Fetal bradycardia

Question 1

Definition fetal bradycardia

Answer 1

FHR< 100bpm for >5 minutes

Question 2

Initial management of fetal bradycardia

Answer 2

1. Reposition the mother to limit cord compression and improve her blood pressure, (left lateral)
2. Correct the maternal blood pressure as required (IVF)
3. Eliminate the uterine activity, if present, with 250μg SC terbutaline (or equivalent) and stop synto

Then:

4. VE to assess dilatation, apply FSE, exclude cord prolapse, determine mode of birth

Question 3

Causes of fetal bradycardia

Answer 3

Non-hypoxic:

• Fetal heart block
• Mature parasympathetic system
• Medication

Hypoxic:

• Uterine hyperstimulation (by tachysystole or hypertonus)
• Maternal hypotension (positional, procedural or anaesthetic)
• Sustained umbilical cord compression, including cord prolapse
• A rapid descent of the fetal head through the pelvis.
• Placental abruption,
• Placental infarction,
• Uterine rupture
• Maternal hypoxia.

Question 4

At what rate does the fetal pH fall during bradycardia?

Answer 4

0.01 every 2–3 minutes

Question 5

What is the ‘rule of 3s’?

Answer 5

3 minutes – call for help
6 minutes – move to theatre
9 minutes – prepare for assisted delivery
12 minutes – aim to deliver the baby.