CTG

Question 1

How much rest is needed between contractions to prevent hypoxia?

Answer 1

60-90seconds

Question 2

How many contractions per 10 minute period is optimal?

Answer 2

3-4 per 10 mins.

Question 3

How does maternal HTN cause hypoxia?

Answer 3

Vasoconstriction leads to reduced uterine blood flow which results in placental damage and the fetus’ metabolic needs not being met.

Question 4

What does maternal hypotension do to the fetus?

Answer 4

Reduces 02 available to the fetus and results in hypoxia.

Question 5

What is the baby’s “oxygen tank”?

Answer 5

intervillous space.

Question 6

What happens when there are too many contractions or the contractions last too long?

Answer 6

The fetus’ energy reserves are depleted.

Question 7

What are the 4 components of a normal AN CTG?

Answer 7

1. Baseline 110-160bpm
2. Normal baseline variability (6-25bpm amplitude)
3. 2 accelerations within 20mins (15 up and across)
4. No decelerations

Question 8

Where on a CTG do you measure baseline?

Answer 8

In the absence of movement, contraction or during a sleep cycle.

Question 9

What are the 4 signs of a normal intrapartum CTG?

Answer 9

1. Baseline 110-160bpm
2. Normal baseline variability (6-25bpm amplitude)
3. Accelerations (15 up and across)
4. No decelerations

Question 10

How long is a fetal sleep cycle usually? Why do you not measure baseline during sleep/

Answer 10

Around 20mins.
HR is slightly increased due to the parasympathetic input being withdrawn.

Question 11

Are premis sympathetically or parasympathetically dominent?

Answer 11

Sympathetically.

Question 12

What does variability represent?

Answer 12

The upstroke represents symp input and the downstroke represents para input.

Question 13

What is the difference between increased, normal, reduced and absent variability?

Answer 13

Increased - >25bpm
Normal - 6-25bpm
Reduced - 3-5bpm
Absent - <3bpm almost straight line.

Question 14

What is an acceleration?

Answer 14

15bpm above baseline for 15+ seconds.
Response to stimulation.
Increased sympathetic stimulation - Increased CO & 02 demands.

Question 15

What is tachysystole?

Answer 15

More than 5 contractions in 10mins, without fetal heart rate abnormalities.

Question 16

What is uterine hypertonus?

Answer 16

Contractions that last more than 2 mins OR occur within 60 secs of each other, without fetal abnormalities.

Question 17

What is uterine hyperstimulation?

Answer 17

Tachysystole OR uterine hypertonus WITH FHR abnormalities.

Question 18

What does this CTG show in regards to the uterine activity?

Answer 18

Tachysystole. It could be classed as

Question 19

What uterine activity does this CTG show?

Answer 19

Tachysystole, due to the amount of contractions there is not enough rest to adequately oxygenate the fetus. The CTG shows the fetus is well oxygenated but if those contractions continue the fetus will be compromised.

Question 20

What uterine activity does this CTG represent?

Answer 20

Uterine hypertonus. Each contraction is lasting 2-3 minutes. The fetus is doing well at that point but is at risk.

Question 21

What does this CTG show?

Answer 21

Uterine Hyperstimulation. 5+ contractions in a 10minute period. Fetus is showing prolonged decelerations and bradycardia.

Question 22

What does this CTG show?

Answer 22

A acutely hypoxic fetus. Tachycardic with prolonged and late decelerations. With absent baseline variability.

Question 23

What is fetal bradycardia?

Answer 23

A fall in baseline for more than 5mins.