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nonstress test(NST) [non-stres´]
evaluation of fetal well being during the intrauterine period. Observations of fetal heart rate response to fetal movements are made: a reactive pattern of more than 15 beats per minute above the baseline heart rate twice in 10 minutes is indicative of well being; a nonreactive pattern may indicate asphyxia, maternal medication, fetal anomalies, or a prolonged rest state. See also fetal monitoring.
a test to evaluate fetal well-being by evaluating fetal heart rate response to fetal movement; a reactive nonstress test is fetal heart rate acceleration in response to fetal movement.
An ultrasound examination of a fetus that measures fetal well-being by correlating fetal movement with changes in fetal heartbeat.
nonstress test (NST)
an evaluation of the fetal heart rate response to natural contractile activity or to an increase in fetal activity. Also called fetal activity determination.