With reference to fetal heart rate, a non-stress test is considered reactive when: (AIIMS Nov 2011)
|A||Two fetal heart rate accelerations are noted in 20 mins|
|B||One fetal heart rate acceleration is noted in 20 mins|
|C||Two fetal heart rate accelerations are noted in 10 mins|
|D||Three fetal heart rate accelerations are noted in 30 mins|
Two fetal heart rate accelerations are noted in 20 mins
a. Non-Stress Test: It is a non-invasive test designed to monitor fetal responses to movements by correlating fetal heart rate with perceived fetal movements.
b. With movement, the fetus will increase its heart rate and should maintain this increase for several seconds.
c. If the movement stresses the fetus, the heart rate will drop quickly.
d. This test monitors the acceleration of heart rate and whether the fetus becomes stressed or not.
e. The mother is asked to lay down for 2040 minutes while the fetal heart rate is recorded with a disc-shaped Doppler ultrasound strapped around her abdomen, similar to the Doppler equipment used to listen to the fetal heart rate.
f. The Doppler is attached to a monitor that graphs the fetal heart rate. She will report each time she feels the baby move by pressing a button that makes an arrow on the graph.
g. A normal fetus will raise its heart rate at least 15 beats whenever it moves.
h. If the baby shows two accelerations in heart rate lasting at least 15 seconds during the 20-minute test, it is read as normal or "reactive."
i. A reactive non-stress test (NST) is a reassuring sign of fetal well-being. If the heart rate does not accelerate with movement or another 20 minutes of observation fails to meet the criteria, and then the non-stress test is considered "non-reactive."