Vitamin K Deficieny, Bleeding in the Newborn
Vaginal Bleeding in the Newborn,
Vit K deficiency,
Home birth is associated with
many clinical problems, including vitamin K deficiency.
- IM 0.5 to 1.0 mg vitamin
is a routine part of neonatal care in the United States and helps to prevent
hemorrhagic disease of the newborn.
- Vitamin K is required to
activate the procoagulant
factors 2, 7, 9, and 10 as well as proteins C and S, all of which are
synthesized in the liver.
All of the following factors
contribute to vitamin K deficiency, low levels of vitamin K-dependent factors,
and when severe enough, clinical hemorrhagic disease of the newborn:
- Neonatal hepatic immaturity
impairs the synthesis of these factors and limits the effectiveness of vitamin
transfer of vitamin K also may be a contributing factor.
- Delayed colonization of the gut by
bacteria (which become an endogenous source of vitamin K) is another
factor that occurs with delayed feeding, breastfeeding, vomiting,
severe diarrhea, and the use of antibiotics (including those that are present in
- Classic vitamin K deficiency
presents in the first week of life (except first 24 hrs) with
- epistaxis, purpura
- large cephalohematomas, intracranial hemorrhage
- melena, GI, GU bleeding
- bleeding from the umbilical stump, injection sites, and after circumcision.
- Bleeding occurs most commonly from the
second to seventh days of life in healthy,
solely breastfed, and often term
infants who have not received prophylactic vitamin K.
occurs rarely in formula-fed infants
because of the supplemental vitamin K in those products.
prophylactic vitamin K is not administered, the frequency of clinical bleeding
- much more common than the early or late forms of the disease.
- Early vitamin K deficiency
- severe bleeding within the first 24 hours
- linked to maternal use of medications (most often anticonvulsants (phenobarb,
phenytoin), coumadin, also
that interfere with vitamin K stores or function.
Late vitamin K deficiency (2 to 8 weeks of age) is linked to a compromised
supply of vitamin K or malabsorption, as seen with
- exclusive breast feeding without vit K ppx
- cystic fibrosis of the pancreas
- biliary atresia
- celiac disease
- may cause: CNS and other life-threatening bleeding
- In vitamin K deficiency:
- prolonged PT, PTT are prolonged
- decreased vitamin K-dependent factors
(factors II, VII, IX, and X and proteins C and S) a
- normal non-vitamin K- dependent factors (factors V, VIII, and fibrinogen)
- platelet counts are normal.
- Immunoassays, however, will reveal normal
antigenic levels of the vitamin K-dependent factors.
Bleeding in the neonate has many other
- If thrombocytopenia accompanies a prolonged PT and PTT,
disseminated intravascular coagulation
- Factor VIII and IX deficiency
hemophilia will cause prolongation of the PTT but not the PT. Both of
these disorders are X-linked recessive and, thus, rarely occur in females.
Liver disease can be the most
confusing aspect of the differential diagnosis. It prolongs the PT and PTT and
decreases vitamin K-dependent factors, but factor V and fibrinogen also are
decreased. Hepatic function is abnormal in contrast to the normal-for-age
function seen in vitamin K deficiency.
- Disorders such as
and rectal fissures can result in gastrointestinal bleeding in the
absence of coagulopathy. However, rectal fissures do not cause melena, and
necrotizing enterocolitis rarely occurs in healthy term infants.
- Prophylactic vitamin K is used widely to prevent hemorrhagic disease of the
- There had been some debate over the necessity of prophylaxis because of
the relative rarity of clinically evident hemorrhage and questions of toxicity.
However, discontinuation of
prophylaxis resulted in a recurrence of hemorrhagic disease of the newborn.
Current consensus is that prophylaxis
should be continued (1 mg Vit K IM)
- The initial dose of vitamin K1 usually is
administered in a parenteral
dose of 1 mg or an oral dose of 2 mg.
- Subsequent doses have been
recommended for infants who are breastfed or who have a malabsorptive disorder.
- In underdeveloped countries, an alternative is administration of oral vitamin K,
which is considerably less expensive to breastfed infants.
Treatment of clinical hemorrhagic
disease of the newborn necessitates frequent doses of subcutaneous or
intravenous vitamin K1 (NOT IM); intramuscular administration should be avoided.
May also give FFP.
- Improvement will occur within 24
hours with vitamin K1 alone, but plasma should be used to treat infants who
are experiencing serious bleeding.
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