2.7 - Testing for CF Flashcards
What is Amniocentesis?
A needle is used to collect amniotic fluid containing the babies cells.This happens around 16 weeks of pregnancy.
What are the advantages and disadvantages of Amniocentesis?
Advantages - Low risk of misscariage and fairly cheap
Disadvantages - Still a risk of misscariage.Happens later in pregnancy.5% risk of false positive.Results take time
What is CVS?
A needle is interested via the cervix towards the placenta.Here a sample of placental tissue is collected.
What are the advantages and disadvantages of CVS?
Advantages - Fairly cheap,quickly available and a low chance of a false positive
Disadvantages - 2/100 (2%) chance of miscarriage
What is NIPD?
Analyzing fragments of DNA found in the mothers blood.
What are the advantages and disadvantages of NIPD?
Advantages - Very cheap,happens early on (7-9 weeks),only requires a sample of blood,no risk of miscariage,results come back quick (2 weeks) and chance of false positive is 1%
Disadvantages - Only available for some couples and only used for a small number of genetic disorders
What is PGD?
When The embryo is tested at 4-8 cell stages and is tested for the presence of various genes.
What are the advantages and disadvantages of PGD?
Advantages - Don’t have to be pregnant (happens outside the body)
Disadvantages - Only used for IVF patients,very expensive (£6000),ethically wrong ,16% chance of a false positive , emotionally traumatic and only 30% chance success rate
What is a false positive?
The test says the baby has a genetic disease when actually it is healthy
What is a false negative?
The test says the baby is healthy but there is actually a problem
What does invasive mean?
When a medical test inserts something into the body
