Table 1 Characteristics of pregnant women and risk of measuring small-for-gestational age, Madang, PNG, 2009–2012

Maternal age

 16-21

35.9

(241/671)

Referent

 22-26

36.2

(243/671)

0.85

(0.69, 1.03)

 ≥27

27.9

(187/671)

0.86

(0.69, 1.07)

0.196

Gravidity

 >1

47.9

(320/671)

Referent

 1

52.1

(351/671)

1.35

(1.13, 1.61)

0.001

Ethnicity

 Madang/Morobe

63.5

(426/671)

Referent

 Other

36.5

(245/671)

0.84

(0.70, 1.02)

0.075

Infant sex

 Male

46.3

(307/663)

Referent

 Female

53.7

(356/663)

1.03

(0.86, 1.22)

0.767

Smoking

 No

82.9

(556/671)

Referent

 Yes

17.1

(115/671)

0.98

(0.79, 1.22)

0.886

Betel nut consumption

 No

20.0

(134/669)

Referent

 Yes

80.0

(535/669)

0.88

(0.72, 1.09)

0.238

Literate

 No

8.8

(59/670)

Referent

 Yes

91.2

(611/670)

1.10

(0.81, 1.49)

0.546

Mother generating income

 No

45.5

(298/655)

Referent

 Yes

54.5

(357/655)

1.04

(0.87, 1.24)

0.689

Partner generating income

 No

32.5

(217/667)

Referent

 Yes

67.5

(450/667)

0.87

(0.73, 1.02)

0.086

Area of residence

 Urban

18.5

(124/670)

Referent

 Peri-urban

23.7

(159/670)

1.15

(0.87, 1.52)

 Rural

57.8

(387/670)

1.06

(0.83, 1.37)

0.602

Raised CRP at enrolment (≥5 mg/L)

 No

80.0

(392/490)

Referent

 Yes

20.0

(98/490)

0.89

(0.69, 1.15)

0.367

Gestational week at fetal weight measurement^b

 22-25

26.3

(395/1,504)

Referent

 26-29

17.2

(258/1,504)

2.24

(1.16, 4.33)

 30-33

11.6

(174/1,504)

4.82

(2.63, 8.81)

 34-37

10.0

(151/1,504)

13.1

(7.47, 22.87)

 ≥38

35.0

(526/1,504)

13.9

(8.20, 23.61)

<0.001