Antenatal screening

Question 1

Define screening

Answer 1

A process of identifying apparently healthy people who may be at increased risk of a disease or a condition

Question 2

What are the benefits of screening?

Answer 2

• Identify high risk group for diagnostic testing
• Counsel about risk of disease being present
• Offer treatment for prevention

Question 3

What are the downsides to screening?

Answer 3

• False positives
• Harm from screening or further testing
• Cost-from screening,diagnosis,treatment

Question 4

What disease characteristics are required for a screening test to be developed for a disease?

Answer 4

• must be an important health problem
• must have a recognizable early or latent phase
• acceptable treatment for disease or condition exists

Question 5

What test characteristics are required for the screening test|?

Answer 5

• Valid&reliable
• Acceptable to population
• Cost is proportionate to medical care as a whole

Question 6

Outline screening for sickle cell& thalassaemia:

1. ) who gets screened
2. ) when does screening happen?
3. ) How is screening performed?

Answer 6

1.)High incidence: all pregnant women
Low incidence: based on ethnic origin
2.)pre-conception to 10 weeks
3.) Blood test

Question 7

Outline screening for Infectious disease:

1. ) who gets screened
2. ) What gets screened for ?
3. ) when does screening happen?
4. ) How is screening performed?

Answer 7

1. )Offered to all women
2. ) HIV, hep B, syphillis
3. ) at the booking
4. ) Serology

Question 8

Outline screening for Chromosomal abnormalities:

1. ) who gets screened
2. ) when does screening happen?
3. ) How is screening performed?

Answer 8

1. ) offered to all pregnant women
2. ) between 11(+0) - 13(+6) weeks gestation by ultrasound
3. ) -Combined test
   - Fetal nuchal translucency
   - Maternal serum BetaHCG
   - Maternal serum PAPP-A

Question 9

How do we screen for downsyndrome?

Answer 9

Fetal nuchal translucency

• The normal babies had a thin back of neck
• Those affected by down-syndrome had a really thick back of the neck

Question 10

Compared and contrast the different trisomy markers

Answer 10

T21: 
-Nuchal translucency= big increase
-Beta-hCG= slightly increased
-PAPP-A= slightly decreased
T18:
-Nuchal translucency= big increase
-Beta-hCG= big decrease
-PAPP-A=big decrease
T13: 
-Nuchal translucency= slightly increased
-Beta-HCG= slightly decreased
-PAPP-A=big decrease

Question 11

What is acrania ?

Answer 11

-Malformation of the babies head
-No brain tissue or ossified skull
-Lethal within 1st week of life
ultrasound diagnosis:
-12 weeks: absence of ossified skull
-16 weeks anencephaly

Question 12

Outline screening for fetal anomalies:

1. ) who gets screened
2. ) when does screening happen?
3. ) How is screening performed?

Answer 12

1. ) all pregnant women are offered
2. )Between 18-22 weeks
   - earlier detection becoming more common

Question 13

List some fetal abnormalities

Answer 13

• spina bifida
• diaphragmatic hernia
• cleft lip & palate
• Alobar holopresencephaly: when there is a complete failure of the brain to divide into right and left hemispheres which results in the loss of mid-line structures of the brain and face as well as fusion of the cavities of the brain, known as lateral ventricles and the third ventricle (which are normally separated).

Question 14

What are the high risk factors for pre-eclampsia?

Answer 14

• Hypertensive disease in a previous pregnancy
• Chronic renal disease
• Chronic hypertension
• Diabetes mellitus
• Autoimmune disease such as SLE or APS

Question 15

What are the moderate risk factors for pre-eclampsia?

Answer 15

• 1st pregnancy
• age>/=40yrs
• BMI>/= 35kg/m^2
• Inter-pregnancy interval>10 yrs
• family history of pre-eclampsia

Question 16

What kind of scenarios indicate a women high-risk of pre-eclampsia & in need of aspirin

Answer 16

• pre-eclampsia in >/= 2 previous pregnancies

- pre-eclampsia <34 weeks in previous pregnancy