8.4 Down's Screening

Question 1

When is the combined test for trisomy 21 done?

Answer 1

COMBINED TEST 11-14 weeks US and blood

Question 2

What is measured to show increased risk of Downs in the Combined Test?

Answer 2

• Nuchal translucency over 6mm
• increased BETA-HCG
• decreased PAPPA (pregnancy associated plasma protein A)

(COMBINED TEST 11-14 weeks US and blood)

Question 3

When is the triple test for Downs done?

Answer 3

TRIPLE TEST 14-20weeks, blood only

Question 4

What is measured to show increased risk of Downs in the Triple Test?

Answer 4

• increased BETA-HCG
• decreased AFP
• decreased SERUM OESTRIOL

(TRIPLE TEST 14-20weeks, blood only)

Question 5

When is the quadruple test for Downs done?

Answer 5

QUADRUPLE TEST 14 -20 weeks, same as triple but with an extra blood test

Question 6

What is measured to show increased risk of Downs in the Quadruple Test?

Answer 6

• increased BETA-HCG
• decreased AFP
• decreased SERUM OESTRIOL

plus:
- risk increased with INHIBIN-A

Question 7

After the combined, triple or quadruple test what is done?

Answer 7

Tests give Risk Score;
If greater than 1 in 150 (5% of pregnancies) then offered testing:
Chorionic Villous Sampling or
Amniocentesis

Question 8

When is CVS done?

Answer 8

Before 15 weeks

placental tissue

Question 9

When is Amniocentesis done?

Answer 9

After 15 weeks

amniotic fluid

Question 10

What will soon be offered if women have greater than 1 in 150 risk?

Answer 10

NON-INVASIVE prenatal testing

• NIPT, DNA fragments in maternal blood

(available privately)