Skip to main content

Table 2 Risk ratios (RR) and 95% confidence intervals (CI) for the associations between opium and tobacco use during pregnancy and risk of small for gestational age at birth

From: Opium use during pregnancy and infant size at birth: a cohort study

 

Pregnancies

Small for gestational age a

Crude

Adjusted b

N

N (%)

RR (95% CI)

RR (95% CI)

Opium

 Unexposed

905

99 (10.9)

Reference

 Exposed

887

154 (17.4)

1.59 (1.26–1.99)

1.69 (1.34–2.13)

Tobacco and opium

 Unexposed

905

99 (10.9)

Reference

 Exposed to opium only

677

115 (17.0)

1.59 (1.22–2.06)

1.71 (1.34–2.18)

 Exposed to tobacco and opium

210

39 (18.6)

1.58 (1.10–2.28)

1.62 (1.13–2.30)

Restricted to term pregnancies

Opium

 Unexposed

850

93 (10.9)

Reference

 Exposed

798

132 (16.5)

1.46 (1.15–1.86)

1.58 (1.23–2.02)

Tobacco and opium

 Unexposed

850

93 (10.9)

Reference

 Exposed to opium only

616

97 (15.7)

1.43 (1.11–1.85)

1.58 (1.22–2.04)

 Exposed to tobacco and opium

182

35 (19.2)

1.57 (1.10–2.24)

1.58 (1.09–2.29)

  1. aSmall for gestational age was defined as a birth weight below the 10th percentile for appropriate gestational age, based on a sex-specific global reference for birth weight [13]
  2. bAdjusted for: maternal age, height, BMI, parity, husband’s occupation, and residential place