Foetal Growth Restriction

Question 1

Define Fatal growth restriction (FGR)

Answer 1

Failure of the fetus to achieve its predetermined growth potential for various reasons

Question 2

Define small gestational age (SGA)

Answer 2

Birth weight <10th centile

Question 3

Describe low birthweight babies (growth restriction, delivery time, morbidity and mortality, pathology)

Answer 3

Most LBW neonates are NOT growth restricted
Many FGR babies are delivered prematurely
3-10 fold increase in perinatal morbidity and mortality
LBW, FGR and preterm delivery have closely associated pathologies

Question 4

Which centile is the most sensitive

Answer 4

10th is the most sensitive

The tenth centile will capture all babies with FGR, but will also include those babies that are just small for gestational age, i.e. you get a number of false positives.

Question 5

Which centile is the most specific

Answer 5

3rd is the most specific
All babies recorded using the third centile will have FGR, but some FGR babies may be missed, i.e you get a number of false negatives.

Question 6

What is the difference between gestational age and foetal age

Answer 6

GA is 2 weeks greater than FA. FA starts post fertilisation

Question 7

What are the consequences of Intrauterine growth restriction (IUGR)

Answer 7

it has serious consequences for babies who survive (most common factor in stillborn)
There is an increased risk of IUGR and intrauterine death (IUD) in mother’s subsequent pregnancy.

Question 8

What are the maternal causative factors of FGR

Answer 8

Smoking 
Diabetes 
Anaemia 
<16 
>25

Question 9

What are the foetal causative factors of FGR

Answer 9

Multiple pregnancy
Chromosome abnormality
Inborn errors of metabolism

Question 10

When are ‘at risk’ patient screened and what makes them ‘at risk’

Answer 10

24 weeks

PAPP-A < 0.3 MoM (Pregnancy associated plasma proteinA)
POHxPET/FGR (past obstetric history of Preclampsia/ fetal growth restriction)

Question 11

What is screened for in “at risk” pregnancies

Answer 11

Maternal systemic disease e.g. HT< renal, sickle
Uterine artery Doppler in 1st/2nd trimester (blood flow in uterine arteries -> find high resistance flow)
Serial foetal biochemistry.

Question 12

Define pre-eclampsia

Answer 12

Multisystem disease that usually manifests as hypertension and proteinuria
BP > 140/90mmHg
Proteinuria > 0.3g/24hour (PCR>30)

Question 13

How does pre-eclampsia lead to IUGR

Answer 13

Normal exchange of nutrients is not possible

Due to inappropriate spiral artery remodelling

Question 14

What may constitute a bad obstetric history

Answer 14

Previous maternal hypertension
Previous FGR
Stillbirth
Placental Abruption

Question 15

When is delivery aimed for

Answer 15

≥28 weeks

and / or ≥500g

Question 16

Describe the timing of delivery in pregnancies complicated by FGR

Answer 16

Timing delivery in these pregnancies depends on balancing the risks to the fetus if it remains in utero and the hazards from the prematurity, which decrease as the gestation advances

Question 17

What is required if the baby is born less than 36 weeks

Answer 17

Corticosteroids

Question 18

Is late IUGR or early IUGR easier to manage

Answer 18

Late

Early IUGR: 1%, usually linked to maternal disease e.g. PEC, difficult to manage because of risk of prematurity

Late IUGR: 5-7%, rarely linked to PEC, difficult to differentiate from SGA, easily managed by delivery

Question 19

Describe the growth of the baby if a dating problem is the cause of SGA

Answer 19

Consistent growth

Normal dopplers and fluid

Question 20

Describe the growth of the baby if placental insufficiency is caused by a foetal problem

Answer 20

Reduction in AC/FL
Reduced liquor
Deranged doppler

Question 21

Describe the growth of the baby if SGA is caused by a foetal problem

Answer 21

Fetal abnormality