In recent years, I have noticed increased hesitancy and even plain refusal from new parents to allow their babies to receive Vitamin K intramuscular injection at birth. This anxiety has initially started in 1992, after a study done by Golding et. al. have shown 2.65-fold increase in leukemia associated with intramuscular Vitamin K injection. The finding has not been replicated by any other subsequent studies. Unfortunately, much public anxiety remains to this day.
Newborn infants that do not receive Vitamin K at birth have increased risk of developing Vitamin K Deficiency Bleeding (VKDB). VKDB can be further categorized into 3 groups based on the time of presentation as early, classical or late.
- Early VKDB occurs in the first 24 hours of life, is severe and usually found in neonates whose mothers have been taking medications that interfere with Vitamin K metabolism.
- Classical VKDB occurs during the first week of life (1 -7 days) and presented with bruising, gastrointestinal, umbilical and circumcision-site bleeding in neonates.
- Late VKDB occurs between two weeks up to 6 months of age in a previously healthy infant. Presentation in late VKDB is usually intracranial bleed. This life-threating condition usually occurs in exclusively breast fed infants without any warning.
Vitamin K is a major player in coagulation pathway as well as co-factor for bone metabolism. Vitamin K1 can be found in green vegetables, such as broccoli and spinach. Vitamin K2 is produced by gut micro-flora. Newborn infants are born with low level of Vitamin K because of its poor placental transfer. Also, since the gut micro flora is not present at birth, it takes time for colonization to occur. Since breast milk contains low level of Vitamin K, infants are predisposed to its low levels, which in return translates to low concentration of coagulation factors and, as a result, places them at increased risk of bleeding.
In different parts of the word, various methods of Vitamin K administration are practiced. In 1961, American Academy of Pediatrics (AAP) recommended single injectable dose of Vitamin K to be given at birth to prevent VKDB of the newborn. The benefits of oral prophylaxis are that it is easy and non-invasive. The main disadvantage is that absorption is not certain and can be affected by vomiting or regurgitation. When multiple doses are prescribed over time, compliance becomes an issue. Intramuscular prophylaxis is more invasive and can be painful. It has been shown that either method would prevent early VKDB. However, several countries have reported a resurgence of late VKDB coincident with policies promoting the use of orally administered prophylaxis, even with multiple-dose regimens. In many studies, neonates that received intramuscular prophylaxis had zero incidence of late VKDB.
Additional studies have been conducted since 1992 and they all have failed to find the relationship between intramuscular Vitamin K administration and childhood cancers. As such, AAP continues to recommend 0.5-1.0 mg of intramuscular Vitamin K prophylaxis .
Thanks, as always!