Background: For the past 40 years, evidence has been accumulating on the effects of passive smoking on the fetus and on children. Over this period, research methods have become more precise and accurate, with confounding factors controlled for and actual exposure to smoke measured and validated by cotinine tests on body fluids. This review follows the progress of these studies and assesses the weight of evidence for various health risks of passive smoking on children from before birth to adolescence.
Methods: Nearly 200 research papers published worldwide were reviewed.
Results: Effects of maternal smoking on the fetus include low birthweight, increased risk of spontaneous abortion, and perinatal death. The effect of maternal smoking on breast feeding is still enigmatic. Breast-fed infants of mothers who smoke appear to be protected against respiratory diseases but are subjected to chemicals from the smoke transferred in the milk. It is difficult to separate prenatal and postnatal effects with regard to growth, development, and lung function retardation. There is, however, a definite increase in respiratory diseases, otitis media, and minor ailments, which are unequivocally related to parental, especially maternal, smoking.
Conclusions: There is now sufficient evidence that health problems in children are related to maternal, and to a lesser degree paternal, smoking during pregnancy, and, after birth, to exposure to environmental tobacco smoke (ETS) in the home and daycare centers. Exposure to ETS should be noted on pediatric patients' problem lists and addressed at each visit.