Concerns regarding harmful effect of asthma medications during pregnancy often result in inadequate treatment of asthma in pregnancy. However, risks caused by poorly controlled maternal asthma may be greater than the potential adverse effects by the asthma medications.
In this study from Mexico, the incidence of preterm delivery was higher among patients with inadequate asthma control during the first part of pregnancy (11.4%) compared with patients with adequate asthma control (6.3%).
Patients who were hospitalized for asthma during pregnancy had a higher incidence of preterm delivery (16.4%) compared with asthmatic women without a history of hospitalization (7.6%).
The authors concluded that there is a substantial risk for preterm delivery caused by poorly controlled maternal asthma.
Asthma control during pregnancy and the risk of preterm delivery or impaired fetal growth. Bakhireva LN, Schatz M, Jones KL, Chambers CD. Ann Allergy Asthma Immunol. 2008 Aug;101(2):137-43.
First-trimester asthma exacerbations may lead to birth defects
Asthma exacerbations during pregnancy can be reduced with a FENO-based treatment algorithm - number needed to treat was 6 (Lancet, 2011).
Maternal Asthma Medication Use and the Risk of Selected Birth Defects. Pediatrics, 2012.
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