<prompt> Which of the following is not true about late onset Hemorrhagic disease of newborn HDN?Begins between 2-7 days of lifeIntracranial Hemorrhage is commonBiliary atresia can predisposeWarfarin therapy is associated  <response>: Ans. a Begins between 2-7 days of life Ref Care of Newborn by Maherbansingh 6,th336; Oskis Pediatrics - Pg. 468As classified by Hathaway, hemorrhagic disease of the newborn HDN can occur in early, classic, and late forms.Early HDN presents in first 24 hrs of life generally with catstrophic bleeding. Classic vitamin K deficiency bleeding of the newborn is the most common type of hemorrhagic disease in newborns and classic HDN occurs between 2 and 7 days of life and usually presents as Gl bleeding. Vitamin K 0.5 to 1 mg given IMIy at birth prevents classic hemorrhagic disease of the newborn, which occurs at 2-7 days of age. Late onset HDN occurs l-3months after birth and is asso with a high incidence CNS hemorrhage and motality.HDN Hemorrhagic disease of newbornFeaturesEarly HDNClassical HDNLate HDNOnset 24 hoursUp to 1-7 days2-16 weeksPresentationConcealed bleedingBleeding from umbilical cord stump, nose, GIT and during surgery e.g., circumcisionBleeding more common from sites like intracranial; vessels, skin, mucous membrane, GIT, etcEtiologyIn utero vitamin K deficiency Most common due to physiologic deficiency of vitamin K in newborns fed with breast milk. Vitamin K content of human milk 15 mcgL is half that of the cow milk. Predisposing factors are:- Chronic diarrhea,- Malabsorption,- Hepatic cholestasis e.g. bililary atresia- Long-term broad-spectrum antibiotics and- Mucovisidosis.- Warfarin therapy- Rare in formula-fed babies and those who have received inj. vitamin K at birth.- Mortality is 20 in late HDN. 