Growth restriction + macrosomia

Question 1

Define:

• small for dates
• large for dates
• low birth weight
• foetal growth restriction
• foetal macrosomia

Answer 1

• small for dates - <10th percentile of expected growth
• large for dates - >90th percentile of expted growth
• low birth weight - baby weighs <2500g
• foetal growth restriction - baby’s weight has achieved less than it’s expected genetic growth potential
• foetal macrosomia - baby weighs >4000g

Question 2

What are the 3 possible causes for a foetus being small for dates? Give examples.

Answer 2

• mother is small - baby is normal just small
• non-placental mediated - chromosomal abnormalities, in-born errors of metabolism
• placenta mediated - decreased blood flow to placenta (smoking HTN, DM), placental abruption or praevia, infection

Question 3

What are some risk factors for a small for dates foetus? Maternal, Foetal and placental?

Answer 3

• maternal - smoking, DM, HTN, >age, infection (ToRCH), lots of exercise, undernourished, previous still birth, substance misuse
• Foetal - chromosomal abnormalities, dysmorphic features, infection
• placental - fibroids, site of implantation (praevia), APH

Question 4

How is the diagnosis of small for dates made?

Answer 4

• foetal abdominal circumference OR expected weight on USS

- serum test for ToRCH infections

Question 5

What does the acronym TORCH stand for?

Answer 5

• Toxoplasmosis
• Rubella
• CMV
• Herpes

Question 6

How do you manage an small for dates foetus?

Answer 6

• antiplatelet may be useful here to reduce risk of pre-eclampsia (low dose aspirin)
• antenatal steroids, 24-35 weeks, where delivery is being considered

Delivery
-if uterine artery compromised C-section

Post-partum

• early feeding
• keep warm
• increased risk of neonatal jaundice

Question 7

What investigations would be done for a small for dates foetus?

Answer 7

• USS + umbilical and uterine artery doppler
• amniotic fluid volume measurement
• CTG
• karyotyping if bab is small

Question 8

What does an symmetrical or asymmetrical growth restriction tell you about the pregnancy?

Answer 8

• asymmetrical = head grows to normal size and body is small = problem with placental blood flow or maternal nourishment
• symmetrical = central problem with foetus

Question 9

Risk factors/causes of large for dates foetus?

Answer 9

• maternal obesity
• excessive weight gain during pregnancy
• maternal diabetes
• overdue pregnancy
• previous large for fates foetus

Question 10

What investigations would you perform in a ?large for dates foetus?

Answer 10

• maternal blood sugars - HbA1C + OGTT

- USS w/ doppler

Question 11

How would you treat gestational diabetes?

Answer 11

• lifestyle advice
• oral metformin
• C-section to avoid shoulder dystocia