The nurse recognizes that a nonstress test (NST) in which two or more fetal heart rate (FHR) accelerations of 15 beats/min or more occur with fetal movement in a 20-minute period is:
A.
Negative.
B.
non-reactive.
C.
reactive
D.
Positive.
The Correct Answer and Explanation is:
The correct answer is C. reactive.
Explanation:
A nonstress test (NST) is a common prenatal test used to assess fetal well-being, particularly the fetal heart rate (FHR) and its response to fetal movements. The primary goal of the NST is to evaluate how well the fetus is handling the stress of pregnancy and to ensure adequate oxygenation and overall fetal health.
The NST involves monitoring the fetal heart rate with an electronic fetal monitor and assessing its response to fetal movements. The test is considered “reactive” if it meets specific criteria:
- Fetal Heart Rate Accelerations: The test is deemed reactive if there are two or more fetal heart rate accelerations of 15 beats per minute or more above the baseline, lasting for at least 15 seconds each, within a 20-minute period. This indicates that the fetus is responding well to movements, suggesting good oxygenation and a healthy autonomic nervous system.
- Baseline Fetal Heart Rate: The baseline fetal heart rate is typically between 110 and 160 beats per minute. Acceleration in this range is a positive sign of fetal well-being.
In contrast:
- Negative: This term is often used in reference to a test result that is not concerning, such as a negative contraction stress test, but it is not typically used to describe the NST.
- Non-reactive: This result indicates that the test did not show the expected FHR accelerations in response to fetal movements. It could suggest potential issues such as fetal distress or inadequate oxygenation, and may necessitate further testing or monitoring.
- Positive: In the context of the NST, “positive” is not used. It is more relevant to the contraction stress test, where a positive result may indicate that the fetus does not tolerate contractions well.
Thus, a NST with two or more FHR accelerations of 15 beats per minute or more in a 20-minute period is considered reactive, reflecting a reassuring fetal condition.