Fetal assessment

Question 1

How can you assess fetal wellbeing in labour?

Answer 1

Colour of amniotic fluid
CTG
Fetal blood sampling - pH

Question 2

What is a type 1 vs type 2 deceleration?

Answer 2

Type 1 = peak uterine contraction corresponds with a deceleration
Type 2 aka late deceleration in labour - the trough of deceleration occurs after peak uterine contraction - more concerning of fetal hypoxia

Question 3

What is a deceleration?

Answer 3

Measured on CTG as fetal HR drops 15 beats below baseline, lasting 15 seconds
Decelerations are abnormal in the antepartum period.
Decelerations can occur in labour but persistent decelerations, type 2 are concerning for fetal hypoxia

Question 4

Are accelerations CTG normal?

Answer 4

Yes, 2 acceleration over a 20min period is a reassuring, normal CTG

Question 5

What should the normal fetal pH be?

Answer 5

normal is >7.25
<7.0 -> baby needs to be delivered within 30mins
There is about a 10min window from a deceleration on CTG due acidosis, in which a foetus will survive before becoming extremely hypoxic.

Question 6

What is considered a fetal bradycardia?

Answer 6

HR <100 for 5 mins
If the HR drops below 80, that is insufficient to supply the brain.
There are 4 reasons for the baby becoming hypoxic

Question 7

What is the concern with a fetal tachycardia

Answer 7

Chorioamnionitis - baby needs to be delivered urgently- C section

Question 8

Why would a baby become hypoxic?

Answer 8

Maternal deterioration
Uterus - uterine rupture ( 15-20% risk of death or injury to fetes), risk of hysterectomy, massive blood transfusion
Placenta - placental abruption
Cord prolapse (15-20% death or injury to fetus)

Question 9

Why look at amniotic fluid?

Answer 9

It is an indirect measure of volume of fetal urine output

• should be clear
• may be meconium stained
• meconium 1 - monitor but not too concern
• meconium 2 or 3 - concern of fetal hypoxia

Question 10

Ways to assess fetal wellbeing

Answer 10

Ask about fetal movements - after 28wks should be moving 10times in 12hr period

• US - biometry to assess fetal growth ( biparietal diameter, head circumference, abdo circumference, femur length -> EFW)
• US umbilical artery doppler if concern of IUGR
• US biophysical profile (gross fetal movement, breathing movement, tone and liquor volume) score /8

amniocentesis - rarely done