Prenatal diagnostic testing

Question 1

Which 4 elements are tested in quad screening?

Answer 1

MSAFP, Inhibin A, Estriol, B-hCG

Question 2

Elevated MSAFP (>2.5 MoMs) is associated with

Answer 2

Open neural tube defects, abdominal wall defects, multiple gestation, incorrect gestational dating, fetal death, placental abnormalities

Question 3

Reduced MSAFP (<0.5 MoM) is associated with

Answer 3

Trisomy 21 and 18, fetal demise, inaccurate gestational dating

Question 4

When is Pregnancy Associated Plasma Protein A recommended?

Answer 4

Weeks 9-14. Its available earlier than chorionic villus sampling and also less invasive. Its a screen of low risk pregnant women (<35 y.o.)

Question 5

MSAFP, Estriol, Inhibin A, and B-hCG in Trisomy 18

Answer 5

All decreased.

Question 6

MSAFP, Estriol, Inhibin A, and B-hCG in Trisomy 21

Answer 6

Decreased AFP, Decreased estriol, Increased B-hCG, increased Inhibin A

Question 7

When is CVS available?

Answer 7

10-12 weeks

Question 8

Disadvantages of CVS

Answer 8

Risk of fetal loss is 1%. Cannot detect open neural tube defects. Limb defects associated if <9 weeks.

Question 9

Disadvantages of amniocentesis

Answer 9

PROm, chorioamnionitis, fetal-maternal hemorrhage

Question 10

When can amniocentesis be performed?

Answer 10

15-20 weeks.