Maternal asthma, its control and severity in pregnancy, and the incidence of atopic dermatitis and allergic rhinitis in the offspring.

OBJECTIVE: To evaluate the relationship between maternal asthma, its level of control and severity during pregnancy, and atopic dermatitis (AD) and allergic rhinitis (AR) incidence in children.

STUDY DESIGN: A cohort of 26 265 singletons born to mothers with and without asthma (1990-2002) was constituted by use of 3 Quebec databases. Mothers with asthma had to have received >or=1 diagnosis and >or=1 prescription for asthma 2 years before or during pregnancy. Asthma control and severity during pregnancy was based on validated indexes. ICD-9 codes 691 and 477 allowed us to identify cases of AD and AR.

RESULTS: Maternal asthma during pregnancy was associated with an increased AD risk (adjusted hazard ratio: 1.11, 95% confidence interval: 1.02-1.21), but not of AR (adjusted hazard ratio: 1.04, 95% confidence interval: 0.91-1.20) in children. Asthma control and severity were not associated with either outcome. Maternal AR and intranasal corticosteroid use during pregnancy increased the risk of childhood AR by 70% and 45%.

CONCLUSIONS: Children of mothers with asthma or AR during pregnancy should be closely monitored to diagnose and treat AD and AR as early as possible.