What is the incidence of adverse events in newborns who did not receive vitamin K (Vitamin K1) at birth?

Incidence of Adverse Events in Babies That Didn't Receive Vitamin K

Newborns who do not receive vitamin K prophylaxis at birth face a significant risk of vitamin K deficiency bleeding (VKDB), with incidence rates ranging from 250-1700 per 100,000 births for early VKDB and 10.5-80 per 100,000 births for late VKDB. 1

Types and Incidence of Vitamin K Deficiency Bleeding

Vitamin K deficiency bleeding in infants occurs in three distinct forms:

1. Early VKDB:

   • Occurs within the first 24 hours after birth
   • Incidence: 250-1700 per 100,000 births without prophylaxis 1
   • Manifestations: Cephalohematoma, intracranial, intrathoracic, or intra-abdominal bleeding

2. Classical VKDB:

   • Occurs within the first week of life
   • Primarily affects the gastrointestinal tract, skin, and umbilical stump

3. Late VKDB:

   • Occurs between 2-12 weeks of age
   • Incidence: 10.5-80 per 100,000 births without prophylaxis 1
   • Most serious form with high mortality and morbidity
   • 50-80% of cases present with intracranial hemorrhage

Clinical Manifestations of VKDB

Infants with vitamin K deficiency may present with:

• Intracranial hemorrhage (occurs in 4 of 7 infants in one case series) 2
• Need for urgent neurosurgical intervention (2 of 7 infants) 2
• Gastrointestinal bleeding
• Skin ecchymoses and bruising
• Mucosal bleeding (including from circumcision sites)
• Large intramuscular hemorrhages
• Vomiting, poor feeding, and lethargy 2

Risk Factors for Severe VKDB

Certain conditions increase the risk of severe bleeding in infants without vitamin K prophylaxis:

• Exclusive breastfeeding (breast milk contains lower vitamin K than formula)
• Cholestasis or impaired intestinal absorption
• Maternal medications that interfere with vitamin K metabolism
• Prematurity
• Birth asphyxia
• Difficult delivery
• Delayed feeding
• Known hepatic disease 3, 4

Laboratory Findings

Infants with VKDB typically show:

• Profound derangement of coagulation parameters 2
• Prolonged prothrombin time (PT) and possibly activated partial thromboplastin time (aPTT) 3
• Normal platelet count
• Rapid correction of coagulation abnormalities after vitamin K administration 2

Prevention Recommendations

The ESPGHAN Committee on Nutrition recommends that all newborn infants should receive vitamin K prophylaxis in one of the following regimens:

• 1 mg vitamin K1 by intramuscular injection at birth (preferred route for efficiency and reliability) 4
• 3 × 2 mg vitamin K1 orally at birth, at 4-6 days, and at 4-6 weeks
• 2 mg vitamin K1 orally at birth, and a weekly dose of 1 mg orally for 3 months 4

Pitfalls and Caveats

• Parental refusal of vitamin K prophylaxis is increasingly common (0-3.2% in US hospitals, up to 14.5% in home births, and up to 31% in birthing centers) 1
• Oral administration is less effective than intramuscular for prevention of late VKDB 5
• The oral route is not appropriate for preterm infants, infants with cholestasis, impaired intestinal absorption, or those too unwell to take oral vitamin K 4
• If an infant vomits or regurgitates within 1 hour of oral administration, the dose should be repeated 4
• Parents who refuse vitamin K are more likely to also refuse immunizations 1

Conclusion

The incidence of adverse events in newborns who don't receive vitamin K prophylaxis is substantial and potentially life-threatening. VKDB can lead to permanent neurological damage or death, with intracranial hemorrhage being the most serious complication. The condition is almost entirely preventable with appropriate vitamin K prophylaxis at birth, making universal administration a critical public health intervention.