Smoking, nicotine and tar and risk of small for gestational age babies.
OBJECTIVE
To assess the effect of maternal smoking and environmental tobacco smoke (ETS) on risk of small for gestational age infants (SGA).


METHODS
Case-control study of 844 cases and 870 controls.


RESULTS
Maternal smoking in pregnancy was associated with an increased risk of SGA (adjusted odds ratio (OR)= 2.41; 95% confidence interval (CI) = 1.78, 3.28). We could not detect an increased risk of SGA with paternal smoking, or with other household smokers when the mother was a non-smoker, but did find an increased risk with exposure to ETS in the workplace or while socializing. Infants of mothers who ceased smoking during pregnancy were not at increased risk of SGA, but those who decreased but did not stop remained at risk of SGA. There was no evidence that the concentration of nicotine and tar in the cigarettes influenced the risk of SGA.


CONCLUSIONS
Maternal smoking in pregnancy is a major risk factor for SGA. This study suggests that mothers should be advised to cease smoking completely during pregnancy, and that a reduction in the number of cigarettes smoked or smoking low tar or nicotine concentration cigarettes does not reduce the risk of SGA.
Mitchell
E A
EA
Department of Paediatrics, University of Auckland, New Zealand. e.mitchell@auckland.ac.nz
Thompson
J M D
JM
Robinson
E
E
Wild
C J
CJ
Becroft
D M O
DM
Clark
P M
PM
Glavish
N
N
Pattison
N S
NS
Pryor
J E
JE
D000704:Analysis of Variance; D016022:Case-Control Studies; D015331:Cohort Studies; D005314:Embryonic and Fetal Development / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D016015:Logistic Models; D018811:Maternal Exposure; D015999:Multivariate Analysis; D009520:New Zealand / Q000453:epidemiology; D009538:Nicotine / Q000009:adverse effects*; D016017:Odds Ratio; D011247:Pregnancy; D015995:Prevalence; D012016:Reference Values; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D013638:Tars / Q000009:adverse effects*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
D013638:Tars; D014028:Tobacco Smoke Pollution; D009538:Nicotine