The most appropriate management is to continue the current drug regimen. As in all patients with asthma, treatment of asthma during pregnancy should aim for optimal control, and a regimen that adequately controls asthma should be continued. Controlled asthma ensures safety for the fetus as well as the mother and reduces the risk for preeclampsia and preterm birth. Inhaled glucocorticoids are considered safe in pregnancy, and abundant long-term safety evidence exists for budesonide. Short-acting β₂-agonists are considered safe in pregnancy, and existing data for long-acting β₂-agonists are reassuring that these agents are safe as well. The leukotriene antagonist montelukast is also considered safe in pregnancy. In this patient, who has a history of reduced lung function, it is appropriate to maintain the current regimen that is controlling her asthma because the medications she is taking have evidence of safety in pregnancy. This patient also should have frequent monitoring with regular visits, should be offered a peak flow monitor, and should be counseled regarding the safety of and need for continued asthma medications. The most appropriate management is to continue the current regimen and follow up frequently.

Empirically stepping up asthma therapy in anticipation of worsening asthma symptoms during pregnancy is not warranted. During pregnancy, one third of women have no significant change in their asthma, one third experience worsening of symptoms, and one third experience improvement of symptoms.

Stopping inhaled glucocorticoids and/or montelukast would not be appropriate owing to this patient's likely impairment without controller medications, particularly because these agents are considered safe in pregnancy.