What is the main purpose of the non-stress test (NST)?

The primary purpose of the non-stress test (NST) is to assess fetal heart rate patterns in response to fetal movements. During the test, external fetal monitoring is used to observe the baby's heart rate and how it changes with movements, which indicates the well-being of the fetus. A reactive NST, characterized by an increase in fetal heart rate with movements, is a reassuring sign that the fetus is receiving adequate oxygen and is not in distress.

In contrast, evaluating maternal blood pressure pertains to the overall health of the mother rather than the specific assessment of fetal well-being. Monitoring uterine contractions is related to labor evaluation but does not provide direct information about fetal heart response. Checking for placental abruption is a specific medical concern and does not align with the fundamental purpose of the NST, which is focused on direct fetal assessment rather than potential complications in pregnancy. Thus, the non-stress test is an important tool in obstetric care for ensuring the health of the fetus by closely monitoring its heart rate patterns.