A full-term exclusively breastfed male infant, born at home and given no injections at birth, presents at day 4 with oozing from the umbilical stump and blood in the stool. Prothrombin time is markedly prolonged while platelet count is normal. The primary reason this infant developed bleeding is:
- A Human breast milk contains very little vitamin K and the neonatal gut is initially sterile ✓
- B Breast milk contains a factor that antagonizes thrombin generation
- C Neonatal platelets have defective ADP release
- D Maternal IgG antibodies against factor VIII crossed the placenta
Correct answer: A. Human breast milk contains very little vitamin K and the neonatal gut is initially sterile
Explanation
Classic hemorrhagic disease of the newborn results from three converging factors: very low vitamin K content of human milk, a sterile gut at birth with no bacterial synthesis of vitamin K, and immature hepatic stores. Without gamma-carboxylation, factors II, VII, IX, and X are functionally inactive, prolonging PT with normal platelets. Routine intramuscular vitamin K at birth prevents this condition. Factor VIII inhibitors cause hemophilia A-like bleeding unrelated to feeding mode, and platelet function defects would produce petechiae.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.