What happens to the fetal heart rate during activity as measured by the nonstress test?

During physical activity, the fetal heart rate typically increases, which is reflected in nonstress test (NST) results. This elevation in heart rate is a normal physiological response, indicating that the fetus is reacting to increased demand for oxygen and nutrients during the mother's movement. The heart rate acceleration is a reassuring sign that the fetus is well-oxygenated and responding appropriately to stimuli.

A nonstress test specifically monitors fetal heart rate patterns in response to fetal movement. In a healthy fetus, the heart rate will generally rise with activity. An increase in fetal heart rate greater than 15 beats per minute for at least 15 seconds is often considered a sign of good fetal well-being. This supports the interpretation that a robust heart rate response correlates with a healthy, reactive fetus, especially under the influence of maternal activity.

This increased heart rate serves as an important indicator during prenatal assessments, helping healthcare providers ascertain the baby's health and well-being in utero.