Use of beta blockers during pregnancy may cause low blood sugar, breathing problems, a slow heart rate and low blood pressure in the newborn. However, if the mother’s condition warrants the use of beta blockers during pregnancy, they can be used under her physician’s guidance. Patients should inform their physicians if they are pregnant or trying to become pregnant before beginning any medication.

When breast feeding, some beta blockers will pass from mother to infant and others may reduce the flow of breast milk. This may cause a slow heartbeat, low blood pressure or breathing difficulties in the nursing infant. Therefore, an alternative feeding method may be recommended when beta blockers are being used. Parents should weigh the benefits and risks with their physicians.