2.4 Antenatal and Postnatal Screening Flashcards
What does antenatal screening identify?
Identifies the risk of a disorder so that further tests and prenatal diagnosis can be offered
What are the two Ultrasound Imaging scans?
- Dating Scans (12-14 weeks)
- Anomaly Scans (18-20 weeks)
What does a dating scan do?
- Determined pregnancy state and due date
- Used with tests for marker chemicals which vary normally during pregnancy
What is anomaly scans used for?
To detect serious physical abnormalities in the fetus
What are blood and urine tests carried out for?
To monitor the concentrations of marker chemicals
What could be the result of measuring a chemical at the wrong time?
False positive result
What can an atypical concentration lead to?
Diagnostic testing to determine if the fetus had a medical condition
What is diagnostic testing used for?
To confirm a chromosomal or gene abnormality of the fetus
What is a karotype?
A profile of all the chromosomes arranged into their homologous pairs from one organism
What are the two types of diagnostic testing?
- Amniocentesis
- Chorionic Villus Sampling (CVS)
What are amniocentesis factors?
- A sample of foetal cells taken from the amniotic fluid
- Risk of miscarriage
- Lower risk than CVS
What are the factors of CVS?
- A sample of cells are taken from the placenta
- Risk of miscarriage
- Can diagnose earlier compared to amniocentesis
What is autosomal recessive?
- Rare
- May skip generations
What is autosomal dominant?
- Appears in every generation
- Affected parent
- Males and females express trait equally
What is autosomal incomplete dominance?
- Fully expressed form of disorder occurs rarely
- Males and females equally
