Prenatal Screening Flashcards
(40 cards)
What does screening do?
Identifies apparently healthy people who may be at an increased risk of a disease or condition
What does screening do?
Identifies apparently healthy people who may be at an increased risk of a disease or condition
What is the benefit of screening people?
Allows for earlier treatment and allows informed decisions to be made.
When is the early pregnancy scan done?
10-14 weeks
What proportion of due dates are put back after an early pregnancy scan is done?
1 in 5
What can an early pregnancy scan detect?
- Multiple pregnancies and chronicity
- Due date
- Structural abnormalities
What are some examples of structural abnormalities that can be detected in an early pregnancy test?
- Spina bifida
- Anencephaly
- Bladder outflow obstruction
What are the three trisomies?
- Trisomy 13 = Patau’s
- Trisomy 18 = Edward’s
- Trisomy 21 = Down’s
What is the difference between Chronic Villus Sampling and amniocentesis?
- CVS samples part of the placenta (attached to the uterus)
- Amniocentesis samples some of the amniotic fluid
What is the risk of miscarriage in CVS and amniocentesis?
1%
When can CVS and amniocentesis be done?
CVS at 11+ weeks
Amniocentesis at 16+ weeks
What can increase the risk of miscarriage in CVS / amniocentesis?
Twin pregnancies
What does the first trimester screening test combine to work out the chance of a baby having trisomy?
- Age
- Nuchal translucency measurements from ultrasound
- Blood test
What does the blood test done for the first trimester screening test measure?
PAPP-A and B-hCG
What is PAPP-A?
Pregnancy associated plasma protein-A and it has low levels in pregnancies with Down’s syndrome
What is B-hCG?
Beta human chorionic gonadotrophin and its levels are high in pregnancies with Down’s syndrome
When is the quadruple test done?
14+2 weeks to 20 weeks
What does the quadruple test measure the levels of?
- UE3 (low in Down’s)
- AFP (low in Down’s)
- Inhibit A (high in Down’s)
- B-hCG (high in Down’s)
What does NIPT stand for and what is it?
Non-Invasive Prenatal Test
Screens blood and can identify risk of trisomy
What are the advantages of NIPT?
- High detection rates
- Means less invasive diagnostic tests are done
- Further option for women
What are the disadvantages of NIPT?
- Screening test so isn’t diagnostic
- Positive result is confirmed with an invasive test afterwards
What is the benefit of screening people?
Allows for earlier treatment and allows informed decisions to be made.
When is the early pregnancy scan done?
10-14 weeks
What proportion of due dates are put back after an early pregnancy scan is done?
1 in 5
