Haemorrhagic disease of the newborn

Haemorrhagic Disease of the Newborn (HDN), also known as Vitamin K Deficiency Bleeding (VKDB), is a coagulation disorder in newborns due to inadequate levels of Vitamin K. This condition can lead to unexpected bleeding during the first weeks of life. The severity of HDN can range from mild skin bruising to life-threatening bleeding inside the brain.

Causes

HDN is primarily caused by a deficiency in Vitamin K, which is crucial for the synthesis of clotting factors II, VII, IX, and X in the liver. Newborns are particularly at risk because:

• Vitamin K does not cross the placenta efficiently.
• Breast milk contains low levels of Vitamin K.
• The newborn gut is sterile and cannot synthesize Vitamin K.

Risk Factors

Factors that increase the risk of HDN include:

• Exclusive breastfeeding without Vitamin K supplementation.
• Maternal medications that interfere with Vitamin K metabolism.
• Liver disease in the newborn.
• Prematurity, as it is associated with lower Vitamin K stores.

Classification

HDN is classified based on the timing of onset:

• Early-onset HDN occurs within the first 24 hours of life, often in babies whose mothers took medications that interfere with Vitamin K metabolism.
• Classical HDN presents between day 1 and day 7, characterized by bleeding around the umbilicus, skin, nose, and circumcision sites.
• Late-onset HDN occurs between week 2 and 6 months, often associated with exclusive breastfeeding and poor Vitamin K absorption.

Symptoms

Symptoms of HDN may include:

• Bruising or bleeding from the skin, umbilicus, mucous membranes, or circumcision site.
• Gastrointestinal bleeding.
• Intracranial hemorrhage, which may present as seizures or lethargy.

Diagnosis

Diagnosis of HDN involves:

• Clinical assessment of bleeding and bruising.
• Laboratory tests showing prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT).
• Normal platelet count, as HDN affects clotting factors, not platelet function.
• Confirmation of Vitamin K deficiency through specific blood tests.

Prevention

Prevention of HDN is effectively achieved by administering Vitamin K at birth. The American Academy of Pediatrics recommends a single intramuscular dose of Vitamin K1 for all newborns.

Treatment

Treatment involves the administration of Vitamin K, either orally or intramuscularly, depending on the severity of the condition and the presence of active bleeding. In cases of severe bleeding, additional treatments such as fresh frozen plasma or blood transfusions may be necessary.

Prognosis

With prompt diagnosis and treatment, the prognosis for infants with HDN is generally good. However, intracranial hemorrhage can lead to long-term neurological complications.

Epidemiology

The incidence of HDN varies globally, largely due to differences in Vitamin K prophylaxis practices. Early-onset and classical HDN are now rare in countries where Vitamin K is routinely administered to newborns.