Poor asthma control during pregnancy has been shown to be associated with preterm delivery, low birth-weight babies, and even congenital malformations but its consequences on the child’s respiratory health beyond the neonatal period has yet to be determined. We have recently conduced a double-blind, parallel-group,randomised controlled trial the Managing Asthma in Pregnancy (MAP) study to determine the efficacy of personalised asthma management and demonstrated that the frequency of asthma exacerbations was reduced by 50% during pregnancy when management was guided by inflammometry (management algorithm taking into account the fraction of exhaled nitric oxide concentration (FeNO) as a non-invasive surrogate marker for airways inflammation).
Bronchiolitis is the most common and severe virus-induced wheezy lower respiratory tract infection (LRTI) in the first year of life and recurrent LRTI are associated with a considerable risk to have allergic asthma in childhood, particular when they occur in infants at high risk for allergic hypersensitivity (atopy) and when they are caused by rhinovirus (RV). Importantly, infants born to asthmatic mothers (66% atopic) managed with inflammometry had a dramatically reduced relative risk of suffering from recurrent episodes of bronchiolitis in the first year of life as compared to the control group (Odds ratio=0.08, p=0.019). These forerunner studies identify an effective two-win prevention strategy for asthmatic mothers and their babies that greatly reduced the overall burden of asthma and LRTI. However it is unknown whether the association between better asthma management during pregnancy and reduced susceptibility to recurrent LRTI in the offspring is related to antiviral host responses and the development of atopy and airways inflammation in childhood, which are all considered as crucial factors in the immunopathogenesis of asthma. Follow-up of this worldwide unique birth cohort for the first 6 years of life is a historical opportunity to determine these relationships. Identifying the molecular and cellular mechanisms that link asthma and virus infections during pregnancy to susceptibility to LRTI in infancy and potentially atopy and airways inflammation in childhood may directly translate into novel preventative strategies for better health outcomes by reducing the enormous disease burden caused by allergic asthma.
OVERALL HYPOTHESIS: Better asthma management during pregnancy affects antiviral host responses and reduces the risk for atopy and the degree of airways inflammation in the offspring