Flashcards in Ante and postnatal screening Deck (44)
What does antenatal and postnatal screening involve?
Testing for diseases or conditions in a fetus or embryo before it is born
What does antenatal screening identify?
The risk of a disorder so that further tests and a prenatal diagnosis can be offered
What do common antenatal testing procedures include?
ultrasound scanning, amniocentesis, chorionic villus sampling (CVS) and rhesus antibody testing
What are three uses of an ultrasound used to produce?
An ultrasound image on a computer screen ,gestational dating scan and anomaly scan
What is a gestational dating scan mean?
which is used to determine the stage of pregnancy and date that the baby is due
What is an anomaly scan?
Used to detect the presence of serious physical problems in the fetus
What is an ultrasound?
image on a computer screen
Why are biochemical tests carried out?
To detect marker chemicals that are produced during normal physiological changes that take place during pregnancy
What is a screening procedure?
Tests such as ultrasound imaging that indicates the possible presence of a disorder
What can diagnostic tests like amniocentesis and CVS confirm?
The presence of conditions such as down syndrome
What can cells from amniocentesis and CVS do?
Be cultured to obtain sufficient cells to produce karyotype
What is karyotype?
An image of an individual's chromosomes arranged in homologous pairs
Why is a karyotype used?
To identify anomalies in the number or structure of chromosomes
What are problems with diagnostic test like amniocentesis and CVS?
THey are invasive and carry a small risk of inducing miscarriage
When can CVS be carried out?
Before amniocentesis but has a higher risk of inducing miscarriage
Why is Rhesus antibody carried out earlier in a pregnancy?
To determine the rhesus status of the mother, to ensure that she shows no immune responses to her fetus
what complications can event of a second pregnancy
If a mother is rhesus negative and the fetus is rhesus positive
What is given to negative rhesus mothers after sensitising events such as the birth of a baby?
Anti rhesus antibodies
What does postnatal screening involve?
Health checks that are carried out after the birth of the baby. These are aimed at detecting certain conditions or abnormalities
What is postnatal testing used to detect?
Metabolic disorders such as phenylketonuria (PKU)
What is PKU?
An inborn error of metabolism
How is PKU caused?
By an autosomal recessive genetic disorder
What can individuals with PKU cannot do?
Metabolise excess phenylalanine
What can happen if PKU is not detected soon after birth?
The baby's mental development can be affected
What do people with PKU have to do?
Be placed on a restricted diet that lacks the amino acid phenylalanine
What are pedigree charts compiled and used to analyse?
Patterns of inheritance in genetic screening and counselling
What are pedigree charts constructed to do?
Provide information and advice in situations where there is the possibility of passing on a genetic disorder to potential offspring
What are pedigree charts compiled to do?
To analyse patterns of inheritance in genetic screening and counselling
In what situation are pedigree charts used to provide information and advice?
Where there is a possibility of passing on a genetic disorder to potential offspring