Nonstress test

Overview
The nonstress test or NST is a Doppler time series recording of the heart beat of a fetus in utero simultaneous with the abdominal and/or uterine contractions of the pregnant woman.

Interpretation

 * The NST is part of the biophysical profile, a formal prenatal test for fetal well being.


 * The NST is considered reactive (a good sign) if the fetal heart rate has two accelerations in 20 minutes that (1) are at least 15 beats per minute above the baseline heart rate and (2) last for at least 15 seconds.


 * A sleeping fetus, which appears nonreactive, can be awakened. This is often done by giving the woman a drink that is cold and/or sugary.