To assess the safety of inhaled beta-agonist bronchodilators during pregnancy, perinatal outcomes in 259 prospectively managed women with asthma using these medications during pregnancy were compared to perinatal outcomes in 101 concurrently followed pregnant subjects with asthma not using inhaled bronchodilators and to perinatal outcomes in 295 concurrently followed pregnant control subjects without asthma. No significant differences between women with asthma using inhaled bronchodilators and subjects not receiving inhaled bronchodilators were found in the following parameters: perinatal mortality, congenital malformations, preterm births, low birth weight infants, mean birth weight, small for gestational age or low ponderal index infants, Apgar scores, labor/delivery complications, or postpartum bleeding. Increased incidences of maternal chronic and pregnancy-induced hypertension and transient tachypnea of the neonate were observed in the pregnancies of subjects with asthma using regular inhaled bronchodilators compared to control subjects, but a logistic regression analysis within the sample of subjects with asthma did not significantly associate the use of inhaled bronchodilators with these outcomes. In the light of the known substantial perinatal risks of severe, uncontrolled asthma and the relatively sparse evidence of human gestational safety for alternative asthma medications, these data support the use of inhaled beta-agonist bronchodilators as part of the management of asthma during pregnancy.