TABLE 1

Tobacco Use During Pregnancy and Rates (%) of Maternal and Neonatal Characteristics: Single Births in Sweden, 1999–2006 (N = 609 551)

Maternal and Neonatal CharacteristicsNonuser (n = 503 460)Snuff User (n = 7599)SmokerDual User (n = 481)
1–9 Cigarettes per d (n = 41 391)≥10 Cigarettes per d (n = 16 928)
Age, ≤19 y1.11.9a6.4a3.6a4.2a
Height, ≤159 cm8.611.3a11.8a12.4a13.5b
Multiparity, ≥44.27.3a8.0a18.5a10.0a
Education, ≤9 y5.611.3a27.0a34.0a25.6a
Cesarean delivery15.418.2a16.5a16.6a16.4
Gestational age, ≤36 wk4.65.8a6.1a7.3a5.6
SGAc2.22.44.7a5.8a5.6a
  • Pregnancies with missing information: 39 692 for tobacco, 13 633 for height, and 9290 for education.

  • a P < .0001 versus nonusers.

  • b P < .001 versus nonusers.

  • c SGA was defined as >2 SDs below the mean birth weight for gestational age according to the gender-specific Swedish fetal growth curve.19