TABLE 3

Mothers' Tobacco Use During Pregnancy and Risk of Apnea: Single Births in Sweden, 1999–2006

Tobacco UseApnea
No.Rate/1000Odds Ratio (95% Confidence Intervals)
CrudeAdjusted Model 1aAdjusted Model 2b
Nonuser7711.5ReferenceReferenceReference
Snuff user263.42.24 (1.52–3.32)2.15 (1.44–3.20)1.96 (1.30–2.96)
Cigarette smoker
    1–9 cigarettes per d942.21.48 (1.20–1.84)1.31 (1.04–1.65)1.08 (0.85–1.37)
    ≥10 cigarettes per d402.41.54 (1.12–2.12)1.49 (1.07–2.08)1.08 (0.76–1.52)
  • Pregnancies with missing information for tobacco use (n = 39 692) were excluded from the analyses as well as dual users, which were too few (n = 480) to give raise to any cases. The rate of apnea among infants to mothers with missing information of tobacco use was 2.7 per 1000.

  • a Model 1 was adjusted for maternal age, height, parity, education, and tobacco use.

  • b Model 2s, in addition to maternal age, height, parity, education, and tobacco use, was adjusted for cesarean delivery, gender, gestational age, and SGA.