A retrospective study of the relationship between childhood asthma and respiratory infection during gestation

Background Wheeze in children has been found to be associated with prior an tepartum haemorrhage and raised levels of IgE in cord blood, and acute whee zing episodes are intimately linked with respiratory viral infections. Objective To assess the relationship between maternal presentation with res piratory tract infections in pregnancy and childhood asthma, taking into ac count factors which could affect presentation. Methods This was a case-control study of 200 asthmatic children, 5-16-year- old, age-matched with one control, having no recorded history of wheeze. Da ta on respiratory tract infections, maternal wheeze, atopy and smoking was collected from primary care records. Deprivation score was assessed accordi ng to small residential areas and subjects were equally distributed between four general practices in Plymouth, UK. Results Presentation with respiratory tract infections during pregnancy was significantly associated with childhood asthma (OR 1.69, 95% confidence in terval 1.05-2.77, P=0.03). The association was marginally stronger for infe ctions in the first trimester (OR 2.30, 95% CT 1.05-5.41, P =0.04) and for those with cough during pregnancy (OR 2.24, 95% CI 1.13-4.22, P=0.007). The associations remained significant after allowing for the effect of the ind ependent variables (gender, maternal smoking, maternal wheeze, allergic rhi nitis, eczema, asthma treatment in pregnancy and deprivation [Townsend] sco re), using multiple logistic regression analysis (ORs and 95% CIs 1.91, 1.1 4-3.22; 2.32, 1.01-5.34 and 2.29, 1.17-4.48, respectively). There was also an association between numbers of presentations with respiratory infections and childhood asthma (test for trend, P=0.02). Conclusions This study has shown an association between presentation with r espiratory infection during gestation and childhood asthma. The results wer e not affected by the other independent variable factors studied and theref ore provide some evidence to support the theory that respiratory viruses ma y be implicated in the aetiology of asthma.