What is the first action the nurse should take if a fetal heartbeat cannot be found at 24 weeks' gestation after it was present at the last visit?

The appropriate action when a fetal heartbeat is not detected at 24 weeks' gestation, especially following a previous detection, is to assess fetal movement. This step is essential as fetal movements can provide crucial information about the health of the fetus. If the mother reports that the baby is or has been moving, it can provide reassurance that the fetus is likely still viable.

Assessing the frequency and quality of fetal movements is a more immediate and non-invasive approach to gather information about the fetal condition. It helps to establish a context for the absence of the heartbeat and may guide further interventions or assessments.

While other actions, such as calling the health care provider or using different equipment, might be necessary later, they do not provide immediate information about fetal status and may delay critical assessment. Therefore, asking about fetal movement is the first step to evaluate the situation effectively.