Acarboxyprothrombin concentration [corrected] after oral prophylactic vitamin K

[Not Available]

Les nouveau-nés sont vulnérables à une hémorragie par carence en vitamine K (HCVK) en raison de réserves prénatales insuffisantes et d’un déficit de vitamine K dans le lait maternel. D’après une analyse systématique des données probantes jusqu’à présent, une injection unique de vitamine K par voie intramusculaire (IM) à la naissance prévient l’HCVK avec efficacité. Selon les données scientifiques actuelles, une dose unique ou des doses répétées de vitamine K par voie orale (PO) sont moins efficaces pour prévenir l’HCVK que la vitamine K IM. La Société canadienne de pédiatrie et le Collège des médecins de famille du Canada recommandent l’administration IM systématique d’une dose unique de 0,5 mg à 1,0 mg de vitamine K à tous les nouveau-nés. L’administration de vitamine K PO (2,0 mg à la naissance, repris à l’âge de deux à quatre semaines et de six à huit semaines) doit être réservée aux nouveau-nés dont les parents refusent l’administration de vitamine K IM. Les dispensateurs de soins devraient expliquer aux parents que leur nouveau-né court un plus grand risque d’HCVK si cette posologie est privilégiée. Les données probantes actuelles sont insuffisantes pour recommander l’administration systématique de vitamine K par voie intraveineuse aux nouveau-nés prématurés en soins intensifs.

Mots-clés HDNB; Newborn; Prophylaxis; Vitamin K; VKDB

Position Statement: Guidelines for vitamin K prophylaxis in newborns: A joint statement of the Canadian Paediatric Society and the College of Family Physicians of Canada

Newborns are at risk for vitamin K deficiency bleeding (VKDB) caused by inadequate prenatal storage and deficiency of vitamin K in breast milk. Systematic review of evidence to date suggests that a single intramuscular (IM) injection of vitamin K at birth effectively prevents VKDB. Current scientific data suggest that single or repeated doses of oral (PO) vitamin K are less effective than IM vitamin K in preventing VKDB. The Canadian Paediatric Society and the College of Family Physicians of Canada recommend routine IM administration of a single dose of vitamin K at 0.5 mg to 1.0 mg to all newborns. Administering PO vitamin K (2.0 mg at birth, repeated at 2 to 4 and 6 to 8 weeks of age) should be confined to newborns whose parents decline IM vitamin K. Health care providers should clarify with parents that newborns are at increased risk of VKDB if such a regimen is chosen. Current evidence is insufficient to recommend routine intravenous vitamin K administration to preterm infants undergoing intensive care.Keywords HDNB; Newborn; Prophylaxis; Vitamin K; VKDB.

Guidelines for vitamin K prophylaxis in newborns

Newborns are at risk for vitamin K deficiency bleeding (VKDB) caused by inadequate prenatal storage and deficiency of vitamin K in breast milk. Systematic review of evidence to date suggests that a single intramuscular (IM) injection of vitamin K at birth effectively prevents VKDB. Current scientific data suggest that single or repeated doses of oral (PO) vitamin K are less effective than IM vitamin K in preventing VKDB. The Canadian Paediatric Society and the College of Family Physicians of Canada recommend routine IM administration of a single dose vitamin K at 0.5 mg to 1.0 mg to all newborns. Administering PO vitamin K (2.0 mg at birth, repeated at 2 to 4 and 6 to 8 weeks of age), should be confined to newborns whose parents decline IM vitamin K. Health care providers should clarify with parents that newborns are at increased risk of VKDB if such a regimen is chosen. Current evidence is insufficient to recommend routine intravenous vitamin K administration to preterm infants undergoing intensive care.

Dietary reference values for vitamin K

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derives dietary reference values (DRVs) for vitamin K. In this Opinion, the Panel considers vitamin K to comprise both phylloquinone and menaquinones. The Panel considers that none of the biomarkers of vitamin K intake or status is suitable by itself to derive DRVs for vitamin K. Several health outcomes possibly associated with vitamin K intake were also considered but data could not be used to establish DRVs. The Panel considers that average requirements and population reference intakes for vitamin K cannot be derived for adults, infants and children, and therefore sets adequate intakes (AIs). The Panel considers that available evidence on occurrence, absorption, function and content in the body or organs of menaquinones is insufficient, and, therefore, sets AIs for phylloquinone only. Having assessed additional evidence available since 1993 in particular related to biomarkers, intake data and the factorial approach, which all are associated with considerable uncertainties, the Panel maintains the reference value proposed by the Scientific Committee for Food (SCF) in 1993. An AI of 1 μg phylloquinone/kg body weight per day is set for all age and sex population groups. Considering the respective reference body weights, AIs for phylloquinone are set at 70 μg/day for all adults including pregnant and lactating women, at 10 μg/day for infants aged 7-11 months, and between 12 μg/day for children aged 1-3 years and 65 μg/day for children aged 15-17 years.

Prevention of Vitamin K Deficiency Bleeding in Newborn Infants: A Position Paper by the ESPGHAN Committee on Nutrition

Vitamin K deficiency bleeding (VKDB) due to physiologically low vitamin K plasma concentrations is a serious risk for newborn and young infants and can be largely prevented by adequate vitamin K supplementation. The aim of this position paper is to define the condition, describe the prevalence, discuss current prophylaxis practices and outcomes, and to provide recommendations for the prevention of VKDB in healthy term newborns and infants. All newborn infants should receive vitamin K prophylaxis and the date, dose, and mode of administration should be documented. Parental refusal of vitamin K prophylaxis after adequate information is provided should be recorded especially because of the risk of late VKDB. Healthy newborn infants should either receive 1 mg of vitamin K1 by intramuscular injection at birth; or 3 × 2 mg vitamin K1 orally at birth, at 4 to 6 days and at 4 to 6 weeks; or 2 mg vitamin K1 orally at birth, and a weekly dose of 1 mg orally for 3 months. Intramuscular application is the preferred route for efficiency and reliability of administration. The success of an oral policy depends on compliance with the protocol and this may vary between populations and healthcare settings. If the infant vomits or regurgitates the formulation within 1 hour of administration, repeating the oral dose may be appropriate. The oral route is not appropriate for preterm infants and for newborns who have cholestasis or impaired intestinal absorption or are too unwell to take oral vitamin K1, or those whose mothers have taken medications that interfere with vitamin K metabolism. Parents who receive prenatal education about the importance of vitamin K prophylaxis may be more likely to comply with local procedures.

Vitamin K in neonates: how to administer, when and to whom

Vitamin K-dependent factors are lower in neonates than in adults, and these anomalies are more prevalent in preterm neonates and in breast-fed infants. Vitamin K deficiency can account for vitamin K deficiency bleeding (VKDB) which occurs in 3 forms--early, classic and late. Vitamin K should be administered to all neonates at birth or immediately afterwards. However, the protocols for administration (route of administration, dosage, number of doses) remain a subject of discussion. Oral administration of a single dose of vitamin K protects against classical and early VKDB, but is less effective than intramuscular (IM) prophylaxis for the prevention of late VKDB. Although an increased risk of solid tumour, associated vitamin K administration, can be definitively excluded, a low potential risk of lymphoblastic leukaemia in childhood can not be ruled out. For formula-fed neonates without risk of haemorrhage, a 2 mg oral dose of vitamin K at birth, followed by a second 2 mg oral dose between day 2 and 7, is probably sufficient to prevent VKDB. For infants who are exclusively or nearly exclusively breast-fed, weekly oral administration of 2mg (or 25 microg/day) vitamin K after the initial 2 oral doses is justified at completion of breast-feeding. For neonates at high risk of haemorrhage (premature, neonatal disease, birth asphyxia, difficult delivery, any illness which will delay feeding, known hepatic disease, maternal drugs inhibiting vitamin K activity), the first dose must be administered by the IM or slow intravenous route. Doses should be repeated, particularly in premature infants, by a route of administration decided for each dose according to the clinical state of the infant. For infants of mothers treated with drugs inhibiting vitamin K activity, antenatal maternal prophylaxis (10 to 20 mg/day orally for 15 to 30 days before delivery) prevents early VKDB. After neonatal prophylaxis, as for infants at high risk of haemorrhage, doses need to be repeated at a rate and route of administration decided for each dose, according to the clotting factor profile specific for each infant.

Administration of Vitamin K to newborns: implications and recommendations

The review by Drs. Brousson and Klein (see pages 307 to 315 of this issue) identifies controversies surrounding the administration of vitamin K to babies shortly after birth. Controlled studies comparing the effect of oral and intramuscular administration are unlikely to be conducted because of the large number of subjects needed. The evidence presented in the review should dispel concerns that intramuscular administration may be associated with childhood cancer. Oral administration of a single dose of vitamin K soon after is associated with significant biochemical vitamin K deficiency by 1 month of age, but the relation of biochemical abnormality to clinical manifestations of late hemorrhagic disease of the newborn is less clear. Epidemiologic studies indicate a small, but significant, increase in the incidence rate of hemorrhagic disease after oral administration of vitamin K (1.0 to 6.4 incidents per 1000 000 infants), compared with the incidence rate after intramuscular administration (0.25 incidents per 100 000 infants). Although repeated oral doses of vitamin K may be and effective alternative regimen, there is no approved oral vitamin K formulation, there are concerns about patient compliance, and there has been limited investigation of such regimen. Therefore, intramuscular administration of a single dose of 1.0 mg of vitamin K shortly after birth is recommended.

Haemorrhagic disease in newborn and older infants: a study in hospitalized children in Kelantan, Malaysia

This is a retrospective study of the epidemiology, clinical features, laboratory findings, treatment and outcome of haemorrhagic disease in 42 Kelantanese infants who were admitted to Hospital Universiti Sains Malaysia during a 2-year period (1987-1988). Classical haemorrhagic disease of the newborn was the commonest presentation (48%), followed by early onset (29%) and late onset (24%) disease. Home deliveries accounted for 81% of the affected infants. Most of these babies were not given vitamin K at birth in contrast to those delivered in hospitals. All except one infant were breastfed. The six commonest presenting clinical features were pallor, jaundice, umbilical cord bleeding, tense fontanelle, convulsions and hepatomegaly. All the infants had prolonged prothrombin and partial thromboplastin times which were corrected by administration of vitamin K. Subdural haemorrhage was the commonest form of intracranial haemorrhage, followed by subarachnoid haemorrhage. The overall case fatality rate was 14%. The results of this study once again emphasize the value of vitamin K prophylaxis in the newborn.

Effects of oral and intramuscular vitamin K prophylaxis on vitamin K1, PIVKA-II, and clotting factors in breast fed infants

A randomised clinical trial was conducted to establish the effects of oral and intramuscular administration of vitamin K at birth on plasma concentrations of vitamin K1, proteins induced by vitamin K absence (PIVKA-II), and clotting factors. Two groups of about 165 healthy breast fed infants who received at random 1 mg vitamin K1 orally or intramuscularly after birth were studied at 2 weeks and 1 and 3 months of age. Although vitamin K1 concentrations were statistically significantly higher in the intramuscular group, blood coagulability, activities of factors VII and X and PIVKA-II concentrations did not reveal any difference between the two groups. At 2 weeks of age vitamin K1 concentrations were raised compared with reported unsupplemented concentrations and no PIVKA-II was detectable. At 3 months vitamin K1 concentrations were back at unsupplemented values and PIVKA-II was detectable in 11.5% of infants. Therefore, a repeated oral prophylaxis will be necessary to completely prevent (biochemical) vitamin K deficiency beyond the age of 1 month.

Vitamin K to neonates. Peroral versus intramuscular administration

In a randomized study of 300 infants, the effect of 1 mg of peroral vitamin K given at birth was compared to the same dose given as an intramuscular injection. The combined activity of coagulation factor II + VII + X taken after 48 and before 72 hours after delivery served as the primary endpoint. Prothrombin (antigen) and PIVKA II (acarboxyprothrombin) were also measured. All infants were observed for events of bleeding until discharge from the hospital, normally on the fifth day. No significant differences between the groups in any of the biochemical markers were observed. The 95% confidence limits of the differences were very narrow for all factors. No cases of bleeding were observed. We conclude that administration of 1 mg peroral vitamin K is as efficient as intramuscular administration of the same dose in the prevention of classical hemorrhagic disease of the newborn.

Vitamin K in infancy

Vitamin K has regained paediatric interest due to a recurrence of bleeding caused by deficiency of the vitamin in newborns and young infants. Increasing awareness of these clinical problems, the development of new methods for the detection of vitamin K deficiency and the direct measurement of vitamin K in tissues have stimulated research. Much new data obtained from these studies has proved helpful to the understanding of vitamin K deficiency in infancy. For example low concentrations of vitamin K have been found in fetal and neonatal livers. The implications of these findings with respect to manifest vitamin K deficiency and to new methods for detection of subclinical vitamin K deficiency are discussed. Breast-feeding is a major risk factor for classical haemorrhagic disease of the newborn and for late onset bleeding due to vitamin K deficiency in young infants. The interdependencies between breast-feeding and vitamin K deficiency are discussed on the basis of new data obtained from direct measurement of vitamin K in maternal milk. The review further focuses on pathophysiological concepts of bleeding due to vitamin K deficiency in infancy and current concepts of vitamin K prophylaxis.