A nurse is assessing a client who is 1 hr postpartum following a vaginal birth. The nurse notes that the client has excessive vaginal bleeding. Which of the following actions should the nurse take first?

The correct action for the nurse to take first is to massage the client's fundus. This is because excessive vaginal bleeding postpartum could indicate uterine atony, which is a common cause of postpartum hemorrhage. By massaging the fundus, the nurse can help stimulate uterine contractions and reduce bleeding. Administering oxytocin (choice B) may be necessary but massaging the fundus should be done first. Emptying the client's bladder (choice C) can also help, but addressing uterine atony is the priority. Providing oxygen (choice D) is not the immediate action needed for excessive vaginal bleeding.