Asthma in pregnancy is a relatively common condition. Like all medical conditions in pregnancy, there is hesitation in treating it because of the fear of the effects that medications given to the mother will have on the developing fetus, especially at crucial milestones. Indeed, most obstetricians prefer not to give any medications during pregnancy, when possible.
The perception of many individuals, based on this common obstetrical philosophy and approach, is that it’s preferable to endure the symptoms of conditions like asthma and to “tough it out,” deferring treatment until after delivery of the baby.
Sometimes what is overlooked is the effect untreated disease may have on the fetus. It’s evident that the periods of low oxygen in the blood resulting from uncontrolled asthma will be more detrimental to the growing baby in the asthmatic mother than may be realized.
Some of the adverse effects of uncontrolled asthma in pregnancy are low birth weight and preterm delivery, both undesirable consequences. There is also a greater risk for preeclampsia, a condition that presents with very high blood pressure in the pregnant mother, which includes the threat of bleeding. A recent review published in the Cleveland Clinic Journal of Medicine looked at the consequences of uncontrolled maternal asthma and highlighted the benefits of good adherence to asthma regimens during pregnancy, which outweighed the risks associated with use of these medicines on the growing baby.
For this reason, there are now specific recommended guidelines on how to manage asthma in pregnancy. These guidelines are offered in the 2017 GINA Report, Global Strategy for Asthma Management and Prevention.
The prevalence of asthma in pregnancy ranges between four and eight percent among women in the United States, and it is the most common respiratory illness in pregnancy. In the vast majority of cases, it is not a new condition but rather a worsening of pre-existing asthma. The peak of the worst symptoms of asthma is typically during the end of the second trimester of pregnancy. When asthma occurs in one pregnancy, there is a good change that it will be repeated in the next pregnancy or pregnancies.
In the first trimester, an improvement in the breathing flows is typically noted. The theory is that it’s due to the effect of increasing levels of progesterone on the mother’s ventilation. Subsequently, the elevated hormones cause fluid retention, further swelling of the airways, and narrowing of the inner flow of air. Finally, as the abdomen continues to grow, it puts pressure on the lower part of the chest, resulting in collapse of the alveoli in the bases of the lungs. That’s why the symptoms tend to crop up a bit later in the pregnancy.
The goals of treatment of asthma in pregnancy are established by the National Asthma Education and Prevention Program (NAEPP).
Patients are advised to avoid triggers such as pet dander and dust mites, which can occur from sweating during the night and building the perfect environment for mites to accumulate on sheets and pillowcases. It is also wise to avoid pollen, smoke, mold, and perfumes.
If medications are needed for gastric reflux, the first line of drugs recommended is antacids or sucralfate. Pregnant women are advised to avoid histamine blockers like Pepcid and Zantac, as well as proton pump inhibitors (PPIs) like Omeprazole, unless the symptoms are resistant to the initial treatments recommended.
For rhinitis or nasal congestion, it’s safe to use nasal steroid inhalers (their action is local) as well as Montelukast (Singulair), a leukotriene antagonist. Medications to be avoided are those from the pseudoephedrine family (often seen in over-the-counter cold medications). Ironically, people feel that no harm can result from medications that can be obtained without prescription. Just because you can get it without a prescription does not make it safe for use in pregnancy.
Diagnostic skin tests for allergies should be avoided during pregnancy, although maintenance allergy shots (if already started before pregnancy) can continue safely during pregnancy.
In 2015, the Food and Drug Administration (FDA) replaced the existing risk classification of drugs in pregnancy — A (safest), B, C, and X (contraindicated) — and gave each drug its own individual summary of risk data. This method, although more complete, may actually be more confusing, as there is less consistency, and it can be subject to misinterpretations. This makes it more imperative for every individual to have an in depth discussion with the treating doctor about any treatment given.
With regard to asthma medication specifically, inhaled corticosteroids are still the mainstay for maintenance. There’s no data to suggest that the combination of long-acting bronchodilators such as Advair, Symbicort, Dulera, and Breo with inhaled steroids is less safe than the inhaled steroids alone. Patients should therefore remain on regimens in use before the pregnancy, if the medications were tolerated well and controlled symptoms.
Theophylline and the injectable Omalizumab (Xolair) should be avoided because they require more intensive monitoring, and they have been associated with teratogenic effects.
Systemic steroids such as prednisone can be used as a drug of last resort if asthma is not well controlled with the other mentioned medications. The biggest risk when using oral prednisone is cleft palate in infants if used in the first trimester of pregnancy. Preeclampsia, low birth weight, and preterm deliveries have also been associated with steroid use.
These same dangers have the potential to occur if asthma symptoms are untreated. The goal in pregnancy is to avoid low blood oxygen levels in the mother, which poses the greatest risk to the baby.
It must be emphasized that the best scenario is close collaboration between the primary care physician familiar with the asthma sufferer before pregnancy, the obstetrician treating the pregnancy, and the patient who will be first to notice warning symptoms of out-of-control asthma. This optimal relationship will allow the necessary closer monitoring of the mother and best outcomes for the developing fetus.
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Eli Hendel, M.D., is a board-certified internist/pulmonary specialist with board certification in Sleep Medicine. An Assistant Clinical Professor of Medicine at Keck-University of Southern California School of Medicine, and Qualified Medical Examiner for the State of California Department of Industrial Relations, his areas include asthma, COPD, sleep disorders, obstructive sleep apnea, and occupational lung diseases. Favorite hobby? Playing jazz music. Find him on Twitter @Lung_doctor.