Adverse outcomes in pregnancies of asthmatic women: Results from a Canadian population

PURPOSE: There has been little attention paid to asthma complicating pregna ncy. This study is among the few studies that investigated this issue in a large Canadian population (more than two millions of Canadian pregnant wome n). METHODS: We carried out a historical cohort study using hospital discharge data collected by the Canadian Institute for Health Information for fiscal years 1989/90 to 1995/96. RESULTS: A total 2,017,553 obstetric deliveries were included in the analys is. Overall prevalence of asthma among these Canadian women were 0.43%, yie lding a total of 8672 cases of asthmatic mothers. Maternal asthma was assoc iated with all of the adverse pregnancy outcomes examined (including fetal death, preterm labour, hypertensive disorders of pregnancy, gestational dia betes, antepartum hemorrhage, infection of the amniotic cavity, premature r upture of membrane, cesarean delivery, as well as postpartum hemorrhage), a nd adjustment for important confounding factors by multiple logistic regres sion analysis did not change the overall results. These associations were c onsistently observed in teenage and adult mothers, although the association s in teenage mothers tended to be stronger than in adult mothers. CONCLUSIONS: This study confirms that pregnant women with asthma are at sub stantially increased risk for many adverse pregnancy outcomes. For this rea son, pregnant women with asthma are a particularly high-risk group to which extra attention, including increased efforts at education, monitoring, and optimal asthma management, may be appropriate. (C) 2000 Elsevier Science I nc. All rights reserved.