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

The primary purpose of the non-stress test (NST) is to monitor fetal heart rate patterns. This test is typically conducted in the third trimester of pregnancy to assess the well-being of the fetus. During the NST, the fetal heart rate is measured for a specific period while the mother remains at rest. The test looks for accelerations in the fetal heart rate in response to fetal movements, which indicates that the fetus is receiving adequate oxygen and is neurologically intact. A reactive NST, which shows these heart rate accelerations, generally suggests a healthy fetal condition. It can help identify potential issues like fetal distress or compromised blood flow, allowing for timely intervention if necessary.

The other options focus on aspects that are not the primary intention of the NST. Checking maternal blood pressure is more related to assessing the mother's health rather than the fetus's condition. Assessing maternal nutrition is important for overall pregnancy health, but it does not relate to the immediate monitoring of fetal well-being like the NST does. Evaluating uterine contractions is typically performed through other tests, such as a contraction stress test or during labor assessments, rather than during a non-stress test. Thus, the focus of the NST remains exclusively on the fetal heart rate patterns to determine the fetal status.