Fetal and postnatal exposure to tobacco smoke and respiratory health in children.

The aim of this paper was to find out whether fetal exposure to environmental tobacco smoke (ETS), as compared to postnatal ETS exposure, is an independent risk factor for respiratory symptoms and diseases in younger schoolchildren. The cross-sectional epidemiological study comprised population of 1,561 Polish schoolchildren, aged 9-11 years. Information on the exposure to tobacco smoke and other sources of indoor air pollution at home, respiratory and allergic health status, and socio-economic status of the family was obtained by questionnaire survey. The respiratory health status was described by presence of wheezing, attacks of dyspnoea (noted during the last year or ever), bronchitis, wheezy bronchitis and asthma, ever diagnosed by a physician. Multivariate logistic regression analysis with adjustment for age, sex, area of residence, household density, damp and mould stains found at home, use of coal-fired stove, co-habitant pets, mother's education and paternal current and past smoking habit was used to assess the effect of fetal and postnatal exposures on respiratory health outcomes. The results of the multivariate analyses revealed statistically significant associations between fetal exposure to ETS and wheezing ever: log OR = 1.4 (95% CI: 1.0-2.0), attacks of dyspnoea ever: log OR = 1.8 (95% CI: 1.1-2.9), bronchitis: log OR = 2.1 (95% CI: 1.5-2.9), and wheezy bronchitis: log OR = 1.8 (95% CI: 1.1-2.9). The effect of postnatal ETS was statistically significant only for bronchitis: log OR = 1.4 (95% CI: 1.1-1.9). The results of our study showed that fetal exposure to tobacco smoke is an independent risk factor for symptoms of wheeze and wheezy bronchitis in schoolchildren when compared to postnatal ETS exposure.