Maternal Newborn: Newborn Vitamin K Prophylaxis

Vitamin K deficiency bleeding (VKDB) is unexpected bleeding caused by too little vitamin K activity. Newborns begin life with limited vitamin K because placental transfer is poor, intestinal bacteria that contribute to vitamin K production are not yet established, and human milk contains little vitamin K. Formula feeding does not remove the need for prophylaxis. Vitamin K is required in the liver to produce active clotting factors II, VII, IX, and X. When vitamin K is insufficient, clot formation is impaired even though an infant may initially feed, breathe, and appear well. Bleeding may be visible at the umbilicus, gastrointestinal tract, mucosa, or a puncture site, but it may also occur internally, including in the brain. Routine phytonadione prophylaxis supplies vitamin K before deficiency causes bleeding. A single intramuscular (IM) dose is the preferred Canadian approach because it prevents VKDB more reliably than oral administration. Prophylaxis does not explain or treat every cause of newborn bleeding. Thrombocytopenia, trauma, infection, liver disease, or a congenital coagulation disorder may require a different investigation and treatment plan. A documented prophylactic dose therefore never...