Final answer:
The priority action for a nurse, when a fetal heart rate is measured at 100 beats/minute, is to turn the woman on her left side, followed by assessing the maternal heart rate and notifying the primary care provider. This situation might indicate fetal distress and require immediate intervention.
Step-by-step explanation:
A nurse assesses fetal heart tones at 100 beats/minute; the priority action by the nurse should be to turn the woman on her left side. This position can improve uteroplacental blood flow, potentially increasing the oxygen delivery to the fetus. The nurse should then assess the maternal heart rate to ensure that the fetal heart rate is not confused with the mother's. If the fetal heart rate remains low, this could be a sign of fetal distress, and therefore, the nurse must notify the primary care provider immediately. Provision of 100% oxygen could be considered if indicated, but it is not the first line of action. According to the Apgar score system, heart rate and respiration are the most critical criteria to assess the well-being of the newborn. A heart rate of fewer than 100 beats per minute at birth is concerning and warrants prompt evaluation and intervention. Sustained decreases in fetal heart rate during labor can be a sign of fetal distress and might necessitate an emergency birth.1