When assessing a multigravida on the first postpartum day, the nurse finds a moderate amount of lochia rubra, with the uterus firm and three fingerbreadths above the umbilicus. What action should the nurse implement first?

Choice B reason: Reviewing the hemoglobin to determine hemorrhage is an important action, but not the first one. The nurse should first identify and correct the cause of bleeding, such as bladder distension or uterine atony, before checking for blood loss and anemia. Choice C reason: Massaging the uterus to decrease atony is not indicated in this case, because the uterus is already firm. Massaging a firm uterus can cause overstimulation and pain. Choice D reason: Increasing intravenous infusion is not the first action, because it may worsen bleeding by increasing blood pressure and diluting clotting factors. The nurse should first assess and manage bleeding before administering fluids or blood products as prescribed.