Prenatal Screening

Question 1

1st TM prenatal screening

Answer 1

age risk + analyte testing (PAPP-A and free beta-HCG) + nuchal translucency (+/- nasal bone)

Question 2

PAPP-A

Answer 2

pregnancy assoc plasma protein A

lower in aneuploid pregnancies

Question 3

betaHCG findings in prenatal screening

Answer 3

hi in trisomy 21

low in trisomy 18 and 13

Question 4

2nd TM prenatal screening

Answer 4

If 1st TM screen was done:
no quad screen, just do AFP to screen for neural tube defects

Else:
Quad screen (serum markers) - AFP, hCG, unconjugated estriol (uE3), inhibin A (DIA)

Question 5

AFP as prenantal marker

Answer 5

low in down syndrome, high in NT defects (but there is some overlap!)

Question 6

what type of genetic problems do advanced maternal vs paternal age cause?

Answer 6

maternal age > more meiotic 1 nondisjunction errors > aneuploidy
paternal age > more replication errors > new mutation AD d/o

Question 7

what are the implications of finding confined placental mosaicism in chorionic villi sampling?

Answer 7

indicates that there is a risk for uniparental disomy via trisomy rescue, should recommend an amnio to tell what the fetus actually has

Question 8

assisted reproductive technology carries risk of what d/o?

Answer 8

epigenetic d/o - methylation, imprinting

ex Beckwith Weidman syndrome, angelman syndrome