Prenatal Diagnostic Tests And Procedures > Maternal & Newborn
Exam Review
Contraction Stress Test (CST)
Total Questions : 5
Showing 5 questions, Sign in for moreA nurse is explaining the Contraction Stress Test (CST) to a pregnant client.
Which statement accurately describes a positive CST?
Explanation
Late decelerations of the FHR with at least 50% of contractions.This indicates a positive CST, which means that the baby may be under stress and unable to tolerate labor contractions.A positive CST may require a cesarean section or further observation.
Choice B is wrong because late decelerations of the FHR with less than 50% of contractions indicate an equivocal CST, which means that the results are unclear and the test may need to be repeated.
Choice C is wrong because no late decelerations of the FHR during contractions indicate a negative CST, which means that the baby is healthy and can handle the stress of labor.
Choice D is wrong because variable decelerations of the FHR with or without contractions indicate cord compression, not placental insufficiency, which is what the CST is testing for.
A client is scheduled for a Contraction Stress Test (CST).
When should the CST be performed?
Explanation
A contraction stress test (CST) is performed near the end of pregnancy (34 weeks’ gestation) to determine how well the fetus will cope with the contractions of childbirth.The test triggers contractions and monitors the fetal heart rate using a cardiotocograph.A normal heartbeat is a good sign that the fetus will be healthy during labor.
Choice A is wrong because a CST is usually done after 32 weeks of gestation, not before 28 weeks.Doing the test too early may not be safe for the fetus.
Choice C is wrong because a CST is not only done for clients with diabetes mellitus.It may be done for clients who have complications during their pregnancy or who have abnormal results from other tests, such as a nonstress test or a biophysical profile.
Choice D is wrong because a CST is not only done for clients with hypertension.It may be done for clients who have complications during their pregnancy or who have abnormal results from other tests, such as a nonstress test or a biophysical profile.
A nurse is preparing a pregnant client for a Contraction Stress Test (CST).
What is the purpose of inducing uterine contractions during the test?
Explanation
The purpose of inducing uterine contractions during the test is to simulate labor contractions and check how the baby’s heart rate reacts to the stress of reduced blood and oxygen supply.A normal heart rate indicates that the baby will be healthy during labor.
Choice B is wrong because monitoring the FHR is not the purpose of the test, but a means to assess fetal well-being.
Choice C is wrong because achieving at least three contractions lasting 40 to 60 seconds is not the purpose of the test, but a criterion for a satisfactory test.
Choice D is wrong because identifying fetal hypoxia or distress is not the purpose of the test, but a possible outcome of an abnormal test.
A client asks the nurse about the interpretation of a negative CST result.
What should the nurse explain to the client?
Explanation
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.
During a CST, the nurse notices late decelerations of the FHR with at least 50% of contractions.
How should the nurse interpret this finding?
Explanation
Late decelerations of the FHR are a sign of uteroplacental insufficiency, meaning that the placenta is not delivering enough oxygen to the fetus.
This can lead to fetal distress and hypoxia.
A positive CST result means that there is evidence of fetal compromise during uterine contractions.
Choice B is wrong because a negative CST result would mean that there are no late decelerations or significant variable decelerations of the FHR with at least three contractions in 10 minutes.
This would indicate adequate fetal oxygenation and normal placental function.
Choice C is wrong because an equivocal CST result would mean that there are either variable decelerations of the FHR with more than 50% of contractions, or late decelerations with less than 50% of contractions.
This could indicate cord compression, fetal head compression, or mild fetal hypoxia.
Choice D is wrong because an unsatisfactory CST result would mean that there are either no contractions in 10 minutes, or less than three contractions in 10 minutes with an uninterpretable FHR tracing.
This would require repeating the test or performing a biophysical profile (BPP) to assess fetal well-being.
Sign Up or Login to view all the 5 Questions on this Exam
Join over 100,000+ nursing students using Nursingprepexams’s science-backend flashcards, practice tests and expert solutions to improve their grades and reach their goals.
Sign Up Now
