In utero and childhood exposure to parental tobacco smoke, and allergies in schoolchildren

Abstract

Among early-life environmental factors, parental smoking (ETS) has been associated with adverse respiratory outcomes in children. The aim of the study was to evaluate whether parental smoking might lead to asthma and allergies taking into account family history of asthma, personal atopy, breast feeding as confounders and owing pets and day-care during the first 6 months of life as modifiers. About 9000 children of fourth and fifth grade were selected in six cities of France. About 7798 answered an epidemiological questionnaire, underwent a medical examination including skin prick test positivity to common allergens, skin examination for eczema, and run test to assess exercise-induced asthma (EIA). Prevalence of allergies was, respectively, 25.2% for eczema, 12.9% for rhinitis, 9.9% for asthma and 25% for atopy. About 8.3% had an EIA. About 21.6% of children were exposed to maternal tobacco smoking during pregnancy. Maternal smoking, in utero and later, was significantly related to lifetime wheezing (odds ratio (OR): 1.24[1.10-1.56]) and asthma (OR: 1.22[1.04-1.66]). There was no association between atopy, rhinitis, eczema and parental smoking, respectively. ETS remains a risk factor of wheezing in childhood. Counselling parents of children to quit smoking still remains a public health policy.

Allergic Rhinitis and its Impact on Asthma (ARIA) 2008*

“…Smoking during pregnancy affects fetal lung development especially when there is a family history of asthma and hypertension during pregnancy (1866,1867) and causes abnormal airway function (1868). Effects of ETS due to parental smoking on wheezing in early childhood have been described in epidemiologic studies (1869)(1870)(1871)(1872)(1873) but few have made an effort to discriminate between the effects of prenatal and postnatal exposure. Recent studies suggest that smoke exposure in utero may be at least as detrimental to respiratory health in early life as postnatal exposure to ETS (1874).…”

“…Another study suggested that in utero exposure is more important (1875). There is not usually any association between atopy, rhinitis, eczema and parental smoking (1873). Counseling parents to stop smoking still remains an important policy.…”

Associations between indoor environmental smoke and respiratory symptoms among preschool children in Shanghai, China

“…Studies of environmental tobacco smoke (ETS) have found that it to be a risk factor for children's respiratory health in many developed countries or regions, for example in Italy [2], France [3], Portugal [4], Greece [5], Bulgaria [6], Singapore [7], Japan [8], USA [9][10][11] and Taiwan, China [12]. A study In Shanghai also found similar adverse effects from ETS [13].…”

Systems Medicine Approaches for the Definition of Complex Phenotypes in Chronic Diseases and Ageing. From Concept to Implementation and Policies

“…These risk factors may already act in utero and in early life [39]. Any study in the prevention and control of NCDs should consider these risk factors.…”