5.) FHR Monitoring NST CST Interpretation Of Results

Question 1

What is NST?

Answer 1

Non-stress test it evaluates fetal heart rate responses to fetal movements giving on indications of fetal oxygenation and well-being. It does not involve any external stress on the fetus.

Question 2

What is the procedure for an NST?

Answer 2

• The mother is placed in a reclining or semisitting position
• Two monitors are strapped around the mothers abdomen one to record fetal heart rate and one to record uterine contractions
• The fetal heart rate is recorded for 20 to 30 minutes to observe its response to fetal movements

Question 3

What is a reactive NST?

Answer 3

This is a good result. It means two accelerations in fetal heart rate increases of at least 15 bpm lasting 15 seconds within a 20 minute period this suggests good fetal oxygenation.

Question 4

What is a non reactive NST

Answer 4

Bad result , Less than 2 accelerations within 20 mins which may suggest fetal distress or hypoxia.

Question 5

What is a CST and what is the procedure to conduct one?

Answer 5

A contraction stress test evaluates placental oxygenation and function and tests the fetus ability to cope with the stress of labour. It is typically performed if the NST results are abnormal.

The mother is placed in a reclining position and two monitors are placed on the abdomen a 20 minute baseline is recorded. Oxytocin is given aiming for three contractions lasting for 40 seconds or more within a 10 minute period.

Question 6

What is a negative CST ?

Answer 6

This is a good result. It indicates no late decelerations during contractions. The fetus is likely to tolerate labour well

Question 7

What is a positive CST ?

Answer 7

This is a bad result

Late decelerations with at least 50% of contractions the fetus may not tolerate labour well this result often suggest uteroplacental insufficiency a C-section may be necessary or tocolytic therapy to suppress uterine contractions example nifedipine or calcium channel blocker to relax smooth muscle of the uterus or hyper oxygenation also is an option to improve fetal oxygen

Question 8

What are decelerations in fetal heart rate?

Answer 8

So we have early deceleration this is commonly seen in second stage of labour it occurs due to compression of the fetal head during contractions or pushing activates the vagus nerve usually not a concern and resolves after the contraction

• Late decelerations occurs after the peak of the contraction and is a sign of uteroplacental insufficiency could require a C-section
• variable decelerations occurs due to the umbilical cord compression and unrelated to contractions