What is vitamin K deficiency bleeding (VKDB) in an infant with a bleeding disorder?

What is Vitamin K Deficiency Bleeding (VKDB) in Infants with Bleeding Disorders?

VKDB is a serious, preventable bleeding disorder in infants caused by inadequate vitamin K-dependent coagulation factors (II, VII, IX, X), presenting with skin bleeding, mucosal hemorrhage, large intramuscular hemorrhages, generalized ecchymoses, or life-threatening intracranial hemorrhage—and it can occur even in infants with underlying bleeding disorders, making prophylaxis essential for all newborns. 1, 2

Definition and Pathophysiology

VKDB occurs when newborns have insufficient vitamin K to synthesize adequate levels of vitamin K-dependent clotting factors. 3 The condition is diagnosed by:

• Prolonged PT (prothrombin time) and possibly aPTT for age 1
• Normal fibrinogen level and platelet count 4
• Rapid correction of PT within 2-4 hours after vitamin K administration, which is diagnostic 5, 6
• Measurement of PIVKA-II (proteins induced by vitamin K absence) can confirm diagnosis in patients who already received treatment 1

Clinical Presentations by Age

VKDB is classified into three types based on timing: 3, 4

Early VKDB (within 24 hours)

• Rare presentation
• Often associated with maternal medications interfering with vitamin K metabolism 5

Classic VKDB (days 1-7)

• Most common timeframe for presentation
• Bleeding from circumcision, umbilical stump 1, 2
• Gastrointestinal bleeding 7

Late VKDB (2 weeks to 6 months)

• Most dangerous form with up to 50% experiencing intracranial hemorrhage 7
• Strongly associated with exclusive breastfeeding and cholestasis 3, 8
• Can be life-threatening 3

Specific Clinical Manifestations

The bleeding presentations include: 1, 2, 7

• Bleeding in the skin or from mucosal surfaces
• Bleeding from circumcision sites
• Generalized ecchymoses (widespread bruising)
• Large intramuscular hemorrhages
• Intracranial hemorrhage (ICH)—the most devastating complication
• Gastrointestinal bleeding
• Umbilical stump bleeding

Risk Factors for VKDB

High-risk infants include: 5, 3, 8

• Exclusively breastfed infants (breast milk contains low vitamin K levels)
• Infants whose mothers took anticonvulsants, anticoagulants, or antituberculosis drugs
• Infants with cholestasis or malabsorption disorders
• Infants with cystic fibrosis
• Infants with alpha-1-antitrypsin deficiency 1, 5
• Infants who did not receive vitamin K prophylaxis at birth

Critical Distinction: VKDB vs. Other Bleeding Disorders

Important clinical caveat: The presence of a bleeding disorder does not rule out abuse as the etiology for bruising or bleeding, and conversely, a history of trauma does not exclude VKDB or other medical conditions. 1 VKDB must be distinguished from:

• Immune thrombocytopenia (ITP)—requires platelet count screening 1
• Hemophilia and other factor deficiencies 1
• Platelet function disorders 1
• Von Willebrand disease 1

Prevention: The Gold Standard

All newborns should receive vitamin K prophylaxis: 5, 6, 8

Intramuscular Route (Preferred)

• Single IM dose of 0.5-1.0 mg vitamin K1 within one hour of birth 2, 6
• Most effective route for preventing all forms of VKDB 6, 8
• Prevents early, classic, AND late VKDB 6

Oral Route (Alternative if IM refused)

• 2 mg at birth, 2 mg at 4-6 days, and 2 mg at 4-6 weeks 5, 6, 8
• OR 2 mg at birth, then weekly 1 mg doses for 3 months 5, 6, 8
• Less effective than IM administration 8
• Success depends on parental compliance 8

Special Populations

• Preterm infants on parenteral nutrition: 10 μg/kg/day 5, 6
• Oral route NOT appropriate for: preterm infants, cholestasis, malabsorption, critically ill infants, or maternal medication interference 8

Warning Signs Requiring Immediate Evaluation

Recognize these predisposing conditions early: 4

• Prolonged jaundice beyond expected timeframe
• Failure to thrive
• Any "warning bleeds" (minor bleeding episodes)
• Easy bruising in exclusively breastfed infant without prophylaxis

Monitoring Considerations

• PIVKA-II is the preferred biomarker for at-risk patients when available 5, 6
• Classical coagulation tests (PT, aPTT) can be used but are not specific 5
• Routine monitoring of vitamin K concentrations is not recommended 5

Common Pitfalls to Avoid

1. Do not assume oral prophylaxis is equivalent to IM—it requires multiple doses and perfect compliance 8
2. Do not overlook exclusively breastfed infants—they remain at highest risk for late VKDB 3, 8
3. Do not dismiss parental refusal lightly—document thoroughly and provide education about life-threatening complications 8, 7, 9
4. Do not use oral route in high-risk populations (cholestasis, malabsorption, preterm) 8