Drug treatment exposes both the pregnant woman and her unborn child to adverse effects.

In treating a pregnant woman, it is better to choose a drug with a favourable harm-benefit balance for both the mother and the unborn child.

During pregnancy, women asthma sufferers are at risk of increased severity of the attacks, which requires modifications to be made to their treatment. Aggravations occur particularly between the 24th and 36th weeks of pregnancy and in women already suffering from severe asthma.

Poorly managed asthma during pregnancy increases the risks for the mother: vomiting, arterial hypertension, pre-eclampsia, vaginal bleeding, complications and the need to induce labour. It also exposes the fetus to risks including perinatal death, intra-uterine growth restriction, low birth weight and neonatal hypoxia.

In practice, pregnancy should not affect asthma treatment as long as the reference drugs are prescribed, particularly as first-line treatments: salbutamol, an inhaled short-acting beta-2 agonist, inhaled budesonide, a corticosteroid, inhaled salmeterol, a long-acting beta-2 agonist, and oral prednisone, a corticosteroid.

Some drugs should be ruled out, including montelukast and omalizumab, due to their uncertain efficacy as asthma treatments and their harms during pregnancy, which have not been clearly established.

©Prescrire 1 February 2014

"Asthma in pregnancy. Drugs of choice and drugs to avoid" Prescrire Int 2014; 23 (146): 50-51. (Pdf, subscribers only).