Down's Syndrome and screening Flashcards
1
Q
epidemiology?
A
incidence increases w increasing maternal age
2
Q
pathology?
A
trisomy 21- commonly caused by non-dysunction at meiosis
3
Q
who is offered screening?
A
all women- purpose is to decide which women need more invasive tests to confirm diagnosis
4
Q
outline the screening tests for Down’s Syndrome (table)
A
5
Q
following screening - what next?
A
screening tests put together provide a risk score- if risk greater than 1/150–> woman offered amniocentesis or chorionic villus sampling
6
Q
what does CVS / amniocentesis allow?
A
a sample of foetus’ cells to be sent for karyotype
7
Q
difference between CVS and amniocentesis?
A
- CVS
- US guided biopsy of placental tissue
- used <15 weeks
- amniocentesis
- US guided aspiration of amniotic fluid
- used later in pregnancy
