Contraction Stress Test (CST)
Contraction Stress Test (CST) ( 5 Questions)
A client asks the nurse about the interpretation of a negative CST result.
What should the nurse explain to the client?
This means that the fetus is well oxygenated and tolerating labor well. A negative CST result is reassuring and has a high negative predictive value.
Late decelerations of the FHR are a sign of fetal hypoxia and placental insufficiency. They occur after the peak of a contraction and are associated with fetal distress.
Variable decelerations of the FHR are caused by cord compression and can occur with or without contractions. They are abrupt decreases in FHR that vary in onset, depth, and duration. They may indicate fetal compromise if they are severe or persistent.
Late decelerations of the FHR with at least 50% of contractions indicate a positive CST result, which means that the fetus is at risk of hypoxia and acidosis.
This means that the fetus is well oxygenated and tolerating labor well. A negative CST result is reassuring and has a high negative predictive value.
Choice B is wrong because late decelerations of the FHR are a sign of fetal hypoxia and placental insufficiency. They occur after the peak of a contraction and are associated with fetal distress.
Choice C is wrong because variable decelerations of the FHR are caused by cord compression and can occur with or without contractions. They are abrupt decreases in FHR that vary in onset, depth, and duration.
They may indicate fetal compromise if they are severe or persistent.
Choice D is wrong because late decelerations of the FHR with at least 50% of contractions indicate a positive CST result, which means that the fetus is at risk of hypoxia and acidosis.
This requires further evaluation and possible intervention.
Normal ranges for FHR are 110 to 160 bpm during late pregnancy and labor. Normal ranges for uterine contractions are 2 to 5 per 10 minutes, lasting less than 90 seconds each.