by Christine Haran
Women who are pregnant are generally advised not to take any medication to avoid exposing the fetus to potentially harmful chemicals. So it's not uncommon to find a pregnant woman struggling with a sinus infection because she wants to avoid antibiotics, or a headache because she's not taking aspirin. But asthma is a different story. Studies suggest that women with untreated asthma are more likely to have problems with their pregnancies -- and that women with asthma should be treated for it during pregnancy.
There has been concern that the use of inhaled steroids, which are used to treat persistent asthma, during pregnancy might lead to the birth of infants who are small for their gestational age and have a low birth weight. But a recent study of 474 women, published in the Journal of Allergy and Clinical Immunology, did not find such a link. Below, Michael Schatz, MD, chief of the allergy department at Kaiser Permanente Medical Center in San Diego, and incoming president of the American Academy of Allergy and Immunology, discusses how this information can help pregnant women with asthma feel more comfortable with their decision to treat their lung condition.
How can pregnancy affect breathing in all women?
Interestingly, about 70 percent of women notice shortness of breath during pregnancy. Although one might expect that as the baby grows, in most of those women, it actually starts early in pregnancy. The exact causes aren't known, but it's felt to be related to extra breathing induced by hormones, presumably to provide the extra oxygen that the baby needs. As a result, the woman is breathing deeper during pregnancy and, for many women, it seems to translate into a feeling of shortness of breath. That can, of course, sometimes be confusing in people with asthma. But while any woman can experience shortness of breath during pregnancy, a cough, wheezing or chest tightness is associated with asthma.
Can pregnancy ever trigger asthma for the first time?
It does appear that some women develop asthma for the first time during pregnancy. In some of the women who appear to have asthma for the first time, if you go into some detail in the medical history, you find that they probably had some previous asthma, it just was very mild or very intermittent, so it wasn't noticed until now because the pregnancy seemed to make it worse.
Also, about a third of people with asthma may get worse during pregnancy and anywhere from a quarter to a third may find their asthma gets better during pregnancy. These changes that occur during pregnancy revert most of the time after delivery, or at least within the three months postpartum. So it does appear that it was really the pregnancy that did it.
How can untreated asthma put the baby or mother at risk?
The data suggest that women with asthma may have increased risks of the baby dying, either of a stillbirth or an early death, preeclampsia of the mother, low birth weight of the baby, or prematurity. It appears that it's the more severe and uncontrolled asthma that poses the greatest risk. There is also a risk to the mother of increasing the severity of asthma symptoms or episodes, and even of asthma death.
What medications are used to treat asthma?
The current classification of asthma basically divides patients into people with intermittent asthma and persistent asthma. In people with persistent asthma, the concept is that there are controllers, and rescue medicines. If adequate controller medicines are used, one would not need much rescue medicines. The inhaled steroids are the controller medicine of choice at all levels of persistent asthma during pregnancy and in general.
Intermittent asthma means you have symptoms less than twice a week, wake up in the night from asthma less than twice a month, and have normal pulmonary function tests when not on medicine. The person with truly intermittent asthma just needs the rescue medicines to treat their asthma when symptoms arise. So patients in that category don't need any preventative medicines.
What medications have been of the most concern?
The one medicine for which there have been some associations that are less than reassuring have been the oral steroid medicines. It has been shown that the oral steroids had an effect on intrauterine growth, and in children, there were some data that inhaled steroids could affect growth. The difficulty there is that oral steroids are used for the most severe asthma. So it becomes very difficult to separate out whether it's really the oral steroids or the severe asthma that is increasing risk.
But even intermittent use or short-term use of oral steroids during pregnancy, in some studies, has been associated with some increased risk. So because the oral steroids could do it and because sometimes there are some similar effects of the inhaled steroids, it was felt to be particularly important then to look at that outcome in women using inhaled steroids during pregnancy.
However, in spite of these possible associations, because there are substantial risks of severe uncontrolled asthma to both the mother and the baby, benefit-risk considerations still favor the use of oral steroids when necessary to treat severe asthma during pregnancy.
What do these studies offer pregnant women with asthma?
I think they really help the pregnant woman make the right choice in terms of whether she should be treating her asthma or whether she should be so concerned about safety issues for the baby that she shouldn't treat her asthma with the inhaled steroids.
It's a logical concern, but the data all suggest that even when thinking about the baby, the safest approach is to take the medicines because the risk of the uncontrolled asthma appears to be greater than the risk of the medicine. This study just provides additional information to show that the growth of the baby is not affected by the inhaled steroid.
What can women do about nasal symptoms from allergies?
There have been some studies that suggest that the course of the nasal symptoms during pregnancy, which many women have, is similar to the course of the asthma. It seems that, in women who have preexisting nasal symptoms due to allergy, they can either get better or worse, and there appears to be a real concordance between what the nose does and what the chest does in that regard. So part of the comprehensive treatment of the pregnant woman with asthma is doing the best she can with the nasal symptoms.
The inhaled steroids come in an intranasal form as well and, for nasal allergies, the intranasal steroids are really the most effective single medicine.
Is it OK to use antihistamines or decongestants during pregnancy?
This gets into an area that one never has quite as much information as one would like. With the antihistamines and decongestants, it's not an absolutely clear picture. But there are data from the Swedish Medical Birth Registry suggesting that a couple of the commonly used but somewhat newer antihistamines (loratadine or cetirizine) were used by a relatively large number of women and that did not appear to be associated with any problems. So that's reassuring information.
The decongestant pseudoephedrine has been used for a long time. And there's a little bit of question as to whether there may be some increased risk of a very rare birth defect. We're actually advising people not to take it during the first trimester just in case; that's something that there needs to be more information about.
What is your advice to pregnant women with asthma?
The advice is to get it optimally treated and to work with a provider who understands asthma. There are two basic approaches that are both important in optimizing the mother's health. First identify and avoid triggering factors that can worsen asthma; particularly dust mites, animal dander or mold. And then, since, most patients with persistent asthma can't avoid enough of the triggering factors to have that suffice, to be on appropriate therapy. This is important because of their health and because there are risks from uncontrolled asthma to the baby's health. Our study adds strength to the safety profile of the inhaled steroids, which are clearly the most effective preventative medicine relative to asthma.
Christine Haran has been a health journalist for more than seven years, and her work has appeared in Woman's Day, MAMM Magazine, Bride's Magazine, Publishers Weekly and other publications. In 2003, she received an Excellence in Women's Health Research Journalism Award from the Society for Women's Health Research. Haran has a master's degree in journalism from New York University and a bachelor's degree in English from Skidmore College.
Copyright © Christine Haran. Permission to republish granted to Pregnancy.org, LLC.