Maternal beta-blocker dose and risk of small-for gestational-age in women with heart disease.

We found a five-fold increased risk of delivering a small-for-gestational-age infant in women with heart disease treated with a high dose of beta-blocker, and a two-fold increased risk among those treated with a low dose, showing an apparent dose-response relation. Close monitoring of fetal growth is warranted among women with heart disease treated with beta-blockers. As drug therapy in pregnancy concerns both mother and fetus, an optimum balance for both should be the goal.