Congenital Abnormalities

Question 1

what % of pregnancies have a congenital abnormality

Answer 1

2%

Question 2

What are the common causes of congenital abnormalities

Answer 2

Chromosomal abnormalities

Structural defects (CDH)

Congenital infection (rubella)

Drugs (anti-epileptics)

Inherited disease (CF)

Question 3

what are the methods of testing for congenital abnormalities

Answer 3

Maternal Blood tests

Non-invasive Foeta DNA

USS

Foetal MRI

3D/4D USS

Amniocentesis

Chorionic Villus sampling

Preimplantation Genetic Diagnosis

Question 4

what are some common maternal blood tests when testing for congenital abnormalities during pregnancy

Answer 4

Pregnancy associated protein A

BHCG

Alpha fetoprotein

Oestrodiol

Inhibin A

Question 5

what can amniotic fluid sampling detect

Answer 5

Chromosomal abnormalities

Some maternal infections (Toxoplasmosis ,CMV )

Inherited Disorders (CF, Sickle cell, Thalassaemia)

Question 6

what is the risk of miscarriage after an amniocentesis

Answer 6

1%

Question 7

when is it safest to perform an amniocentesis

Answer 7

15 weeks

Question 8

why would you do a chorionic villus sample over an amniocentesis

Answer 8

it can be done earlier (11 weeks)

Question 9

what are the components for the combined test for chromosomal anomalies?

Answer 9

PAPP-A
BHCG
 maternal age 
nuchal translucency at dating scan,
tricuspid regurgitation
nasal bone presence

Question 10

what is the quadruple test and when is it done in antenatal care

Answer 10

Quadruple test is used if the booking for the pregnancy is too late for a booking scan, or if the nuchal translucency isn’t possible to get (BMI)

It instead quantifies risk based on maternal blood tests, measuring the levels of BHCG, AFP, inhibin and oestriol