Asthma and Pregnancy
By Dr. Catherine A. Clelland, MD
AAIA Newsletter, Spring 2000
For most women, pregnancy is an exciting time. It is the beginning of a new phase in her life, with many changes anticipated. All “mothers-to-be” are concerned about taking any medications, fearing for the health of their unborn baby. In many situations, this is a reasonable concern, but with some underlying conditions, stopping medications can cause more harm than good.
The asthmatic woman who becomes pregnant must consult with her physician to work together to develop a plan to control her asthma. The effect of pregnancy on asthma is variable, and is felt to be due to hormonal effects. We find that in 1/3 of asthmatics, their asthma control improves when pregnant. In 1/3 there is no change, and in 1/3 the control of asthma gets worse. It is difficult to predict who will fall into which group. If a pregnant asthmatic is to get worse, the peak flares tend to occur between 24 and 36 weeks. Future pregnancies will tend to follow similar courses of asthma control. There is also often a worsening of the asthma in the few days following delivery, likely due to hormonal changes at that time. Most asthmatic women will have their asthma return to pre-pregnancy levels of control within 1-3 months after delivery.
The most important fact to remember is that if a pregnant woman’s asthma is well controlled, there are no increased risks of complications. Poor control of asthma can result in a decrease of oxygen for the baby, which may then lead to many complications. This may include premature delivery, low birth weight babies, increases in newborn complications and even death. There are also complications for the mother than can result from poorly controlled asthma. These can include increased blood pressure and toxemia, increased vomiting early in pregnancy, bleeding, complicated labors, and if severe flare, even death of the pregnant woman.
To prevent any of these complications, it is extremely important for the pregnant asthmatic to have an “ASTHMA ACTION PLAN” in place. This involves regular home monitoring of peak flows and medication use. Early in the pregnancy, the physician must evaluate the pregnant asthmatic’s respiratory status, and go over any known triggers. It is important to watch exercise tolerance and asthma symptoms at night. The effects of poor asthma control are often subtle, leading to hidden disability. Because of this, pregnant asthmatics should be under “team management”, with both their respiratory and obstetrical (GP and/or Obstetrician) physicians involvement. Good management includes asthma medication therapy, education and support.
Almost all medications used to control asthma, including inhaled ones, are very safe to use in pregnancy and breastfeeding. It is important to treat the asthma aggressively, because the hazards of uncontrolled asthma are far more likely to harm both mother and baby than any risk of medication. Asthma and allergy medications that are safe to use in pregnancy include the following:
(Webmaster note: due to the age of this article, medications have likely changed – check with your medical advisor)
- inhaled and nasal steroid (e.g., Becloforte, Flovent, Pulmicort, Flonase, Nasacort, etc.)
- oral steroids (e.g., Prednisone)
- inhaled and nasal Cromolyn sodium (e.g., Intal, Cromolyn Nasal)
- “Rescue inhalers” such as salbutamol, terbutaline, metaproterenol and ipatropium
Other symptom control medications, which are okay to use in pregnancy under the supervision of a physician, include:
- chlorpheniramine (antihistamine)
- pseudoephedrine (decongestant)
- guaifenesin, dextromethorphan (cough medications)
As with all medications, it is important to keep close track of frequency and amount used. Annual flu shots are important for all asthmatics, but ideally should be given before pregnancy begins, or in the 2nd or 3rd trimester. For those who receive allergy shots, it is safe to continue, but dose may need to be modified. It is not safe to start new allergy shots when pregnant due to the risk of severe reaction. Most medications can be used with breastfeeding, although with Theophylline, blood levels of the drug should be monitored. Usually less than 1% of Theophylline is found in the breast milk.
If a pregnant asthmatic should experience a severe flare, with peak flows dropping into the “Red Zone” on her “Asthma Action Plan”, treatment in the emergency room is needed immediately, to prevent low oxygen levels in the blood.
The vast majority of well-controlled asthmatics exhibit no symptoms during labour and delivery. For those few who do, the bronchodilator “rescue” medications are all that is needed. Intravenous steroids +/- Theophylline, can also be used at this time if warranted.
If well controlled, the asthmatic woman can expect to have a normal pregnancy. To do this, it is important to follow closely an “ASTHMA ACTION PLAN” with regular visits to her physician(s). It is important to remember the medications required to control asthma are safe and should not cause the mother-to-be any undue concern. With this knowledge, she should be able to enjoy her pregnancy, and look forward to the wonders of birth and parenting.
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This article courtesy of the Allergy/Asthma
Information Association at www.aaia.ca and the Calgary Allergy Network
web site at www.calgaryallergy.ca. May be reproduced for educational,
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