What is the most likely diagnosis for a newborn with delayed separation of the umbilical cord, bleeding from the umbilical stump, prolonged Prothrombin Time (PT) and Partial Thromboplastin Time (PTT), and a normal platelet count?

Vitamin K Deficiency

The most likely diagnosis is Vitamin K deficiency (Option C), which classically presents with umbilical stump bleeding, prolonged PT and PTT, and normal platelet count in newborns. 1

Why Vitamin K Deficiency is the Answer

Vitamin K deficiency affects multiple coagulation factors simultaneously (factors II, VII, IX, and X), which explains why both PT and PTT are prolonged. 1 This is the hallmark laboratory pattern that distinguishes it from other bleeding disorders. 1

Classic Clinical Presentation

• Umbilical stump bleeding is a pathognomonic presentation of vitamin K deficiency bleeding (VKDB) in newborns. 1
• The combination of prolonged PT with normal fibrinogen and platelet count is almost diagnostic of VKDB in a bleeding infant. 1
• Other typical presentations include bleeding from circumcision, generalized ecchymoses, and intramuscular hemorrhages. 1

Diagnostic Confirmation

• The diagnosis is confirmed by rapid correction of PT/PTT within 30 minutes to 2-4 hours after vitamin K administration. 1
• Measurement of proteins induced by vitamin K absence (PIVKA-II) can provide additional confirmation if the infant has already received vitamin K or fresh-frozen plasma. 1

Why the Other Options Are Incorrect

Factor XIII Deficiency (Option A) - EXCLUDED

• Factor XIII deficiency presents with normal PT, PTT, and platelet count—not prolonged PT and PTT as in this case. 2, 3
• While delayed umbilical cord separation (beyond 2-3 weeks) with bleeding is classic for Factor XIII deficiency, the prolonged PT and PTT in this patient rule it out. 2, 4
• Factor XIII activity is not detected by routine coagulation panels because these tests only measure clot formation time, not clot stability. 2

Von Willebrand Disease (Option B) - EXCLUDED

• Von Willebrand disease would show prolonged bleeding time due to impaired platelet adhesion, and the bleeding time is normal in this case. 1
• Severe cases might show prolonged PTT and abnormal platelet function testing, which are not present here. 2, 3
• Normal platelet count and function effectively exclude von Willebrand disease. 3

Thrombocytopenia (Option D) - EXCLUDED

• The platelet count is explicitly stated as normal, which completely rules out thrombocytopenia. 2, 3

Immediate Management

Administer 1 mg vitamin K intramuscularly or intravenously immediately while awaiting confirmatory laboratory correction. 1

• For life-threatening bleeding, consider fresh-frozen plasma for immediate factor replacement. 1
• Expected response: shortened prothrombin time within 2-4 hours. 1
• If coagulopathy does not correct after vitamin K administration, pursue further evaluation for inherited bleeding disorders. 1

Critical Risk Factor to Assess

Determine if vitamin K prophylaxis was administered at birth, as compliance varies and some institutions/states do not mandate it. 1

• Breast-feeding is a primary risk factor for VKDB, as breast milk contains insufficient vitamin K. 1
• The absence of vitamin K prophylaxis at birth is the most significant risk factor for VKDB. 1