non-stress test
A prenatal monitoring test that records fetal heart rate patterns and uterine contractions to assess fetal well-being.
Full Definition
The non-stress test (NST) is a non-invasive prenatal surveillance tool used to evaluate fetal well-being by monitoring fetal heart rate patterns in response to fetal movement. The test is typically performed using external cardiotocography monitors placed on the maternal abdomen. A reactive NST shows at least two fetal heart rate accelerations of 15 beats per minute above baseline lasting at least 15 seconds within a 20-minute period. A non-reactive NST may indicate fetal compromise and often requires additional testing such as a biophysical profile or contraction stress test. NSTs are commonly used for high-risk pregnancies, post-term monitoring, and assessment of fetal growth restriction.
Usage
Usage note: Hyphenate when used as a compound modifier. Commonly abbreviated as NST in medical records.
In Context
- "The non-stress test showed a reactive pattern with appropriate accelerations and no concerning decelerations." — Antepartum testing report
- "Given the non-reactive NST, a biophysical profile was ordered for further evaluation." — Clinical decision documentation