Pregnancy can affect the course of asthma, and asthma can affect pregnancy
outcomes. Asthma course may improve, worsen, or remain unchanged during pre
gnancy. The mechanisms involved have not been defined, and the course in an
individual woman is largely unpredictable. Therefore pregnant women with a
sthma must be followed up particularly closely so that any change in course
can be matched by an appropriate change in therapy. The data also suggest
that asthma is associated with increased frequencies of adverse pregnancy o
utcomes. The mechanisms of this are not totally clear either, but some data
support the hypothesis that improved pregnancy outcomes are associated wit
h well-controlled disease, The risk of using medications to control asthma
during pregnancy appears to be much less than the risk of adverse outcomes
related to severe uncontrolled asthma.