The unborn smoker: association between smoking during pregnancy and adverse perinatal outcomes.
OBJECTIVE
To evaluate a possible dose-response relationship between active maternal smoking during pregnancy and adverse perinatal outcome.


METHODS
Retrospective cohort study.


METHODS
Population-based in Montreal, Quebec, Canada.


METHODS
Women who gave birth to a liveborn or stillborn infant during the period of January 2001 to December 2007.


METHODS
Active smokers of different daily cigarette consumption (n=1646) were identified through maternal self-reporting. The reference group comprised 19,292 non-smoking women who delivered during the same period.


METHODS
Birth weight, preterm delivery rate, fetal and neonatal mortality and morbidity, and congenital malformations.


RESULTS
Preterm delivery rate was significantly higher in the smoking group compared with controls (22.2% vs. 12.4%, P<0.05), as was intrauterine fetal demise (1.4% vs. 0.3%, P<0.05). Newborns of active smokers were more likely to weigh less (3150±759 g vs. 3377±604 g, P<0.05), suffer from respiratory distress syndrome (2.5% vs. 1.3%, P<0.05), suffer from a cardiac malformation (1.5% vs. 0.8%, P<0.05), and die (neonatal death 1.2% vs. 0.6%, P<0.05). A dose-response relationship was demonstrated between levels of daily cigarette smoking and several adverse outcomes. Using multiple regression models, smoking was found to be an independent predictor of preterm delivery (odds ratios (OR) 1.9, 95% confidence intervals (95%CI) 1.6-2), and intrauterine fetal demise (OR 2.4, 95%CI 1.4-4.2).


CONCLUSIONS
Any amount of daily smoking appears to harm the fetus and newborn. As pregnancy may be a "window of opportunity" for behavioural changes, efforts to promote smoking cessation should be encouraged.
Elad
E
Mei-Dan
Asnat
A
Walfisch
Boaz
B
Weisz
Mordechai
M
Hallak
Richard
R
Brown
Alon
A
Shrim
D001724:Birth Weight; D015331:Cohort Studies; D000013:Congenital Abnormalities / Q000209:etiology; D005260:Female; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D016017:Odds Ratio; D011247:Pregnancy; D011256:Pregnancy Outcome; D047928:Premature Birth; D011297:Prenatal Exposure Delayed Effects / Q000209:etiology*; D011792:Quebec / Q000453:epidemiology; D012127:Respiratory Distress Syndrome, Newborn / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D050497:Stillbirth