[Risk factors in the pre-, perinatal and early life (first year) for wheezing in young children].

In recent years some studies have focused attention on the contribution of early life risk factors in the pathogenesis of asthma and wheezing. In our study we tested the hypothesis that wheezing in childhood is not a single disorder and that different wheezing phenotypes (called transient early wheezing, persistent wheezing and late-onset wheezing) are associated with different risk factors. We evaluated the association between pre, perinatal and early life (1st year) risk factors and different wheezing phenotypes in children 6-7 years old enrolled in the SIDRIA-2 project. Maternal smoking in pregnancy is associated with early and persistent wheezing; prematurity, child's admission to hospital shortly after birth for respiratory problems, indicators of respiratory infections during the child's first year of life are associated with early wheezing. An increase in childhood infections from contact with siblings or day care attendance is a risk factor for early wheezing but protective against late-onset wheezing, while an opposite pattern was observed for breastfeeding. Finally, mould or dampness in the child's bedroom during his first year of life is associated with all wheezing phenotypes. The risk factors studied are differently associated with different wheezing phenotypes.