Final answer:
The nurse should first encourage the client to void to prevent a full bladder from displacing the uterus. Subsequent actions include assessing lochia, aiding with breastfeeding, and documenting the observations.
Step-by-step explanation:
Following the delivery of a newborn, it is most important for nurses to take action to ensure the health and well-being of the mother as she begins the recovery process. When the nurse observes that the fundus is approximately 1 cm above the umbilicus 12 hours after delivery, this suggests that the uterus is contracting as it should; however, the position of the fundus can also be influenced by bladder distention. Therefore, the most crucial action a nurse should take is to encourage the client to void to ensure that a full bladder is not displacing the uterus and interfering with the process of involution, which can lead to excessive bleeding or infection.
The nurse should follow up with other actions as well, including assessing the amount and character of the lochia, bringing the infant to the client for breastfeeding (which helps with uterine contractions and bonding), and documenting all findings and actions taken in the client's medical record.