Fetal Abnormality Screening

Question 1

What are the possible causes of an increased nuchal translucency?

Answer 1

Down syndrome, Edwards syndrome, Turners syndrome, Patau’s syndrome
Congenital heart defects
Abdominal wall defects

Question 2

What is a SIGNIFICANT nuchal translucency finding?

Answer 2

NT greater than or equal to 3.5mm

Question 3

When is a nuchal scan usually performed?

Answer 3

11- 13 weeks 6 days

Question 4

What bio markers are measured in the quadruple test?

Answer 4

Alpha-fetoprotein (AFP)
Oestriol (uE3)
hCG
Inhibin A

Question 5

When is the quadruple test not recommended?

Answer 5

for multiple pregnancies

Question 6

At what time is the quadruple test carried out?

Answer 6

15-18 weeks

Question 7

When is the combined test carried out?

Answer 7

11-14 weeks

If too late, refer for a quadruple test

Question 8

What does an elevated AFP indicate?

Answer 8

Neural tube defect:
Spina bifida
Anencephaly

Question 9

What is the significance of a decreased oestriol level?

Answer 9

Marker for Down syndrome and trisomy 18 (Edward’s)

Question 10

What are the screening tests used for Down syndrome?

Answer 10

Combined and Quadruple test

These give a risk, not a definite diagnosis

Question 11

What diagnostic test can be used to confirm a foetus has Down Syndrome?

Answer 11

Amniocentesis

Question 12

When is amniocentesis offered to those women with an increased risk of birth defects?

Answer 12

15-18 weeks

Question 13

What increased risk factors allow you to have the option of an amniocentesis?

Answer 13

• 35 years or older at time of birth
• screening that showed a defect
• previous children with birth defects
• family history of genetic disorders

Question 14

What does the combined test measure?

Answer 14

Biochemical markers:
PAPP-A
beta - hCG
Ultrasound measurement of crown rump length and nuchal translucency

Question 15

During what time period of the pregnancy is a detailed foetal anomaly scan carried out?

Answer 15

18 - 20 weeks 6 days

Question 16

What is the purpose of the early pregnancy scan?

Answer 16

Detect gestational age
Detect multiple pregnancies
Take measurements required for the Down Syndrome screening programme

Question 17

What diseases are tested for at the booking blood test?

Answer 17

Sickle cell disease
Thalassaemia 
Congenital infections:
Syphillis
Hepatitis B
HIV

Question 18

What are the lab findings of biochemical markers when a women is pregnant with a child who has Down Syndrome?

Answer 18

Elevated hCG and INH-A
Lower than average levels of uE3 and AFP

Combined - low PAPP-A

Question 19

When can chorionic villus sampling be performed from?

Answer 19

From 9 weeks into the pregnancy (earlier than an amniocentesis which is performed at 15-18weeks)

Question 20

What is the risk of spontaneous miscarriage in chorionic villus sampling?

Answer 20

0.5 - 2%

Question 21

What is the risk of infection and spontaneous miscarriage in an amniocentesis?

Answer 21

1%

Question 22

What is the next generation of diagnostic testing?

Answer 22

NIFTY

Examines peripheral blood from the mother to estimate the risk of foetal chromosomal aneuploidies carried in the newborn

Question 23

When does the early pregnancy scan occur?

Answer 23

10-12 weeks