Ante and post natal care Flashcards
what is ante and post natal care
Antenatal and postnatal screening is when a variety of techniques are used to monitor the health of the mother, developing foetus and baby.
Antenatal screening identifies the risk of a disorder so that further tests and a prenatal diagnosis can be offered.
describe the ultrasound screens
Dating scan
takes place between 8 and 14 weeks. It determines the stage of pregnancy and due date. This is used with tests for marker chemicals which vary normally during pregnancy.
• Anomaly scan takes place between 18-20 weeks and may detect serious physical abnormalities in the foetus.
describe blood and urine tests
Routine blood and urine tests are carried out to monitor the concentrations of marker chemicals.
Measuring a chemical at the wrong time could lead to a false positive result.
An atypical chemical concentration can lead to further diagnostic testing to determine if the foetus has a medical condition.
describe amniocentesis
Amniocentesis is a procedure is usually carried out between the 15th and 20th week of pregnancy which involves the collection of foetal cells contained within amniotic fluid.
A needle is inserted through the abdomen/uterus wall into the amniotic sac and a sample of the amniotic fluid is collected.
• Advantage - it is used to detect genetic or chromosomal abnormalities of the foetus.
• Disadvantage - the procedure carries a risk of miscarriage.
describe CVS
Chorionic villus sampling is procedure usually carried out between the 11th and 14th week of pregnancy.
This procedure removes a small sample of cells from the placenta.
These can be obtained through the abdomen or through the cervix.
• Advantage - it is used to detect genetic or chromosomal abnormalities of the foetus and can be performed earlier than an amniocentesis.
• Disadvantage - the procedure carries a higher risk of miscarriage than an amniocentesis.
describe diagnostic testing
Diagnostic testing - cells from samples are cultured to obtain sufficient cells to produce a karyotype to diagnose a range of conditions.
A karyotype shows an individual’s chromosomes arranged as homologous pairs
In deciding to proceed with these tests, the element of risk will be assessed, as will the decisions the individuals concerned with the likely to make if a test is positive.
describe autosomal recessive disorders
In autosomal recessive disorders are expressed very rarely and often skip generations and it affects both males and females equally.
describe autosomal dominant
In autosomal dominant disorders, affected individuals will always have an affected parent, it affects both males and females equally. When the trait does not appear in a branch it won’t appear in future generations.
describe incomplete dominance
With incomplete dominance disorders carriers of the allele show a rmild form or intermediate form of the trait, as neither allele is completely dominant over the other.
describe sex linked recessive single gene disorders
Occurs on the X chromosome. Sex linked recessive disorders always have more males affected than females. None of the sons of affected males are affected, however grandsons of affected males can show the trait.
describe PKU
Phenylketonuria is caused by a substitution mutation meaning that an enzyme which converts phenylalanine to tyrosine is non-functional.
• Individuals with high levels of phenylalanine are placed on a restricted diet.
Postnatal diagnostic test for PKU
• The postnatal diagnostic test for PKU is the Guthrie test, also known as the heel prick test.
• The heels of new-born babies are pricked, and samples of blood are pressed onto the test card and analysed for levels of phenylalanine.
