Antenatal Screening

Question 1

What is the purpose of antenatal screening? (2)

Answer 1

Detect risk of disorders such as Down’s syndrome, cystic fibrosis, muscular dystrophy
Determine sex of baby

Question 2

Example of antenatal tests

Answer 2

Ultra sound
Rhesus antibody testing
Amniocentesis
Chronic villus sampling

Question 3

Two stages of ultrasound

Answer 3

1- dating scan (8-14 weeks)
-determine age and due date

2- anomaly scan (18-20 weeks)
- physical developments

Question 4

Biochemical tests

Answer 4

Detects marker chemicals produced during physiological changes of pregnancy

Question 5

Amniocentesis weeks

Answer 5

15th-18th week

Question 6

Amniocentesis advantages

Answer 6

Prenatal diagnosis

Detects neural tube defects

Question 7

Amniocentesis disadvantages

Answer 7

Small miscarriage risk

Gives later results

Question 8

Chronic villus sampling weeks

Answer 8

11th-14th week

Question 9

Chronic villus sampling advantages

Answer 9

Prenatal diagnosis

Earlier results

Question 10

Chronic villus sampling disadvantages

Answer 10

Not detect newest tube defect
Small miscarriage risk
Carry risk of defects to fingers and toes if carried out too early

Question 11

Karyotype

Answer 11

Image of chromosomes
Arranged in homologous pairs
Used to identify anomalies in structure and numbers of proteins

Question 12

Rhesus anti body testing blood types

Answer 12

Mother is negative

Get us is positive

Question 13

What happens in rhesus

Answer 13

• Fetus red blood cells cross the placenta
• This trigger the release of mothers antibodies
• antibodies can cross into feral blood & cause blood clot

Question 14

Rhesus antibody treatment

Answer 14

•given Anti rhesus antibodies after 1st pregnancy - so that rhesus positive blood cells are destroyed before discovered by mothers immune
-protects from rhesus negative baby