Grant: Operating Grant

Asthma is one of the most common chronic diseases affecting pregnancy. Several studies have evaluated whether asthmatic women are more at risk to have a baby with a congenital malformation and only two of them found an increased risk among asthmatic women. Only one of these studies included enough women to be able to study the risk of specific congenital malformations. Discrepancies between studies can be explained by the fact that almost all studies had too few women in it to conclude with precision. There is thus a need for a large study to evaluate with precision whether or not asthmatic women are at increased risk of specific congenital malformations. The primary objectives of this study are to estimate whether the fetus of asthmatic pregnant women are more at risk of cardiac malformations, malformations of the respiratory system, malformations of the nervous system, cleft palate/lip and Spina bifida than fetuses of non-asthmatic women. If maternal asthma is found to be associated with congenital malformations, two secondary objectives will be perused: 1) To evaluate whether or not asthma medications play a role in the increased risk and 2) To evaluate whether women who have a severe asthma exacerbation requiring hospitalization during the first trimester are more at risk of congenital malformations. A large cohort of asthmatic and non-asthmatic women will be reconstructed from the linkage of administrative databases of the province of Quebec, namely the hospital database, the medical and pharmaceutical services database and the birth and death registries. This study will provide major advances in our understanding of the impact of maternal asthma on the risk of specific congenital malformations. If asthmatic women are found to be at increased risk of some specific congenital malformations and not of others, it will allow more efficacious surveillance of the fetus during pregnancy and effective interventions to improve the health of the fetus.