Dose response association of pregnancy cigarette smoke exposure, childhood stature, overweight and obesity.
BACKGROUND
The combined dose response effects of pregnancy cigarette smoke exposure on childhood overweight, obesity and short stature have not been reported.


METHODS
A community based cross-sectional survey of 3038 children aged 5-11 years from 15 primary schools in Merseyside, UK. Self-completed parental questionnaires were used for family characteristics, socio-economic status and parental smoking practices. Children were measured for height and weight and z-scores calculated for parental smoking categories.


RESULTS
Of 689 (34.0%) mothers who smoked during pregnancy 50.5% smoked ten or more cigarettes daily (heavy smokers). Children of maternal non-smokers had prevalence estimates for overweight, obesity and short stature of 25, 9.6 and 3.2%, respectively. Prevalence estimates were higher in children of mothers who were heavy smokers during pregnancy, 31.5% (P = 0.001), 15.6% (P < 0.001) and 5.5% (P = 0.001), respectively. Mean height for age z-scores was lower among heavy maternal (P < 0.001) and paternal smokers (P < 0.01) compared to non-smokers. Childhood overweight, obesity or short stature were all associated with heavy maternal smoking during pregnancy (all P < 0.001). Mean body mass index (BMI) z-scores were higher in boys of mothers who smoked (P = 0.043). The adjusted odds ratio for short stature in children of heavy maternal smokers was 2.76 (95% CI 1.21-6.33) and 4.28 (1.37-13.37) if both parents were heavy smokers. The adjusted OR for obesity in children of maternal smokers was 1.61(1.19-2.18). The population attributable risk for short stature was 8.8% (1.1-22.7) for heavy maternal smokers.


CONCLUSIONS
A dose-response association was observed between pregnancy smoking exposure, short stature and obesity.
Child and Reproductive Health Group, Liverpool School of Tropical Medicine, Liverpool, UK.
Gibby
G
Koshy
Ali
A
Delpisheh
Bernard J
BJ
Brabin
D001827:Body Height; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D016017:Odds Ratio; D050177:Overweight / Q000453:epidemiology; D010290:Parents; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D015995:Prevalence; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires