Nonstress test

Nonstress test
Medical diagnostics
ICD-9-CM	75.34
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A nonstress test (NST) is a screening test used in pregnancy. A is used to monitor the fetal heart rate.

The premise of the NST is that a well-oxygenated, non-acidemic fetus will spontaneously have temporary increases in the fetal heart rate (FHR).

Vibroacoustic stimulation can wake the fetus, and is sometimes used to speed up the test or to facilitate further evaluation of a nonreactive nonstress test.

A nonstress test can be classified as normal, atypical, or abnormal. A normal nonstress test will show a baseline fetal heart rate between 110-160 beats per minute with moderate variability (5-25 interbeat variability) and 2 qualifying accelerations in 20 minutes with no decelerations.

Previous terminology: Reactive/non-reactive:

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