Vitamin K Deficiency Bleeding in Infancy

Abstract

Vitamin K is essential for the synthesis of few coagulation factors. Infants can easily develop vitamin K deficiency owing to poor placental transfer, low vitamin K content in breast milk, and poor intestinal absorption due to immature gut flora and malabsorption. Vitamin K deficiency bleeding (VKDB) in infancy is classified according to the time of presentation: early (within 24 h), classic (within 1 week after birth), and late (between 2 week and 6 months of age). VKDB in infancy, particularly late-onset VKDB, can be life-threatening. Therefore, all infants, including newborn infants, should receive vitamin K prophylaxis. Exclusive breastfeeding and cholestasis are closely associated with this deficiency and result in late-onset VKDB. Intramuscular prophylactic injections reduce the incidence of early-onset, classic, and late-onset VKDB. However, the prophylaxis strategy has recently been inclined toward oral administration because it is easier, safer, and cheaper to administer than intramuscular injection. Several epidemiological studies have shown that vitamin K oral administration is effective in the prevention of VKDB in infancy; however, the success of oral prophylaxis depends on the protocol regimen and parent compliance. Further national surveillance and studies are warranted to reveal the optimal prophylaxis regimen in term and preterm infants.

An Infant with Bruising and Lethargy

“…The mortality rate in infants affected by late-onset VKDB is 20%. 6 Intracranial hemorrhage impacts 50% of infants with this form of VKDB with lingering neurologic deficits that are dependent on the location of the hemorrhage, severity of the bleeding, and the amount of time before the bleeding has been controlled. The severity of the sequelae of VKDB warrants swift assessment and treatment even before conclusive laboratory values have been obtained.…”

“…Evaluation of vitamin K-dependent factors (II, VII, IX, and X) and their response to treatment with vitamin K 1 will confirm the diagnosis. 6 A magnetic resonance imaging or computed tomography scan should also be completed to evaluate the presence or absence of intracranial hemorrhage. 7 Rapid treatment should not be delayed by outstanding laboratory results if late-onset VKDB in a bleeding newborn is suspected.…”

The challenge to define the optimal prophylactic regimen for vitamin K deficiency bleeding in infants

“…given until 3 months of age. 24,40 In 2014, the Canadian Paediatric Society reaffirmed postnatal administration of a single intramuscular vitamin K dose of 0.5 mg for birthweight ≤1500 g or 1 mg for ≥1500 g to all healthy newborns within the first 6 hours. If parents refused parenteral route, three oral doses of 2 mg vitamin K were recommended, the first at birth, the second at 2-4 weeks and the third at 6-8 weeks.…”

“…Nonetheless, the fifth nationwide surveillance conducted from 1999 to 2004 showed 71 late‐onset VKDB, 21 of which were idiopathic cases. Therefore, in 2011 new guidelines were proposed using oral vitamin K prophylaxis with 2 mg phytomenadione at birth, followed by weekly oral doses of 1 mg given until 3 months of age 24,40 …”

A Haploid Genetic Screening Method for Proteins Influencing Mammalian Nonsense-Mediated mRNA Decay Activity

“…Any host gene exons residing 5' of the gene-trap integration site are spliced to the splice acceptor site, producing a non-functional eGFP fusion protein that is likely unstable. The gene-trapping method has been used extensively to generate null alleles in mice (34,35). We produced VSV-G pseudotyped genetrap retroviral particles and infected ~100 million HAP1 cells.…”