A nurse is caring for a client who is 12 hr postpartum. Which of the following findings should alert the nurse to the possibility of a postpartum complication?

A. Fundus palpable at the umbilicus: A firm fundus at the level of the umbilicus is an expected finding at 12 hours postpartum and indicates effective uterine contraction. It does not suggest a complication. B. Urine output of 3,000 mL in 12 hr: Increased urine output in the first 12–24 hours postpartum is common as the body eliminates excess fluid accumulated during pregnancy. This is a normal physiologic response and not a complication. C. Orthostatic hypotension: A sudden drop in blood pressure when moving from lying to standing may indicate hypovolemia, blood loss, or other postpartum complications. This finding requires prompt assessment to prevent falls and identify potential underlying issues such as hemorrhage. D. Heart rate 110/min: Mild tachycardia can occur postpartum due to pain, anxiety, or mild physiologic changes. While it should be monitored, it is less immediately concerning than orthostatic hypotension, which poses greater risk to maternal stability.