screening in pregnancy

Question 1

when is diagnostic testing indicated

Answer 1

following prenatal test, if family history

Question 2

when can CVS be performed and what is the advantage

Answer 2

11 weeks- so option of abortion is easier at this stage

Question 3

what is done prior to CVS

Answer 3

ultrasound to confirm pregnancy and location of placenta

Question 4

what are sampled in CVS

Answer 4

trophoblastic cells for karyotype (placenta)

Question 5

how long do results take

Answer 5

2 days for karyotype, 3 weeks for enzyme and gene probe analysis

Question 6

what happens to the genes

Answer 6

PCRd or cultured- culture is more accurate and info on all abnormalities

Question 7

risk of miscarriage in CVS

Answer 7

2-4%

Question 8

how is needle inserted in CVS

Answer 8

transabdominally or transcervically

Question 9

when is amniocentesis performed

Answer 9

15-16 weeks

Question 10

miscarriage amniocentesis

Answer 10

1% (5 if early- 10-13 weeks)

Question 11

what is measures on amniocentesis

Answer 11

Amniotic fluid AFP and cells in fluid are cultured for karyotyping

Question 12

how long does cell culture take in amniocentesis

Answer 12

3 weeks

Question 13

what screening is recommended >20weeks

Answer 13

cordocentesis

Question 14

what are early scans good at looking at

Answer 14

CNS, neck, GI, renal

Question 15

what might fluid accumulation in the neck at 10-14 weeks show

Answer 15

fetal heart failure, anomaly of heart and vesels.

Question 16

what happens to risk of abnormality with greater extent of fetal nuchal translucency

Answer 16

increases

Question 17

what is nuchal translucency screening

Answer 17

used to see who may benefit from more invasive CVS, amnio.

Question 18

other soft markers for downs

Answer 18

fetal nasal bone appearance, Doppler velocity - ductus venosus and tricuspid regurg

Question 19

AFP as a marker

Answer 19

maternal AFP at 17 weeks- in 10% with high AFP there is a fetal malformation. decreased- chromosomal

Question 20

what is the combined test in Downs tests

Answer 20

nuchal translucency, BHCG, PAPP-A (pregnancy associated plasma protein), and womans age

Question 21

what is the integrated test in Downs tests

Answer 21

NT + PAPP-A in first trimester, quadruple test in 2nd trimester

Question 22

what is the quadruple test

Answer 22

maternal AFP + unconjugated estriol + BHCG + inhibin-A + womans age in 2nd trimester

Question 23

when is NT and serum tests done for Downs

Answer 23

11 weeks (10-13+6)