Vitamin K deficiency bleeding (VKDB) of the newborn is a bleeding disorder in babies. It most often develops in the first days and weeks of life.

Hemorrhagic disease of the newborn (HDN)

A lack of vitamin K may cause severe bleeding in newborn babies. Vitamin K plays an important role in blood clotting.

Babies often have a low level of vitamin K for a variety of reasons. Vitamin K does not move easily across the placenta from the mother to the baby. As a result, a newborn does not have much vitamin K stored up at birth. Also, the bacteria that help make vitamin K are not yet present in a newborn's gastrointestinal tract. Finally, there is not much vitamin K in mother's milk.

Your baby may develop this condition if:

• A preventive vitamin K shot is not given at birth (if vitamin K is given by mouth instead of as a shot, it must be given more than once, and it does not appear to be as effective as the shot).
• The mother takes certain anti-seizure or blood-thinning drugs.

The condition is grouped into three categories:

• Immediate-onset VKDB is very rare. It occurs within the first 48 hours after birth and is usually a result of anti-seizure medicines or some other medicines, including a blood thinner called warfarin (Coumadin), taken by mothers during pregnancy.
• Early-onset (formerly called “classic-onset”) disease is also rare. It occurs between 1 to 14 days after birth. It is usually seen in breastfed infants who did not receive a vitamin K shot.
• Late-onset VKDB is seen in infants between 2 weeks and 6 months old. It is also more likely to happen in those who did not receive a vitamin K shot.

Anyone of any age with the following problems involving the gastrointestinal system is also at risk to develop this disorder:

• Alpha1-antitrypsin deficiency
• Biliary atresia or other cholestatic liver disease
• Celiac disease
• Cystic fibrosis or other causes of pancreatic insufficiency
• Diarrhea (prolonged)
• Hepatitis
• Inflammatory bowel disease

Vitamin K deficiency causes bleeding. The most common areas of bleeding include:

• At the site of circumcision
• Belly button area
• Gastrointestinal tract (resulting in blood in the baby's bowel movements)
• Mucous membranes (such as the lining of the nose and mouth)
• Places where there has been a needle stick
• The brain

There may also be:

• Blood in the urine
• Bruising
• Seizures (convulsions) or abnormal behavior due to bleeding inside the skull

Blood clotting tests will be done.

The diagnosis can be confirmed if a vitamin K shot stops the bleeding and blood clotting time (PT or prothrombin time) quickly becomes normal (within 6 to 24 hours). (If the deficiency is not severe, the PT may not be abnormal.)

Vitamin K is given if bleeding occurs. Babies with severe bleeding may need plasma or blood transfusions.

The outlook tends to be worse for babies with late-onset hemorrhagic disease than other forms. There is a higher rate of bleeding inside the skull (intracranial hemorrhage) associated with the late-onset condition.

Complications may include:

• Bleeding inside the skull (intracranial hemorrhage), with possible brain damage
• Death

Contact your health care provider if your baby has:

• Any unexplained bleeding
• Seizures
• Abdominal behavior

Get emergency medical care right away if the symptoms are severe.

The early onset form of the disease may be prevented by giving vitamin K shots to pregnant women who take anti-seizure medicines. To prevent the classic and late-onset forms, the American Academy of Pediatrics recommends giving every baby a shot of vitamin K immediately after birth. Because of this practice, vitamin K deficiency is now rare in the United States except for those babies who do not receive the vitamin K shot.

Greenbaum LA. Vitamin K deficiency. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 66.

Hand I, Noble L, Abrams SA. Vitamin K and the newborn infant. Pediatrics. 2022;149(3):e2021056036. PMID: 35190810 pubmed.ncbi.nlm.nih.gov/35190810/.

Samji N, Chan A, Bhatt MD. Bleeding and clotting disorders in pediatrics. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 148.