Week 3- antenatal screening and care

Question 1

What are the principles of antenatal screening?

Answer 1

Detect and manage pre-existing maternal disorders that may affect the pregnancy outcome.
Prevent or detect and manage maternal complications of pregnancy.
Prevent or detect and manage fetal complications of pregnancy.
Detect congenital abnormalities
Plan circumstances of birth to ensure maximum safety.
Provide advice regarding lifestyle.

Question 2

How many antenatal appointments will a patient have?

Answer 2

Up to 10 in a first pregnancy.

Around 7 if you’ve previously had a child.

Question 3

What will occur in your first antenatal appointment?

Answer 3

History- including menstrual, medical, obstetric, family and social
Examination- height, weight, bp, cardiovascular, abdomen.

Question 4

What other specific tests are done on the booking visit?

Answer 4

Haemoglobin
Blood type- (ABO, rhesus)
Syphillis, rubella, HIV, Hep B and C
Urinalysis 
Ultrasound- to confirm viability, number of foetus's, confirm gestation.

Question 5

In the follow up visits to the antenatal clinic, what do they consist of?

Answer 5

History- physical and mental health. Foetal movements?
Examination- BP and Urinalysis
-Symphysis to fundal height
-Lie and presentation
-Engagement of presenting part
-Feotal heart auscultation

Question 6

What screening tools are used to identify foetal anomalies?

Answer 6

Ultrasound

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Question 7

The risk of having a baby born with down syndrome increases with the age of the mother. True or false?

Answer 7

True.

Question 8

In the first trimester, what tests can be done to look for early signs of down syndrome? At what gestation are they done? What are they combined with?

Answer 8

Nuchal thickness- measures skin thickness behind the foetal neck in ultrasound.
Done from 11-13 +6 weeks.
Combined with HCG and PAPPA (pregnancy associated plasma protein A).

Question 9

In the second trimester, what tests can be done to look for downs syndrome? What gestation are these tests done at?

Answer 9

Blood sample at 15-20 weeks.

Assay of HCG and AFP.

Question 10

How is maternal risk calculated (downs syndrome) in the first and second trimester?

Answer 10

All test results are combined with the maternal age of the mother to come up with a risk score.
>1:250 is high risk. This requires further investigation.

Question 11

Does a low risk score in Down syndrome screening exclude Down syndrome?

Answer 11

No

Question 12

What are the specific diagnostic tests that can be used to detect downs syndrome once you’ve been identified as being at risk? When can these tests be done? Are there any associated risks?

Answer 12

Amniocentesis-usually performed after 15 weeks.
Carries a miscarriage rate of 1%

Chorionic villus sampling- usually performed after 12 weeks. 2% risk of miscarriage.