1
| |
Yes
|
0.95
|
0.81–1.12
|
1.22
|
1.04–1.42
|