Late hemorrhagic disease of the newborn as a cause of intracerebral bleeding.

We report a case of a 4-week-old female who presented with late hemorrhagic disease of the newborn (HDN). The newborn was previously healthy, and she received 1 mg of intramuscular vitamin K at birth. She was exclusively breast-fed. At 4 weeks she began bleeding at the umbilicus and 4 days after she suffered an intracranial hemorrhage. Coagulation studies showed a deficiency of vitamin K-dependent coagulation factors, and the normalization of all clotting studies after administration of vitamin K confirmed the diagnosis of HDN. Our conclusions are that physicians must be alert to mild bleeding in newborns and that prophylaxis with 1 mg of intramuscular vitamin K at birth may be insufficient to prevent late HDN.