Final answer:
When a fetus displays category 3 fetal heart patterns, the nurse's first action should be to change the mother's position to potentially improve fetal circulation, while also preparing for further interventions such as notifying the healthcare provider.
Step-by-step explanation:
The first action the nurse should take when a fetus displays occasional category 3 fetal heart patterns is to change the mother's position. Such heart patterns could indicate fetal distress, which requires immediate nursing interventions and could necessitate an emergency cesarean section if not resolved. The nurse may also administer oxygen to the mother and must notify the healthcare provider promptly.
However, changing the mother's position could alleviate potential compression of the umbilical cord or other compromises to fetal circulation, thereby potentially improving fetal heart rate patterns before more invasive measures are taken. It is important to involve the healthcare provider to assess the situation and determine the appropriate course of action for the safety of both the mother and the baby.