8.4 Down's Screening Flashcards
When is the combined test for trisomy 21 done?
COMBINED TEST 11-14 weeks US and blood
What is measured to show increased risk of Downs in the Combined Test?
- Nuchal translucency over 6mm
- increased BETA-HCG
- decreased PAPPA (pregnancy associated plasma protein A)
(COMBINED TEST 11-14 weeks US and blood)
When is the triple test for Downs done?
TRIPLE TEST 14-20weeks, blood only
What is measured to show increased risk of Downs in the Triple Test?
- increased BETA-HCG
- decreased AFP
- decreased SERUM OESTRIOL
(TRIPLE TEST 14-20weeks, blood only)
When is the quadruple test for Downs done?
QUADRUPLE TEST 14 -20 weeks, same as triple but with an extra blood test
What is measured to show increased risk of Downs in the Quadruple Test?
- increased BETA-HCG
- decreased AFP
- decreased SERUM OESTRIOL
plus:
- risk increased with INHIBIN-A
After the combined, triple or quadruple test what is done?
Tests give Risk Score;
If greater than 1 in 150 (5% of pregnancies) then offered testing:
Chorionic Villous Sampling or
Amniocentesis
When is CVS done?
Before 15 weeks
placental tissue
When is Amniocentesis done?
After 15 weeks
amniotic fluid
What will soon be offered if women have greater than 1 in 150 risk?
NON-INVASIVE prenatal testing
- NIPT, DNA fragments in maternal blood
(available privately)
