Small for gestational age

Question 1

What is a small for gestational age (SGA) infant?

Answer 1

Infant born with birthweight below 10th centile for it’s gestational age

Question 2

What is a low birthweight (LBW)?

Answer 2

Infant with birthweight <2500g

Question 3

What is foetal growth restriction?

Answer 3

A pathological process that has restricted the genetic growth potential.

Question 4

Aetiology for normal (constitutionally) small?

Answer 4

• No pathology present
• Contributing factors include ethnicity, sex and parental height
• Around 50-70% of SGA foetuses are constitutionally small

Question 5

Aetiology for placenta mediated growth restriction?

Answer 5

• Growth is usually normal initially but slow in utero (in uterus) - common cause of FGR (foetal growth restriction)
• Maternal factors that can result in placental insufficiency include:
  • Low pre-pregnancy weight
  • Substance abuse
  • Autoimmune disease
  • Renal disease
  • Diabetes
  • Chronic hypertension

Question 6

Aetiology for non-placenta mediated growth restriction?

Answer 6

• Infection e.g. rubella, CMV
• Congenital anomalies e.g. absent kidneys
• Multiple pregnancy (having more than one child at once).

Question 7

At what point of gestation should women be assessed for risk factors of SGA?

Answer 7

20 weeks gestation

Question 8

What imaging technique is used for the diagnosis and surveillance of an SGA foetus?

Answer 8

Ultrasound biometrics including EFW (estimated foetal weight) and AC (foetal abdominal circumference), plotted on customised centile charts

Question 9

What are other appropriate investigations for SGA?

Answer 9

• Detailed foetal anatomical survey
• Uterine artery doppler
• Karyotyping
• Screening for infections e.g. toxoplasmosis, syphilis, malaria etc.

Question 10

Preventative management for SGA?

Answer 10

• Modifiable risk factors should be managed to help prevent SGA. These include: promoting smoking cessation and optimising maternal disease.
• 150mg aspirin at night from 12 weeks in women with risk factors for pre-eclampsia.

Question 11

Surveillance management for SGA?

Answer 11

• Serial scans for growth with umbilical doppler
• Schedule individualised according to the risk factors

Question 12

Neonatal complications of SGA?

Answer 12

• Birth asphyxia
• Hypothermia
• Meconium aspiration
• Retinopathy of prematurity
• Pulmonary haemorrhage

Question 13

Long term complications of SGA?

Answer 13

• T2DM
• Obesity
• Hypertension
• Cerebral palsy
• Precocious puberty
• Cancer
• Alzheimer’s disease
• Depression

Question 14

What is a uterine artery doppler and it’s use?

Answer 14

used to check the blood flow of the uterine arteries.

The flow of blood in the vessels can inform us as to whether your baby will grow to its full potential and the likelihood of developing pre-eclampsia