Pregnancy is a dynamic process that consists of profound physiological changes mediated by hormonal, mechanical, and circulatory pathways. Understanding of changes in physiology is essential for distinguishing abnormal and normal signs and symptoms in a pregnant patient. These physiological changes also have important pharmacotherapeutic considerations for a pregnant patient. Although there are limited data to guide decisions regarding medications and diagnostic procedures in pregnancy, a careful review of risks should be balanced with review of risk of withholding a medication or procedure. Interventional pulmonary procedures can be safely performed in pregnant women while keeping in mind the maternal anatomic and physiologic changes. Furthermore, management of a maternal cardiopulmonary arrest requires important modifications in patient positioning and intravenous access to ensure adequate efficacy of chest compressions, circulation, and airway management. This review will provide an overview of maternal physiologic changes with a focus on cardiopulmonary physiology, pharmacotherapeutic considerations, diagnostic and interventional pulmonary procedures during pregnancy, and cardiopulmonary resuscitation in pregnancy.