Summary

1. Fetal non-stress test (NST) is a screening test that measures FHR response to fetal movement.

2. It is used to assess fetal well-being and oxygenation in high-risk pregnancies or when there is decreased fetal movement or growth restriction.

3. It is performed after 28 weeks of gestation by placing two transducers on the mother’s abdomen and recording FHR and uterine activity for at least 20 minutes.

4. A reactive result means that FHR increases by at least 15 bpm for at least 15 seconds twice in 20 minutes. A nonreactive result means that FHR does not show this pattern in 40 minutes.

5. Other FHR characteristics include baseline rate, variability, accelerations, and decelerations. Normal baseline rate is 110 to 160 bpm; normal variability is moderate; accelerations are reassuring; early decelerations are benign; late decelerations are abnormal; variable decelerations are abnormal.

6. Nursing interventions include explaining the test; monitoring FHR and uterine activity; documenting fetal movements and interventions; providing emotional support and education; interpreting results; reporting results; providing referrals; providing follow-up care.

7. NST can be compared with CST which measures FHR response to induced contractions. CST causes stress to the fetus while NST does not. Both tests assess FHR patterns related to fetal oxygenation. Negative CST means no late or significant variable decelerations; positive CST means late or significant variable decelerations.

8. Advantages of NST include safety; simplicity; noninvasiveness; low cost; wide availability; high tolerance; high negative predictive value; repeatability. Limitations of NST include low positive predictive value; false-positive or false-negative results; lack of information on other aspects of fetal well-being.