Hemorrhagic Disease of the Newborn (Vitamin K Deficiency Bleeding)
Hemorrhagic disease of the newborn, now more accurately termed Vitamin K Deficiency Bleeding (VKDB), results from a deficiency of vitamin K-dependent coagulation factors (II, VII, IX, and X).
1. Clinical Classification
| Type | Onset | Clinical Presentation |
|---|---|---|
| Early | First 24 hours | Associated with maternal medications (e.g., anticonvulsants, isoniazid). |
| Classic | Days 2–7 | Common in exclusively breastfed infants; presents as GI/umbilical bleeding. |
| Late | 2–12 weeks | Most severe: Frequently presents with intracranial hemorrhage (ICH). |
2. High-Yield Clinical Pearls
- Why Newborns are Susceptible: Poor placental transfer of vitamin K, low hepatic stores, sterile neonatal gut (lack of vitamin K-producing bacteria), and low content in breast milk.
- Laboratory Profile: Characterized by prolonged Prothrombin Time (PT) and PTT; platelet count and fibrinogen levels are typically normal.
- Prevention: Prophylactic intramuscular vitamin K (1 mg) is universally recommended at birth.
NEET PG Hint: Remember: Late-onset VKDB is significantly more common in exclusively breastfed infants who did not receive birth-dose vitamin K. Intracranial hemorrhage is the most feared and lethal complication of late VKDB. For more high-yield neonatology protocols and free medical questions, visit mymedschool.org.