title: Smoking in pregnancy revisited: findings from a large population-based study.
abstract: OBJECTIVE
  The purpose of this study was to characterize the effect of smoking on the incidence of various pregnancy complications.
  
  
  METHODS
  A population-based retrospective analysis with a perinatal database of 170,254 singleton pregnancies was performed. The rate of pregnancy complications was calculated in 4 strata of smokers: Nonsmokers, 1 to 5 cigarettes per day, 6 to 10 cigarettes per day, and >10 cigarettes per day. Logistic regression was used to calculate odds ratios as measures of an association of smoking with various pregnancy complications after correction for confounding factors.
  
  
  RESULTS
  The mean age of the study population was 29 +/- 4.8 years. The odds ratio for preeclampsia was 0.64 (95 % CI, 0.59-0.70), for intrauterine growth restriction was 2.4 (95% CI, 2.34-2.53), and for preterm delivery was 1.2 (95% CI, 1.13-1.28).
  
  
  CONCLUSIONS
  Smoking decreased the incidence of preeclampsia in a dose-effect manner and was shown to increase the rate of intrauterine growth restriction and preterm delivery.
authors.affiliation: Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI 48201, USA.
authors.forename: Ahmad O
authors.initials: AO
authors.lastname: Hammoud
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bujold
authors.forename: Yoram
authors.initials: Y
authors.lastname: Sorokin
authors.forename: Christiane
authors.initials: C
authors.lastname: Schild
authors.forename: Martin
authors.initials: M
authors.lastname: Krapp
authors.forename: Peter
authors.initials: P
authors.lastname: Baumann
mesh_terms: D000293:Adolescent; D000328:Adult; D001724:Birth Weight; D016208:Databases, Factual; D005260:Female; D005317:Fetal Growth Retardation / Q000139:chemically induced / Q000453:epidemiology; D005858:Germany / Q000453:epidemiology; D005865:Gestational Age; D006801:Humans; D016015:Logistic Models; D008499:Medical Records; D016017:Odds Ratio; D011225:Pre-Eclampsia / Q000139:chemically induced / Q000453:epidemiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000139:chemically induced / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*