Foetal growth restriction

Question 1

Definition of small for gestational age (SGA)

Answer 1

• Abdominal circumference (AC) or estimated foetal weight (EFW) less than the 10th centile
• Normal doppler scan - Sufficient blood flow

Question 2

Definition of severe small for gestational age (SGA)

Answer 2

AC or EFW < 3rd centile

Question 3

Definition of foetal growth restriction (FGR)

Answer 3

• Failure of the foetus to attain their growth potential
• All babies will be below 3rd centile or below 10th with placental dysfunction
• Abnormal doppler - Blood flow insufficient

Question 4

Definition of low brith weight (LBW)

Answer 4

Any baby born with a weight of 2.5kg (5.5lbs) at any gestation

Question 5

What are some antenatal risks of FGR and SGA

Answer 5

hypoxia and stillbirth

Question 6

Post-natal risks of FGR and SGA

Answer 6

• Hypoglycaemia
• Asphyxia
• Hypothermia
• Polycythaemia
• Hyperbilirubinaemia
• Abnormal neurodevelopment
• Complications of prematurity

Question 7

Maternal causes of SGA

Answer 7

• Lifestyle - Smoking, alcohol, drugs
• Very low or high BMI
• Age
• Maternal diseases - E.g. hypertension, renal disease

Question 8

Placental causes of SGA

Answer 8

• Infarctions
• Abruptions (Antepartum haemorrhage - APH)
• Association with hypertensive diseases (E.g. pre-eclampsia)

Question 9

Foetal causes of SGA

Answer 9

• Infection - E.g. Rubella, CMV, Toxoplasmosis
• Congenital abnormalities
• Chromosomal abnormalities

Question 10

Risk factors for SGA

Answer 10

• Maternal age > 40
• Nulliparity
• Low or High BMI (<19, >35)
• Maternal substance use
• IVF pregnancy
• Daily vigorous exercise
• Previous SGA baby or stillbirth
• Maternal SGA
• Echogenic bowel
• Fibroids
• Conditions such as chronic HTN, diabetes with vascular disease, renal impairment, antiphospholipid syndrome, paternal SGA

Question 11

What are some ways of preventing SGA

Answer 11

• Aspirin for those at risk of pre-eclampsia
• Vitamin D supplementation
• Smoking cessation (Cessation before 15 weeks reduces risk to same as a non-smoker)
• Drug service input
• LMWH in antiphospholipid syndrome

Question 12

What is SFH

Answer 12

Symphysis-Fundal height

Question 13

What investigations are required in those at moderate risk of SGA

Answer 13

Serial USS from 32 weeks every 4 weeks until delivery

Question 14

What investigations are required in those at high risk of SGA

Answer 14

Uterine artery doppler then serial USS (Dates depend on uterine artery doppler results)

Question 15

When is SFH usually measured?

Answer 15

At every appointment from 24 weeks

Question 16

When is growth scanning indicated in SFH measurement

Answer 16

If SFH growth chart is below 10th gentile, is static or the curve crosses centiles

Question 17

Advantages of SFH measurement

Answer 17

• Cheap
• Easy and available
• Better continuity of care

Question 18

What 3 measurements are done on USS fro foetal growth

Answer 18

• Measurement of abdominal circumference (AC)
• Measurement of head circumference
• Measurement of femur length

Question 19

What is EFW?

Answer 19

Estimated foetal weight (EFW)

Question 20

What is liquor?

Answer 20

Fluid surrounding the baby

Question 21

What produces the liquor

Answer 21

Placenta and baby

Question 22

What are some measurements of liquor volume?

Answer 22

Deepest vertical pool (DVP)
Amniotic Fluid Index (AFI)

Question 23

Normal DVP

Answer 23

2-10cm

Question 24

What are some forms of doppler scan done in assessment of foetal growth

Answer 24

Umbilical artery doppler
Middle cerebral artery doppler
Ductus venosus doppler

Question 25

Characteristics of umbilical artery doppler

Answer 25

The umbilical artery should be low resistance with forward flow throughout the maternal cardiac cycle Pulsatility index can be measures, which reduces as gestation advances <1.4 is always normal This flow can be absent or reversed

Question 26

What is shown in a, b and c

Answer 26

1. Normal blood flow 2. Absent end-diastolic flow 3. Reversed end-diastolic flow

Question 27

Characteristics of middle cerebral artery doppler

Answer 27

This indicates brain perfusion There will be a reduced pulsatility index in a compromised foetus There is increased peak systolic velocity in foetal anaemia This is useful as an additional marker for SGA/FGR after 32 weeks

Question 28

Characteristics of ductus venosus doppler

Answer 28

This is a direct reflection of foetal heart function This will show A-waves: - Flow during atrial contraction of the foetal heart - Becomes progressively deeper as foetal condition worsens This is used to time delivery and is particularly useful in preterm FGR

Question 29

Management of AC/EFW in gentile 3-10

Answer 29

- Fortnightly scans for foetal growth, DVP and dopplers - Esnure regular BP and urine check - Advice on symptoms of pre-eclampsia - Advice about increased risk of stillbirth and to report reduced movements immediately - Offer induction of labour at 39 weeks and aim to delivery by 39+6

Question 30

Management of AC/EFW gentile < 3

Answer 30

- Once weekly monitoring of foetal dopplers - Computerised CTG - Monitor for pre-eclampsia - Clear advice on stillbirth risk - Deliver at 37 weeks, no later than 37+6