Skip to main content

Table 4 Univariable analysis of risk factors for low birth weight, 2010 São Luís birth cohort

From: Low birth weight in São Luís, northeastern Brazil: trends and associated factors

Variables

%Low birth weight

Odds ratio*

95% Confidence interval

p**

Newborn’s sex

   

0.026

 Male

6.7

1

Reference

 

 Female

8.3

1.26

(1.02; 1.56)

 

Preterm birth

   

<0.001

 Yes

40.3

20.92

(16.53; 26.48)

 

 No

3.1

1

Reference

 

IUGR***

   

<0.001

 No

3.3

1

Reference

 

 Mild

8.0

2.56

(1.97; 4.05)

 

 Moderate

15.2

5.27

(3.79; 8.13)

 

 Severe

72.2

76.87

(55.40; 106.64)

 

Maternal age(years)

   

0.107

 <18

9.4

1.38

(0.98; 1.95)

 

 18 – 19

8.7

1.28

(0.91; 1.78)

 

 20 – 34

6.9

1

Referência

 

 ≥35

9.1

1.33

(0.92; 1.93)

 

Maternal schooling (years)

   

0.861

 0 to 4

7.0

0.96

(0.54; 1.72)

 

 5 to 8

7.2

0.99

(0.66; 1.41)

 

 9 to 11

7.7

1.06

(0.78; 1.44)

 

 ≥12

7.3

1

Reference

 

 Missing

15.4

2.32

(0.50; 10.74)

 

Marital status

   

0.020

 Married

6.3

1

Reference

 

 Consensual union

7.3

1.18

(0.89; 1.56)

 

 Without a companion

9.5

1.56

(1.13; 2.17)

 

Family income (minimum wages)

   

0.107

 ≤1

8.3

1.37

(0.97; 1.93)

 

 1- 3

7.9

1.31

(0.99; 1.72)

 

 >3

6.2

1

Reference

 

 Missing

7.8

1.29

(0.93; 1.80)

 

Maternal smoking during pregnancy

   

<0.001

 No

7.2

1

Reference

 

 Yes

16.1

2.49

(1.65; 3.73)

 

Occupation of the family head

   

0.346

 Non-manual

6.9

1

Reference

 

 Skilled manual worker

8.2

1.20

(0.90; 1.60)

 

 Unskilled manual worker

6.9

0.98

(0.73; 1.33)

 

 Missing

8.5

1.24

(0.68; 2.25)

 

Parity

   

0.003

 1

8.8

1.50

(1.16; 1.93)

 

 2

6.0

1

Reference

 

 ≥3

6.8

1.14

(0.83; 1.56)

 

Adequacy of prenatal care use

   

<0.001

 Adequate

7.6

1

Reference

 

 Inadequate

6.8

0.89

(0.70; 1.12)

 

 No care

20.0

3.04

(1.80; 5.11)

 

 Missing

6.2

0.80

(0.47; 1.36)

 

Category of delivery care

   

0.293

 Private

6.6

1

Reference

 

 Public

7.7

1.17

(0.86; 1.58)

 

Type of delivery

   

0.265

 Vaginal

7.9

1

Reference

 

 Cesarean

7.1

0.88

(0.71; 1.09)

 
  1. *Odds Ratio (OR) calculated by simple logistic regression.
  2. **p-value calculated by the log likelihood ratio test.
  3. ***IUGR–intrauterine growth restriction based on the birth weight ratio.