Parental smoking and children’s respiratory health: independent effects of prenatal and postnatal exposure
Tobacco Control 2006;15:294-301; Sam Pattenden, Temenuga Antova, Manfred Neuberger, Bojidar Nikiforov, Manuela De Sario, Leticia Grize, Joachim Heinrich, Frantiska Hruba, Nicole Janssen, Heike Luttmann-Gibson, Larissa Privalova, Peter Rudnai, Anna Splichalova, Renata Zlotkowska and Tony Fletcher London School of Hygiene & Tropical Medicine, London, UK, National Centre of Public Health Protection, Bulgaria, Institute of Environmental Health, Center of Public Health, Medical University of Vienna, Austria, National Centre of Hygiene, Medical Ecology & Nutrition, Bulgaria, Department of Epidemiology, Health Authority of Rome, Rome, Italy, Institute of Social and Preventive Medicine of the University of Basel, Basel, Switzerland, Institute of Epidemiology, National Research Centre for Environment and Health, Neuherberg, Germany, Department of Health Informatics and Statistics, Institute of Public Health, Banska Bystrica, Slovakia, Institute for Risk Assessment Sciences, Utrecht University, Netherlands, Harvard School of Public Health, Boston, Massachusetts USA, Urals Regional Center for Environmental Epidemiology, Russia, National Institute of Environmental Health, National Public Health Centre, Budapest, Hungary, Centre of Occupational Medicine, Institute of Public Health Ostrava, Czech Republic, Department of Epidemiology, Institute of Occupational Medicine & Environmental Health, Sosnowiec, Poland
Objectives: Adverse effects have been reported of prenatal and/or postnatal passive exposure to smoking on children’s health. Uncertainties remain about the relative importance of smoking at different periods in the child’s life. We investigate this in a pooled analysis, on 53 879 children from 12 cross-sectional studies—components of the PATY study (Pollution And The Young).
Methods: Effects were estimated, within each study, of three exposures: mother smoked during pregnancy, parental smoking in the first two years, current parental smoking. Outcomes were: wheeze, asthma, "woken by wheeze", bronchitis, nocturnal cough, morning cough, "sensitivity to inhaled allergens" and hay fever. Logistic regressions were used, controlling for individual risk factors and study area. Heterogeneity between study-specific results, and mean effects (allowing for heterogeneity) were estimated using meta-analytical tools.
Results: There was strong evidence linking parental smoking to wheeze, asthma, bronchitis and nocturnal cough, with mean odds ratios all around 1.15, with independent effects of prenatal and postnatal exposures for most associations.
Conclusions: Adverse effects of both pre- and postnatal parental smoking on children’s respiratory health were confirmed. Asthma was most strongly associated with maternal smoking during pregnancy, but postnatal exposure showed independent associations with a range of other respiratory symptoms. All tobacco smoke exposure has serious consequences for children’s respiratory health and needs to be reduced urgently.