Health

Asthma and pregnancy: don't abandon the pump!

A large number of asthmatic women who become pregnant stop taking their asthma treatments—often with approval from their doctors—in order to avoid any effect of the medication on the fetus. “It now appears that this is wrong,” says Lucie Blais, a Researcher in the Université de Montréal Faculty of Pharmacy. One of our studies has shown that health problems arise from uncontrolled asthma, not the use of asthma drugs.”

For the past two years, the epidemiologist has been doing research on pregnant women who suffer from asthma. Using data from the Health Insurance Board, the Ministry of Health and Social Services, and the Québec Statistics Institute, she has gathered information on 21,000 pregnant women who consulted a physician in Québec for their asthma or purchased prescription drugs to treat it between 1990 and 2002. This sample is the largest ever established on the subject. “Very little scientific literature exists on the risks and advantages of drugs used to treat asthma during pregnancy, the researcher notes. This can be explained as follows: clinical research that accompanies the marketing of drugs systematically excludes pregnant women. As a result, our knowledge in this area is very limited.” Yet asthma is a chronic disease that affects from 7% to 10% of women. The rare studies of asthmatic pregnant women have shown that they ran a higher risk of having low birthweight babies or suffering from hypertension during their pregnancy. This condition is closely monitored by attending physicians, because hypertension can lead to pre-eclampsia or eclampsia, disorders that can be fatal for both infant and mother.

"Our study led us to a conclusion that was initially very perplexing for us: hypertension in pregnancy will affect 30% more women who inhale corticosteroids during pregnancy,” Ms Blais notes. “But when we analyzed of the data we turned up a fallacy. In reality, the risk is related to lack of control of the asthma. This means that women who stopped taking their medication, or women for whom the medication has no effect risk having hypertension during pregnancy. Those who control their asthma with drugs have no higher risk than anyone else.”

At present, four kinds of medication are used to control asthma: inhaled corticosteroids (Flovent), short acting ß 2 adrenergic agonist bronchodilators, and antileucotrienes. They are all administered by spray (pump) except for the latter, which is taken in pill form. The databank, which includes a control group of 44,000 non-asthmatic women, will be used for long-term epidemiological studies, since it will be updated every two years. In the coming year, Lucie Blais's studies will focus on two new aspects of the asthmatic condition in pregnant women: the incidence of congenital malformations and the effects of stopping treatment.