Summary
Terminology. Replace the term “Hemorrhagic Disease of the Newborn” (HDN) by “Vitamin K Deficiency
Bleeding” (VKDB), as neonatal bleeding is often not due to VK-deficiency and VKDB
may occur after the 4-week neonatal period. Definition. VKDB is bleeding due to inadequate activity of VK-dependent coagulation factors (II,
VII, IX, X), correctable by VK replacement. Diagnosis. In a bleeding infant a prolonged PT together with a normal fibrinogen level and platelet
count is almost diagnostic of VKDB; rapid correction of the PT and/or cessation of
bleeding after VK administration are confirmative. Warning signs. The incidence of intracranial VKDB can be reduced by early recognition of the signs
of predisposing conditions (prolonged jaundice, failure to thrive) and by prompt investigation
of “warning bleeds”. Classification. VKDB can be classified by age of onset into early (<24 h), classical (days 1-7) and
late (>1 week <6 months), and by etiology into idiopathic and secondary. In secondary
VKDB, in addition to breast feeding, other predisposing factors are apparent, such
as poor in-take or absorption of VK. VK-Prophylaxis: Benefits. Oral and intramuscular VK (one dose of 1 mg) protect equally well against classical
VKDB but intramuscular VK is more effective in preventing late VKDB. The efficacy
of oral prophylaxis is increased with a triple rather than single dose and by using
doses of 2 mg vitamin K rather than 1 mg. Protection from oral doses repeated daily
or weekly may be as high as from i.m. VK. VK-Prophylaxis: Risks. VK is involved in carboxylation of both the coagulation proteins and a variety of
other proteins. Because of potential risks associated with extremely high levels of
VK and the possibility of injection injury, intramuscular VK has been questioned as
the routine prophylaxis of choice. Protection against bleeding should be achievable
with lower peak VK levels by using repeated (daily or weekly) small oral doses rather
than by using one i.m. dose. Breast feeding mothers taking coumarins. Breast feeding should not be denied. Supervision by pediatrician is prudent. Weekly
oral supplement of 1 mg VK to the infant and occasional monitoring of PT are advisable.
Conclusion. VKDB as defined is a rare but serious bleeding disorder (high incidence of intracranial
bleeding) which can be prevented by either one i.m. or multiple oral VK doses.