Antenatal Tests I: Imaging

Question 1

In what circumstances do we use ultrasound in pregnancy

Answer 1

• Confirm location/viability
• Date the pregnancy
• Check for abnormalities (e.g. nuchal translucency)
• Track growth/position; prepare for delivery

Question 2

What’s the new model we’re moving toward re when scans occur in pregnancy?

Answer 2

• Dating/viability scan 8 weeks for accurate d8’s
• Scan at twelve weeks to check for lethal abnormalities (early as possible for less traumatic termination)
• Later morphology scan at 22 weeks (less serious abnormalities, check placental position [why?])
• Growth scan at 36wks to check late-onset growth restriction

Question 3

What do we measure during d8ing and viability scan?

Answer 3

Crown-rump length.

Question 4

What conditions are associated with increased nuchal translucency of a fetus on US?

Answer 4

• Patau’s, Edward’s, Down’s syndromes
• Turner’s syndrome
• Cardiac abnormalities
• Noonan’s syndrome (what is this, broadly?)

Question 5

What is the purpose of a morphology scan (US)?

Answer 5

• Check for fetal abnormalities, placental position, amniotic fluid volume
• Check for any maternal problems (fibroids, ovarian cysts)

Question 6

What is the typical pregnancy timeframe of morphology scanning?

Answer 6

18-20 weeks