Antenatal Care

Question 1

Trisomys that can be screened for in 1st trimester

Answer 1

Trisomy 21 (Down's syndrome)
Trisomy 18 (Edward's syndrome)
Trisomy 13 (Patau's syndrome)

Question 2

How and when is trisomy screening done in 1st trimester

Answer 2

Combined test at 11-14wks

Nuchal translucency + hCG + PAPP-A (combined test)

Question 3

What size of nuchal translucency is associated with pregnancy problems?

Answer 3

> 3.5mm

Question 4

Trisomys that can be screened for in 2nd trimester

Answer 4

Trisomy 21 (Down’s syndrome) only

Question 5

How and when is trisomy screening done in 2nd trimester?

Answer 5

Quadruple test at 15-20wks

AFP, hCG, unconjugated oestradiol, inhibin A

Question 6

What is NIPT?

Answer 6

Non-Invasive Prenatal Testing (NIPT)
Secondary screening test
Foetal DNA in maternal blood sample

Question 7

Can TOP be done based on NIPT results?

Answer 7

No

Need to have a diagnostic test

Question 8

Diagnostic antenatal genetic tests

Answer 8

CVS

Amniocentesis

Question 9

CVS timing

Answer 9

11-14wks

Question 10

Amniocentesis timing

Answer 10

15-20wks

Question 11

Amniocentesis vs CVS, which has a higher miscarriage rate

Answer 11

CVS (but only slightly)