Abstract
Summary: A hypertensive women was treated throughout pregnancy with propranolol 40 mg daily without complication. At delivery the umbilical cord plasma concentration was similar to that in the maternal venous plasma. Milk:plasma ratios were less than 1, although a higher ratio would be predicted. Estimated daily intake of propranolol in breast milk by the infant was about 3 micrograms. There appears to be no reason to advise women receiving propranolol to avoid breast feeding.