The safety of asthma and allergy medications during pregnancy.

Background: Although no asthma or allergy medications can be considered proven safe for use during pregnancy, these medications are often used to prevent the potential direct and indirect consequences of uncontrolled asthma or allergy.
Objective: The safety of asthma medications, antihistamines, and decongestants was assessed in a prospectively monitored cohort of 824 pregnant women with and 678 pregnant women without asthma.
Methods: Medications used since conception were recorded on each subject's initial visit (< 28 weeks' gestation). Thereafter, diary cards for medications were completed by the patient through the time of delivery. Perinatal outcomes were compared in exposed versus unexposed individuals. A multivariate analysis accounted for the potential effects of age, parity, smoking, race, weight gain during pregnancy, maternal pulmonary function, acute asthmatic episodes, and multiple medication exposure.
Results: No significant relationships were identified between major congenital malformations and first trimester or any exposure to beta-agonists, theophylline, cromolyn, corticosteroids, antihistamines, or decongestants. In the multivariate analyses, oral corticosteroids were independently associated with preeclampsia (odds ratio = 2.0, p = 0.027), but no other independent associations were observed between asthma or allergy medications and adverse perinatal outcomes.
Conclusion: Use of most common asthma and allergy medications during pregnancy was not associated with increased perinatal risks. Maternal use of oral corticosteroids was independently associated with the occurrence of preeclampsia in this study, although the mechanism of this association is not clear. However, because prior observations suggest that severe asthma may be associated with maternal and/or fetal mortality, risk-benefit considerations still favor the use of oral corticosteroids when indicated for the treatment of asthma during pregnancy.