Respiratory effects of early childhood exposure to passive smoke: Fid-Bau Portal

Respiratory effects of early childhood exposure to passive smoke

Stern, Bonnie / Raizenne, Mark / Burnett, Richard

AbstractThe effects of early exposure to maternal smoking were examined in a cohort of 4003 Canadian school children aged 7 to 12 years. Standard respiratory questionnaires were completed by parents: spirometry was performed in the schools. Children whose mothers smoked regularly during pregnancy and during the child's first two years of life were almost twice as likely to be hospitalized for a respiratory illness before two years of age than those children whose mothers did not smoke (odds ratio = 1.85, p < 0.001). Chronic cough and asthma were also significantly more frequent among exposed children (odds ratio = 1.45, p < 0.01, for chronic cough; odds ratio = 1.43, p < 0.01, for asthma). A 1.07% decrement in forced expiratory volume in one second FEV1 (p < 0.006) was also observed in exposed children, as compared with those who were unexposed. Thus, maternal smoking during pregnancy and during the first two years of a child's life is a risk factor for chronic cough and asthma and decreased FEV1 in preadolescent childhood. Hospitalization before the age of two years was also examined as a risk factor for subsequent respiratory health outcomes and was found to be significantly associated with increased rates of respiratory symptoms and illnesses, and with decreased pulmonary function in later childhood. Since maternal smoking during pregnancy and during the child's first two years almost doubles the risk of being hospitalized before age two for a chest illness, it contributes indirectly to the higher rates of respiratory symptoms and illnesses and decreased pulmonary function observed in these children.