PARENTAL AND NEONATAL RISK-FACTORS FOR ATOPY, AIRWAY HYPERRESPONSIVENESS, AND ASTHMA

Background-Previous studies have not resolved the importance of severa l potential risk factors for the development of childhood atopy, airwa y responsiveness, and wheezing, would allow the rational selection of interventions to reduce morbidity from asthma. Risk factors for these disorders were examined in a birth cohort of 1037 New Zealand children . Methods-Responses to questions on respiratory symptoms and measureme nts of lung function and airway responsiveness were obtained every two to three years throughout childhood and adolescence, with over 85% co hort retention at age 18 years. Atopy was determined by skin prick tes ts at age 13 years. Relations between parental and neonatal factors, t he development of atopy, and features of asthma were determined by com parison of proportions and logistic regression. Results-Male sex was a significant independent predictor for atopy, airway hyper-responsiven ess, hay fever, and asthma. A positive family history, especially mate rnal, of asthma strongly predicted childhood atopy, airway hyperrespon siveness, asthma, and hay fever. Maternal smoking in the last trimeste r was correlated with the onset of childhood asthma by the age of 1 ye ar. Birth in the winter season increased the risk of sensitisation to cats. Among those with a parental history of asthma or hay fever, birt h in autumn and winter also increased the risk of sensitisation to hou se dust mites. The number of siblings, position in the family, socioec onomic status, and birth weight were not consistently predictive of an y characteristic of asthma. Conclusions-Male sex, parental atopy, and maternal smoking during pregnancy are risk factors for asthma in young children. Children born in winter exhibit a greater prevalence of sen sitisation to cats and house dust mites. These data suggest possible a reas for intervention in children at risk because of parental atopy.