Asthma, asthma medications and their effects on maternal/fetal outcomes during pregnancy

Maternal asthma may increase the risk of adverse fetal and maternal outcomes such as low birth weight, perinatal mortality, preterm birth, preeclampsia, hypertensive disorders, maternal mortality, uterine hemorrhage, and gestational diabetes. Controlling asthma during pregnancy with appropriate medications leads to improved intrauterine growth of the fetus and fewer adverse perinatal outcomes. Prospective population or birth cohort studies have shown that the medications used to treat asthma, such as bronchodilators (short-acting β2-agonists) and controller medications (inhaled corticosteroids, cromones, theophylline, leukotriene inhibitors), have no or minimal effects on fetal growth, and perinatal complications are reduced when maternal asthma is adequately controlled. However, taking oral corticosteroids during pregnancy may confer increased risk of lower birth weight and congenital malformations. Therefore, managing pregnant asthmatics requires a careful benefit–risk analysis, and when indicated, the benefits of a medication that may have increased risks can dictate its use in severe uncontrolled asthma.

► Asthma control is important during pregnancy and if suboptimal, has a negative effect on mother and baby outcomes.
► Inhaled steroids and bronchodilators, the mainstay of asthma treatment, are relatively safe for use during pregnancy.
► In contrast, oral corticosteroids when used in the first trimester of pregnancy, increase the risk of lower birth weight and congenital malformations.
► Biologicals such as antibodies, interrupt the inflammatory cascade but do not cross the placenta until later in pregnancy after fetal organ development has occurred.