Definition of Hemorrhagic disease of the newborn:

Hemorrhagic disease of the newborn is a bleeding disorder that usually develops shortly after a baby is born.

See also: Hemolytic disease of the newborn

Causes, incidence, and risk factors:

A lack of vitamin K causes hemorrhagic disease of the newborn. Vitamin K is a fat-soluble vitamin that plays an important role in blood clotting.

Babies usually have low levels of vitamin K for a variety of reasons. Vitamin K doesn't move easily across the placenta so a newborn doesn't have much vitamin K stored up at birth. Also, there isn't much vitamin K in breast milk.

Your baby may develop this condition if:

• A preventive vitamin K shot is not given at birth
• You exclusively breastfeed your baby
• You take certain anti-seizure drugs

The condition is grouped into three categories:

• Early onset
• Classic onset (this is typically the type associated with the name, hemorrhagic disease of the newborn)
• Late onset

Early onset hemorrhagic disease of the newborn is very rare. It occurs during the first hours of birth and certainly within 24 hours. The main risk factor is the use of anti-seizure drugs or a blood thinner called coumadin during pregnancy.

Classic onset disease is also rare. It develops in breastfed infants within the first week after birth.

The late onset form is seen in infants older than 2 weeks up to 2 months old. It is particularly common in children of Asian descent.

Risk factors include:

• Alpha1-antitrypsin deficiency
• Biliary atresia
• Breastfeeding
• Celiac disease
• Cystic fibrosis
• Diarrhea
• Hepatitis