Why is a vitamin K (phylloquinone) injection important at birth?

Importance of Vitamin K Injection at Birth

Vitamin K injection at birth is critically important because it prevents potentially life-threatening Vitamin K Deficiency Bleeding (VKDB) in newborns, which can lead to severe intracranial hemorrhage, permanent neurological damage, or death. 1, 2

Understanding Vitamin K Deficiency in Newborns

• Newborns are physiologically vitamin K deficient due to poor placental transfer, low vitamin K content in breast milk, and immature gut flora that limits absorption 2
• Without prophylaxis, infants are at risk for three types of VKDB:
  • Early VKDB (within 24 hours of birth)
  • Classic VKDB (within first week)
  • Late VKDB (between 2 weeks and 6 months) 2
• Late VKDB is particularly dangerous as it often presents with intracranial hemorrhage, which can be fatal or cause permanent neurological damage 3

Risk Factors for Vitamin K Deficiency Bleeding

• Exclusively breastfed infants (breast milk contains low levels of vitamin K) 4
• Infants whose mothers took medications that interfere with vitamin K metabolism (anticonvulsants, anticoagulants, antituberculosis drugs) 4
• Infants with underlying conditions such as cystic fibrosis, alpha-1-antitrypsin deficiency, or cholestasis 4
• Preterm infants 1

Evidence Supporting Vitamin K Prophylaxis

• The European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) strongly recommends vitamin K prophylaxis for all newborns 1
• The American Academy of Pediatrics recommends a single intramuscular dose of 0.5 to 1.0 mg vitamin K1 for newborns within one hour of birth 5
• Studies show that intramuscular vitamin K administration is more effective than oral administration in preventing all forms of VKDB, particularly late VKDB 6
• Documented cases of life-threatening intracranial hemorrhages have occurred in infants whose parents refused vitamin K prophylaxis 3

Recommended Administration Methods

• Intramuscular route (preferred): 1 mg of vitamin K1 at birth - most reliable method with highest efficacy 1
• Oral alternatives (if parents refuse IM injection):
  • 3 × 2 mg vitamin K1 orally at birth, at 4-6 days, and at 4-6 weeks; OR
  • 2 mg vitamin K1 orally at birth, followed by weekly doses of 1 mg for 3 months 1
• The success of oral administration depends heavily on compliance with the protocol, which may vary between populations and healthcare settings 1

Clinical Implications of Vitamin K Refusal

• Increasing parental refusal of vitamin K prophylaxis has led to a rise in preventable cases of VKDB 3
• In one study over an 8-month period, seven infants with confirmed vitamin K deficiency were identified; four had intracranial hemorrhage, and two required urgent neurosurgical intervention 3
• All these cases could have been prevented with proper vitamin K administration at birth 3

Monitoring for Vitamin K Deficiency

• Classical coagulation tests (PT, PTT) can be used for indirect evaluation of vitamin K status in low-risk infants 4
• Undercarboxylated Serum Vitamin K-Dependent Proteins (PIVKA-II) are more specific biomarkers for subclinical vitamin K deficiency in at-risk groups 4

Special Considerations

• Oral administration is not appropriate for preterm infants, infants with cholestasis, impaired intestinal absorption, or those too unwell to take oral vitamin K1 1
• If an infant vomits or regurgitates oral vitamin K within 1 hour of administration, the dose should be repeated 1
• Preterm infants on parenteral nutrition should receive 10 μg/kg/day of vitamin K 4

The evidence clearly demonstrates that vitamin K prophylaxis at birth is a simple, safe, and highly effective intervention that prevents a potentially devastating bleeding disorder in newborns.