Association between maternal smoking and low birth weight in Switzerland: the EDEN study

Swiss Med Wkly. 2005 Sep 3;135(35-36):525-30.


Purpose: To study the association between maternal smoking during pregnancy and low birth weight (LBW), small-for-gestational-age birth weight (SGA) and preterm birth, and to quantify the population-attributable fractions for these outcomes in Switzerland.

Methods: Data were gathered for all births in the Canton of Vaud (Switzerland) over a twelvemonth period in 1993-1994. LBW was defined as birth weight <2500 g, SGA as a birth weight <10th percentile for gestational age, and preterm birth as a birth occurring at a gestational age <37 weeks. Maternal smoking before and during pregnancy was recorded.

Results: Of a total of 6284 singleton births, 303 (4.8%) were LBW, 731 (11.7%) were SGA, and 364 (5.8%) were preterm. 19.1% of the mothers reported smoking during pregnancy ("smokers"). Mean birth weight, adjusted for maternal age, parity, parents' occupation and neonates' sex and nationality, was lower by 190 g (95% confidence interval: 150-220) in babies of smokers than those of non-smokers. Comparing smokers to non-smokers, the adjusted odds ratios were 2.7 (2.1-3.5) for LBW, 2.1 (1.7-2.5) for SGA and 1.4 (1.1-1.9) for preterm birth. Past smoking was not associated with the outcomes. Maternal smoking during pregnancy accounted for 22% (15-29%) of all LBW babies in the population, 14% (10-18%) of SGA and 7% (1-12%) of preterm births.

Conclusion: Maternal smoking during pregnancy was closely associated with LBW, SGA and preterm birth. A large proportion of these perinatal outcomes could have been prevented in Switzerland if maternal smoking had been avoided.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Fetal Growth Retardation / epidemiology
  • Fetal Growth Retardation / etiology*
  • Humans
  • Infant, Low Birth Weight*
  • Infant, Newborn
  • Infant, Premature*
  • Infant, Small for Gestational Age
  • Logistic Models
  • Male
  • Multivariate Analysis
  • Pregnancy
  • Premature Birth / epidemiology
  • Premature Birth / etiology*
  • Risk Factors
  • Smoking / adverse effects*
  • Smoking / epidemiology
  • Switzerland / epidemiology