Which procedure evaluates the effect of fetal movement on fetal heart activity?

• A. Sonography.
• B. Contraction test.
• C. Biophysical profile.
• D. Non-stress test (NST).

Answer: (D)

The non-stress test measures how the fetal heart rate responds to fetal movement. By using external monitors to track the heart rate while the fetus moves, clinicians look for accelerations in heart rate that occur with activity. A reactive result—two or more accelerations within about 20 minutes—suggests the fetus has adequate oxygenation and autonomic function. If there are no accelerations with movement, the test is nonreactive and may lead to further testing. Other options assess different aspects: ultrasound alone shows anatomy or movement but not heart-rate changes tied to movement; a contraction test evaluates heart-rate response to contractions rather than movement; a biophysical profile includes the NST plus additional ultrasound parameters, but isn’t solely about movement-induced heart-rate changes.