Heparin-like inhibitor, not vitamin-K deficiency, in the newborn

Vitamin K deficiency bleeding (VKDB) in early infancy

Vitamin K deficiency bleeding (VKDB) is a rare and potentially life-threatening bleeding disorder of early infancy. Vitamin K stores are low at birth; thereafter breast-fed infants are at risk because of low concentrations in human milk. Classical VKDB occurs in the first week of life, is related to delayed or inadequate feeding and is readily prevented by small doses of vitamin K at birth. Late VKDB peaks at 3-8 weeks, typically presents with intracranial haemorrhage often due to undiagnosed cholestasis with resultant malabsorption of vitamin K. Diagnosis can be difficult but PIVKA-II measurements can provide confirmation even several days post-treatment. Without vitamin K prophylaxis, the incidence of late VKDB in Europe is 4-7 cases per 10(5) births; it is higher in SE Asia where in rural, low-income areas some 0.1% of affected infants may suffer intracranial bleeding. Late VKDB is largely preventable with parenteral vitamin K providing the best protection. The efficacy of oral prophylaxis is related to the dose and frequency of administration. Most multi-dose oral regimens provide protection for all except a small reservoir of infants with undetected hepatobiliary disease. Targeted surveillance of high-risk groups (e.g. biliary atresia) offers a novel approach to assess efficacy of prophylaxis.

Prevention of vitamin K deficiency bleeding in newborns

Newborn babies are born vitamin K deficient; however, the deficiency is not sufficiently severe to cause a vitamin K deficiency coagulopathy and haemorrhagic disease of the newborn (HDN). Severe vitamin K deficiency can develop quickly in breast-fed newborns and can result in the appearance of classic HDN during the first week of life or late HDN during the first 2 months of life. Both forms of the disease can be severe, causing brain damage and death. Classic and late HDN are prevented by the intramuscular administration of vitamin K at birth. Oral prophylaxis prevents classic HDN but is ineffective in preventing late HDN. Despite proven effectiveness of intramuscular vitamin K prophylaxis there have been concerns about the need for, and safety of, this therapy. This review provides evidence that there is need for intramuscular vitamin K prophylaxis for all babies in order to eradicate haemorrhagic disease of the newborn and concludes that there is no evidence that this therapy is harmful.

Vitamin K coagulation status in surgical newborns and the risk of bleeding

The vitamin K coagulation status in surgical newborns, who may be at increased risk of developing hypocoagulability and hemorrhage, has not previously been studied. Therefore, we measured the combined activity of the plasma vitamin K-dependent coagulation factors (Thrombotest), total prothrombin, PIVKA II, plasma vitamin K1, fibrinogen, D-Dimer, and platelets in 49 newborns admitted to a neonatal surgical intensive care unit. All infants had significant pathology, and treatment involved surgery in all but two. Twenty-three infants (47%) underwent surgery on two or more occasions. Intravenous or oral antibiotics were used in all patients and many received more than one course. All infants had vitamin K1 prophylaxis at birth. At day 0 (date of birth), the mean Thrombotest and total prothrombin levels were 51% (range, 20% to 100%) and 40% (range, 24% to 59%), respectively. Coagulation activity decreased on day 1 (P > .1) and was followed by a graduate increase in clotting activity, reaching normal adult levels (> 60%) at day 5 for Thrombotest and day 24 for total prothrombin. Only three infants had a Thrombotest less than 20%. PIVKA II was detected in 20 cases (41%). However, levels were within normal limits (< 0.9%) in 17 of these, and between 1.0 and 4.8% in the remaining three infants. There was no relationship between elevated PIVKA levels and coagulation activity in these patients. Plasma vitamin K1 was very high, particularly in the first days of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Vitamin K-dependent coagulation parameters during the first six days of life: incidence of PIVKA II in newborns

The vitamin K-dependent carboxylation of the prothrombin precursor PIVKA II (protein induced by vitamin K absence analogous to Factor II) is essential for the synthesis of prothrombin. The noncarboxylated precursor is found in peripheral blood in the presence of vitamin K deficiency. In this study prothrombin time, Factor II and Factor VII activity, and PIVKA II were investigated in 57 newborns without vitamin K prophylaxis in order to assess their vitamin K status. Two-dimensional immunoelectrophoresis demonstrated the presence of PIVKA II in 21% of the newborns, predominantly on the second day. The PIVKA-II positive group showed significantly lower prothrombin times than the PIVKA II-negative group. An oral dose of 3 mg vitamin K (Konakion) was administered to 35 healthy newborns in a second group with the first feeding. On the second day of life, these infants showed significantly higher vitamin K-dependent laboratory parameters than the group not given vitamin K; only 9% of the treated infants were positive for PIVKA II.

The prolongation of the thrombotest clotting time in newborns

As judged from thrombotest dilution curves clotting inhibiting material was present in 67% of human umbilical cord plasma samples of healthy full term infants (n = 40). The correlation coefficient (r-value) between the thrombotest clotting times and the prothrombin levels was -0.46. Using sensitive enzyme immuno assays for fibrin degradation products (FbDP) and fibrinogen degradation products (FgDP), we found that no degradation products could be demonstrated in the non-inhibited group whereas small amounts of these products were present in the inhibited group. These small amounts were undetectable using conventional assays. The most striking finding was the presence of fibrin and fibrinogen degradation products. The prolongation of the thrombotest clotting time could be imitated by adding fibrinogen fragment X to umbilical cord plasma in which no clotting inhibiting material was present in the thrombotest dilution curve. We conclude that the thrombotest clotting is of limited value in the assessment of the vitamin K-dependent coagulation factors in umbilical cord plasma. As utmost care was taken to avoid proteolytic breakdown in vitro, our findings most likely reflect an enhanced fibrino(geno)lytic activity in umbilical cord plasma in vivo.

Vitamin K in the newborn: influence of nutritional factors on acarboxy-prothrombin detectability and factor II and VII clotting activity

The incidence of acarboxy-prothrombin and the clotting activity of factors II and VII were evaluated on the fifth day of life in 183 healthy newborns, who had received no vitamin K prophylaxis. Acarboxy-prothrombin was detected in 93/183 newborns. All acarboxy-prothrombin-negative babies had factors II and VII clotting activities above 25% whereas a great variability was observed in acarboxy-prothrombin-positive babies: 21/93 had factor II and 14/93 had factor VII activities below 25%. Seventy-two of the acarboxy-prothrombin-positive babies had normal factor II and VII clotting times on the fifth day of life. These babies must be suspected to have had vitamin K deficiency on one of the first 4 days, as acarboxy-prothrombin has a 50% disappearance rate of 50 h. Acarboxy-prothrombin was mainly observed in breast-fed infants (84/122) and only rarely detectable in infants receiving supplementary (7/44) or exclusive formula feeding (2/17). The type of milk feeding however might be less important for the babies' vitamin K supply than the actual milk intake. All acarboxy-prothrombin-positive babies had received small amounts of milk on the first 4 days of life. In those with low factor II and VII clotting activities the milk intake was low throughout the first 4 days of life, whereas babies with acarboxy-prothrombin and and normal clotting activities had increased their milk intake to more than 100 ml on the third and fourth day of life. Recommendations for vitamin K prophylaxis in newborns should be given with regard to the feeding on the first days of life.

The placental transport of [3H]vitamin K1 in rats

In this paper we describe the placental transport of [3H]vitamin K1 in pregnant rats during the first 24 h after the oral administration of the vitamin. Vitamin K1 in the fetal livers ranged from 0.13% (3 h) to 2% (24 h) of the values found in the corresponding maternal livers. In spite of the low placental transfer of vitamin K, we found no accumulation of coagulation factor precursors in the fetal rat liver microsomes as could be expected in vitamin K deficiency. Moreover, we could not demonstrate any difference between adult and fetal rat liver microsomes with regard to the sensitivity for warfarin. From these results we conclude that a substantial placental barrier exists for the transport of pharmacological amounts of vitamin K1 but that under physiological conditions sufficient vitamin K1 appears to be present in the fetal liver to ensure a full carboxylation reaction. The vitamin K-dependent carboxylase activity rate of adult and fetal rat liver microsomes was comparable, indicating that the newborn rat has an adequate carboxylating system.

Vitamin K deficiency in the newborn infant: prevalence and perinatal risk factors

The prevalence of vitamin K deficiency in newborn infants and the influence of perinatal risk factors were studied prospectively in 934 infants. A noncarboxylated prothrombin assay to detect proteins induced in vitamin K absence (PIVKA-II) was used to determine the presence of vitamin K deficiency; of 934 cord blood samples assayed, 2.9% were positive for PIVKA-II (0.015 to 0.15 U/ml). All infants found to have detectable PIVKA-II were born at term. The number of infants positive for PIVKA-II was greater in the group small for gestational age (7.4%) than in those appropriate (2.7%) or large (3.1%) for gestational age. Nine categories of perinatal risk groups were defined: however, the majority of infants who were PIVKA-II positive (63%) were normal. All infants received prophylactic vitamin K, and no infant with PIVKA-II in the cord sample subsequently had clinical bleeding. In two patients the rate of 50% disappearance of PIVKA-II after vitamin K administration approximated 70 hours. Two PIVKA-II positive patients with active bleeding or disseminated intravascular coagulation had an accelerated disappearance of 20 to 40 hours. The long disappearance time of PIVKA-II in a steady state may allow detection of vitamin K deficiency despite administration of vitamin K. The majority of cases of neonatal vitamin K deficiency occurred in normal newborn infants. Therefore, all infants should receive prophylactic vitamin K at birth.

Vitamin K and Thrombotest values in full term infants

The vitamin K dependent clotting factors were measured by the 'Thrombotest' on the second day of life in 72 healthy full term babies, half of whom had received vitamin K at birth. Forty eight of these were breast fed, and those not given vitamin K had significantly lower Thrombotest values than those who had received vitamin K. By contrast, administration of vitamin K did not affect the Thrombotest values in bottle fed babies, the values in treated and untreated babies being the same and of the same order as the level in those breast fed babies treated with vitamin K. Serial study of 18 normal breast fed babies tested at day 0 and day 2 showed a pronounced drop in the Thrombotest values in this period, which was prevented by one intramuscular dose of 1 mg vitamin K at birth. Although none of the neonates in this study showed haemorrhagic disease, nine of the 24 untreated breast fed infants had Thrombotest values below 10% on day 2, at which level bleeding has been reported.

Serum vitamin K1 concentration and vitamin K-dependent clotting factor activity in maternal and fetal cord blood

The serum concentration of phylloquinone (vitamin K1) was measured in 34 healthy mothers and in the arterial cord blood of their newborn infants. In addition, the activities of factor II and of factors VII plus X were determined simultaneously in 16 paired maternal and fetal bloods. The serum vitamin K1 concentration was similar to that of control subjects in 27 mothers: 9.03 +/- 4.9 micrograms/L (mean and SD), with a simultaneous concentration of 10.4 +/- 5.3 micrograms/L in cord blood. Six mothers exhibited high serum vitamin K1 concentrations from 40 to 240 micrograms/L (median, 82) and the concentration in cord blood ranged from 25 to 115 micrograms/L (median, 71). One mother had a normal concentration of vitamin K1: 9 micrograms/L while no vitamin K1 was detectable in the serum of her infant. The activity of factor II and factors VII plus X was 7% and 7%, respectively, in this infant and 100% in the mother. All other mothers showed normal factor II and factors VII plus X activity, while the median activity was 47% (28%-56%) for factor II and 65% (35%-100%) for factors VII plus X in cord blood. These data suggest that vitamin K1 can cross the placental barrier but not in every case. Therefore the systematic administration of vitamin K1 to the newborn infant seems to be required to prevent the occurrence of the hemorrhagic disease.

Vitamin K1 in the newborn

By a sensitive high-performance liquid chromatography method it was possible to measure vitamin K1 concentrations in mothers and their newborn children, even at a level of 0.5 nmol/l. All neonates were born after an uncomplicated and full-term pregnancy. The vitamin K1 concentration in neonates proved to be about half the value of their mothers, which is consistent with earlier studies of vitamin K1 dependent clotting factors. One may assume the existence of a partial placental barrier to vitamin K1. Venous, arterial and mixed cord blood did not differ significantly, so puncturing the vena umbilicalis is sufficient to measure vitamin K1 concentrations in cord blood.

Effect of vitamin K administration on acarboxy prothrombin (PIVKA-II) levels in newborns

PIVKA-II (protein induced by vitamin K absence or antagonist-II) was measured in two groups of newborns, one group being given 5 mg vitamin K at birth and the other untreated. The untreated group had a significantly higher proportion of PIVKA-II positive babies at 3 and 5 days of age than did the treated group. When vitamin K was administered to newborn babies whose normotest levels were less than 30%, it was found that the higher the pre-treatment PIVKA-II levels the greater the response to vitamin K, as monitored by the normotest. Thus PIVKA-II levels might be more useful than a coagulation test, since the low activity of vitamin K dependent coagulation factors sometimes reflects not vitamin K deficiency but impaired production of these factors because of immaturity. The findings support the view that vitamin K given prophylactically at birth will help to prevent neonatal bleeding.

Delayed presentation of haemorrhagic disease of the newborn

Six infants with delayed presentation of haemorrhagic disease of the newborn are described. All were full-term infants who had no underlying disease, but did not receive prophylactic doses of vitamin K at birth and were breast-fed. Two infants have been left with permanent handicaps as a result of this uncommon, but preventable, disorder.

Factor II (prothrombin) levels in cord blood: correlation of coagulant activity with immunoreactive protein

Hypoprothrombinemia occurs in newborn infants, but it is unclear whether this is the result of reduced production of Factor II precursor or a vitamin K deficient state. In this study, 76 cord blood specimens were analyzed for functional factor coagulant activity and levels of Factor II antigen as determined by electroimmunoassay. In 40 normal term infants, CA = 30% +/- 1.6 (mean +/- SEM) and Ag = 44% +/- 2.3; in 17 normal preterm infants CA = 30% +/- 1.0 and Ag = 31% +/- 4.2; and in 50 normal adults CA = 83 +/- 3 and Ag = 91 +/- 4. In the term infants the average ratio of CA:Ag was 0.90 and in the preterm infants 0.96, both values being similar to those in adults and suggesting underproduction of the precursor form. In 19 term infants who experienced complications of pregnancy and/or delivery, the ratio was 0.76; seven of these ratios were less than 0.70 (range 0.40 to 0.69). These data show that hypoprothrombinemia is common in infant cord blood and is most marked in preterm infants. In the normal infants the CA:Ag ratios were normal, suggesting that the hypoprothrombinemia is the result of reduced production of the protein and not of vitamin K deficiency. However, term infants with complications of labor and delivery had reduced CA:Ag ratios that were suggestive of vitamin K deficiency.

Post-natal development of factor IX

Post-natal development of clotting activity and of antigen level of Factor IX was evaluated in 111 healthy, breastfed, newborn infants, aged 1-30 days. Of these, 80 had received at birth 2 mg of vitamin K1 orally. Factor IX clotting activity was determined by one-stage assay and antigen level by electroimmunoassay. On the 1st day both antigen level and clotting activity were low and the ratio was 1.01. There was a significant postnatal increase of the two activities of Factor IX during the first three days of life; thereafter both remained constant. No statistical difference inFactor IX activity was found with oral administration of vitamin K1 after the birth. During the first month of life both clotting activity and antigen level of Factor IX were low as compared to adult values. There was no correlation with age. The Factor IX protein of newborns did not show molecular heterogeneity by crossed-immunoelectrophoresis.

Coagulation studies on umbilical arterial and venous blood from normal newborn babies

Coagulation studies using conventional methods and chromogenic substrates were performed on umbilical arterial and venous blood from 33 newborns after delivery. In the arterial samples, thrombin time (TT) was significantly prolonged and the activities of factors I, II, V and VII, as well as the inhibitors heparin, antithrombin III and antiplasmin, were significantly decreased. This could probably be explained by a mild form of disseminated intravascular coagulation (DIC) occurring in the baby during delivery.

Etiopathology and classification of acquired coagulation disorders in the newborn infant

In the newborn period low vitamin K dependent coagulation factors are frequently found in connection with normal global tests. To investigate this peculiar coagulation status studies were performed in 54 newborns who were divided into three groups according to their clinical course and the existence of bleeding. The results are compared to coagulation tests used for the diagnosis of disseminated intravascular coagulation (DIC). An early sign of an increased turnover of coagulation factors is a difference in the fibrinogen concentration determined by an immunological technique and a coagulation test which is sensible to fibrin(ogen)-degradation-products (FDP'S). At this stage factor II, V and VII levels are still within the normal range suggesting an increased production. In a more severe disturbance of the clotting system the increased turnover is no longer compensated by an increased production, and platelets and later on factor II and VII levels are lowered. At this early stage of DIC the vitamin K dependent factors are correlated to the factors I and V. Finally factors I and V drop as well. This stage in most infants is accompanied by the clinical symptom of bleeding. The clotting tests results are well correlated to the severity of the disease.