Table 4

Adjusted odds ratios for LBW infants by socioeconomic level among women of Mexico City

Variable

Model 1

Model 2

Model 3

OR

95% CI

OR

95% CI

OR

95% CI

Socioeconomic level

Medium

1.14

[0.75,1.74]

1.16

[0.76,1.77]

1.12

[0.72,1.74]

Low

2.57

[1.19,5.58]

2.45

[1.13,5.36]

2.68

[1.19,6.03]

Maternal age (years)

<19

0.74

[0.43,1.25]

0.74

[0.43,1.26]

0.57

[0.32,1.03]

>30

1.17

[0.70,1.98]

1.09

[0.64,1.84]

1.34

[0.76,2.38]

Maternal education (years)

< 7

1.21

[0.58,2.56]

1.11

[0.52,2.40]

1.05

[0.47,2.34]

7–9

1.29

[0.63,2.62]

1.23

[0.59,2.55]

1.39

[0.66,2.94]

10–12

1.56

[0.78,3.13]

1.61

[0.79,3.27]

1.82

[0.87,3.77]

Unmarried

0.99

[0.49,2.01]

1.08

[0.52,2.28]

0.96

[0.44,2.08]

No accessibility to public services

0.68

[0.34,1.33]

0.58

[0.29,1.17]

0.56

[0.27,1.14]

Smoking before pregnancy

0.99

[0.57,1.72]

1.07

[0.60,1.90]

Smoking during pregnancy

1.09

[0.43,2.78]

1.14

[0.43,2.99]

Hypertension

1.61

[0.95,2.73]

1.55

[0.90,2.68]

Urinary tract infection

1.23

[0.83,1.83]

1.14

[0.76,1.71]

No calcium supplementation

1.98

[1.01,3.87]

2.30

[1.14,4.63]

No iron supplementation

1.23

[0.84,1.80]

1.32

[0.89,1.96]

No prenatal care

1.15

[0.47,2.87]

1.27

[0.52,3.19]

Primiparous

1.73

[1.05,2.83]

Pre-gestational weight(kgs)

<48

2.33

[1.33,4.08]

49–54

1.28

[0.71,2.31]

>60

1.32

[0.74,2.36]

Previous preterm birth^a

2.95

[1.04,8.38]**

Previous low birth weight^a

2.61

[1.36,5.04]

Previous abortion^a

0.52

[0.17,1.63]

^aonly applicable for women with more than one pregnancy.

Torres-Arreola et al. BMC Public Health 2005 5:20   doi:10.1186/1471-2458-5-20