5.2a Basis of Fetal Monitoring

Question 1

Fetal Oxygen Decrease Causes

Answer 1

Reduction of blood flow due to
- Hypertension (chronic, gestational, preeclampsia)
- Hypotension (supine position, hemorrhage, epidural)
- Hypovolemia (hemorrhage)
Reduction of Oxygen in the blood due to
- Hemorrhage/Anemia
Alterations in Circulation due to
- Compression of umbilical cord during contraction
- Placental separation/abruption
- Head compression

Question 2

FHR

Answer 2

• Abnormal patterns are associated with hypoxemia which can turn to hypoxia
• Inadequate oxygen can cause metabolic acidosis

Question 3

Intrapartum Fetal Surveillance

Answer 3

• Detect events that can compromise fetal oxygenation

External Monitoring - Doppler Device
Internal Monitoring - Fetal Scalp Electrode

Question 4

Fetal Heart Rate Monitoring

Answer 4

Baseline - 110-160 bpm
Bradycardia - <110
Tachycardia - >160

Question 5

Variability

Answer 5

• Beat to Beat change in fetal heart rate

Absent - No variation
Minimal - <5 variability from beat to beat
Moderate - 6-25 variability from beat to beat
Marked - >26 variability from beat to beat

Moderate Variability is the best. It shows adequate oxygenation and normal brain function of fetus.

Decreased Variability - Hypoxia, Acidemia, Tachycardia, CNS/Cardiac Anomalies, Morphine/Magnesium, Prolonged Uterine Contraction

Question 6

VEALCHOP

Answer 6

V - Variable Deceleration (Rapid drop and Rapid Recovery. Looks like V)
C - Cord Compression (Cause of Variable Deceleration)
E - Early Deceleration (Slow onset and slow recovery that corresponds with start and end of contraction)
H - Head Compression (Cause of Early Deceleration and is good)
A - Acceleration (Increases in fetal heart rate)
O - Okay, it is good.
L - Late deceleration (fall and rise in FHR after peak of uterine contraction)
P - Caused by placental Insufficiency and is bad.

Question 7

Fetal Heart Rate Tracings

Answer 7

Category 1

• Baseline 110-160
• Moderate variability
• No late/variable deceleration

Category 3 (Immediate Delivery is Needed)
- Absent variability
- Recurrent late decelerations
- Bradycardia
- Sinusoidal Wave Pattern (unusual smooth wave lines that persist for over 20 minutes)
(Requires Immediate Delivery)

Category 2
- Everything in between.