Vitamin K deficiency bleeding

Vitamin K deficiency bleeding (VKDB) is a condition characterized by spontaneous bleeding in infants due to low levels of vitamin K-dependent coagulation factors. Because vitamin K has poor placental transfer, is present in low concentrations in breast milk, and the neonatal gut is initially sterile, all newborns have low vitamin K stores at birth. VKDB is rare in industrialized countries due to the standard prophylactic vitamin K injection given at birth. The condition is categorized as early-onset (within 24 hours after birth), classic (within 1 week), or late-onset (1 week to 6 months). Common bleeding sites include the gastrointestinal tract, umbilical stump, or nose, though life-threatening intracranial or subgaleal hemorrhages can occur. Treatment focuses on managing active bleeding with vitamin K administration and, in severe cases, blood products like four-factor prothrombin complex concentrate to restore homeostasis.

• Without prophylaxis: affects 0.25–1.7% of newborns ^[1]

Epidemiological data refers to the US, unless otherwise specified.

The underlying cause is always a deficiency of vitamin K, which can be due to various factors:

• Vitamin K deficiency in the mother
  • Because of therapy with anticonvulsants, antibiotics, antituberculosis agents, or warfarin: most important in early-onset VKDB
  • Maternal malnutrition
• Poor placental passage of vitamin K
• Underdeveloped intestinal flora (which produces vitamin K), e.g., due to premature birth
• Exclusive breastfeeding: low vitamin K levels in breast milk (most important in late-onset VKDB)
• Chronic diarrhea of the newborn
• Cholestatic diseases (e.g., biliary atresia)
• Long-term antibiotic treatment in newborns

References:^[2]

• Early onset: within 24 hours after birth
• Classic: : within 1 week after birth
• Late onset: between 1 week and 6 months after birth; highest risk of intracranial bleeding

• Common bleeding sites
  • Cutaneous: generalized ecchymoses and easy bruising (notably the face and neck)
  • Gastrointestinal: hematochezia, melena, or hematemesis
  • Umbilical: persistent oozing or frank bleeding from the umbilical cord stump
  • Mucosal: epistaxis and bleeding from the gums
  • Urogenital: hematuria
  • Deep tissue: large intramuscular hemorrhages
• Life-threatening manifestations
  • Intracranial hemorrhage (ICH): the most serious complication, often presenting with a bulging fontanelle, irritability, seizures, or altered consciousness
  • Signs of hypovolemia: pale skin, tachycardia, and poor perfusion due to acute blood loss

Coagulation studies:

• ↑ Prothrombin time (PT)
• Normal or ↑ activated partial thromboplastin time (PTT)
• Normal bleeding time
• ↓ Factors II, VII, IX, and X

• Nonmajor bleeding: PO or IM vitamin K
• Major bleeding (with hemodynamic instability)
  • IV vitamin K (slow infusion)
  • Four-factor prothrombin complex concentrate (4F PCC) for rapid factor replacement
  • If 4F PCC is unavailable, fresh frozen plasma (FFP)

In the US, all newborns receive intramuscular vitamin K (0.5–1 mg) at birth.