THURSDAY, Oct. 2, 2003 (HealthDayNews) -- Pregnant women with asthma can breathe easy about using mild or moderate medications to control their symptoms -- doing so isn't likely to harm your baby.
In fact, new research shows that leaving your asthma untreated is more likely to cause both you and your newborn harm.
However, the study also finds women who use more powerful asthma drugs during pregnancy -- such as oral steroids -- risk giving birth prematurely.
In the study in the October issue of Obstetrics and Gynecology, Yale researchers found women who didn't report or treat their asthma symptoms during pregnancy were at increased risk for intrauterine growth retardation (IUGR) -- a problem that contributes to smaller, underdeveloped babies. The more severe the asthma symptoms, the more severe the problems were for their baby.
"There is definitely a group of women who are not being diagnosed and not being managed properly and they are running into an increased risk in terms of their babies -- more so than if they were taking medication," says study author Michael Bracken, a professor of epidemiology at Yale University School of Medicine.
Those women who did control their asthma symptoms using mild-to-moderate drugs known as beta 2 agonists did not share that risk. These treatments include inhaled medications such as albuterol, isoproterenol and terbutaline.
"There was concern expressed about the safety of beta 2 agonists, so this study is reassuring in that respect," Bracken adds.
But, the study also showed that women who used more potent asthma drugs during pregnancy, such as oral steroids or theophylline, were at increased risk for pre-term delivery.
"These drugs should only be used to manage the most severe symptoms. And when that is the case, the risks may outweigh the benefits," Bracken says.
Asthma expert Dr. Jonathan D. Field, who was not involved in the research, says this study is important because it gives doctors a window into not only the effects of certain asthma medications on pregnancy, but also the effects of skipping treatment altogether.
"Women are often concerned about taking medication during their pregnancy, because of any perceived dangers to their baby. But there are rarely any studies to show the dangers linked to not treating a particular problem during pregnancy, such as asthma. And this study does just that," says Field, director of Pediatric Allergy and Asthma Clinic at New York University Medical Center.
As a result, he says, the study offers women some comforting news about not only the safety of certain asthma drugs, but also the safety of treating versus not treating your asthma during pregnancy.
"It really gives us a strong comparison -- using a large group of women -- and I think it will help reduce many fears that women may have about using medications to control their symptoms," Field says.
The study included 873 pregnant women with a history of asthma. Of this group, 778 women reported asthma symptoms during their pregnancies and took various types of medications.
A comparison group consisted of 1,333 pregnant women with no history of asthma symptoms, including 884 women who were not diagnosed with asthma and reported no symptoms, and 449 women with asthma symptoms, but no previous diagnosis of the condition.
After comparing the pregnancy outcomes of both groups, the researchers concluded that premature birth -- a problem once thought to be associated with asthma -- was not linked to the condition. More specifically, the researchers found that neither the severity of asthmatic symptoms, nor the symptoms themselves, played any part in pre-term birth.
But the researchers did find women who used oral steroids, or the asthma treatment known as theophylline, experienced an increase in premature birth. For those using oral steroids, babies were born 2.22 weeks early; for those using theophylline, babies were born 1.11 weeks early.
In addition, the researchers found that in women who were not taking medication for asthma, there was a 24 percent increased risk for IUGR. The worse the asthma symptoms, the greater the risk for IUGR. Risks were greatest in women who had asthma symptoms but were never diagnosed with the condition.
"Our observations support the current guidelines for treating asthma during pregnancy, and actually present better evidence for those guidelines than was there before they were developed," Bracken says.
Bracken suggests women and their doctors be on the lookout for symptoms of asthma, particularly if the problem has not been previously diagnosed.
"We should be trying to find these women, diagnose them and medicate them properly. And part of the workup now, for pregnant women, should be to inquire about asthma symptoms and then act accordingly," he says.
For Field, the study is a reliable validation of the need to treat asthma symptoms during pregnancy.
"I think the real message here is that pregnant women should not be afraid to treat their asthma symptoms with some of the most commonly used drugs. And they should also report any symptoms of asthma to their doctor during pregnancy, even if they have never been diagnosed before," he says.
Common asthma symptoms include difficulty breathing, shortness of breath, wheezing, and coughing while exercising, or directly after you stop.