Asthma in pregnant patients: pathophysiology and management

Epidemiological studies have shown that approximately 1-4% of pregnancies are complicated by bronchial asthma, but these percentages are likely to be substantially underestimated because, in many cases, the condition will be undiagnosed, just as in the nonpregnant population. Undertreatment of pregnant asthmatics especially owing to unfounded fears of adverse pharmacological effects on the developing foetus, remains the major problem. Several studies have demonstrated that severe, uncontrolled asthma may produce serious maternal and foetal complications; consequently pregnant females with severe asthma must be considered at a particularly high risk. In this review we present recent data regarding the physiological respiratory changes in pregnancy, the effect of asthma on the course and outcome of pregnancy, the effect of the pregnancy on the course of the illness and options for effective and appropriate medical management with emphasis for preventive and pharmacological aspects. Since bronchial asthma is a chronic condition with acute exacerbations, a continuing management is necessary to control symptoms, prevent acute obstructions and reduce the degree of airway inflammation. An optimized management of asthma in pregnant females is supported by four integral components: 1)objective assessment of maternal lung function and foetal wellbeing 2) avoidance or control of environmental precipitating factors; 3) pharmacological therapy; and 4) patient education. As regards to pharmacological therapy, we must state that patients with poorly controlled asthma must be evaluated for the use of the same drugs and protocols utilized for nonpregnant females in order to avoid the risk of a potentially life-threatening evolution of the disease. Inhalation therapy is generally better than systemic treatment; in fact this route of drug delivery strongly reduces the risk of systemic side effects and the likelihood of foetal penetration.