Schatz was part of a committee that has developed recommendations to help doctors choose which of about a dozen newly available asthma medicines are best for pregnant women. The recommendations appear in the May issue of the journal Annals of Allergy, Asthma and Immunology . Studies show that in about one-third of women, their asthma gets worse during pregnancy. If existing asthma does worsen, it usually happens between weeks 24 and 36. Hormonal changes may be one potential cause.
Uncontrolled asthma can rob oxygen from the baby.
Some studies have shown asthma increases the baby's risk of premature birth, low birth weight, and stillbirth. Pregnant women with asthma are more at risk for pregnancy-induced high blood pressure. The committee reviewed safety data on 12 drugs introduced since 1993 and found that most are safe to continue using during pregnancy, if the woman had been using them and getting benefit from them prior to pregnancy. A few of the drugs in a class known as leukotriene modifiers are considered somewhat risky for use during pregnancy, because they have been shown to cause problems in animal studies or because they have not been studied extensively in pregnant women. However, these drugs are only used in cases of persistent asthma that cannot be easily treated with other available drugs, according to the committee's paper.