Epidemiology
Etiology
- Exclusive breastfeeding: low vitamin K levels in breast milk (most important in late-onset VKDB)
- Vitamin K deficiency in the mother (e.g., because of anticonvulsant therapy; most important in early-onset VKDB; maternal malnutrition)
- Underdeveloped intestinal flora (which produces vitamin K), e.g., due to premature birth
- Long-term antibiotic treatment in newborns
Classification
- Early onset: within 24 hours after birth; intracranial bleeding common
- Classic: within 1 week after birth; intracranial bleeding rare
- Late onset: between 2–8 months after birth; intracranial bleeding common
Pathophysiology
Clinical features
- Classically presents on day 2-7 of life
- Easy bruising
- Umbilical, mucosal & gastrointestinal bleeding
- Intracranial hemorrhage
Diagnostics
Treatment
In the US, all newborns receive intramuscular vitamin K (0.5–1 mg) at birth.