Prenatal Diagnostic Testing Flashcards
9-14 weeks diagnostic tests to do
Free B-hcG, PAPP-A, nuchal transparency
CVS
B-hcG peaks at 10 wks (100,000 mIU/ml), decreases through 2T, and plateaus in 3T
Fetal Heart Tones at 10-12 wks
Fetal Crown Length via US at 6-12 wks
Abd Circumference, BPD, FL at 13 wks
15-22 wks tests to do
Quad Screen (AFP, B-hcG, Estriol, Inhibin A) Amniocentesis
Quickening by 17-18 wks
18-20 wks tests to do
US for full anatomic screen
24-28 wks tests to do
Gestational Diabetes screen using 1 Hr Glucose Challenge test
28-30 wks tests to do
RhoGAM for Rh(-) women
35-40 wks tests to do
GBS culture
CBC
34-40 wks tests to do
Chlamydia and Gonorrhea culture, HIV, RPR in high risk pts.
When is the gestational sac visible by?
5 wks
hcG levels in early pregnancy double in what time span?
q48hrs
What conditions would cause elevated MSAFP?
Open NTDs Gastroschisis (no peritoneum) Omphalocele Multiple gestation Fetal death Placental abruption
What conditions would cause decreased MSAFP?
Trisomy 18 (Edwards)
Trisomy 21 (Down)
Fetal demise
Inaccurate gestational dating
Quad Screen results of Trisomy 21
Inc B-hcG, Inhibin A
Dec AFP, Estriol
Quad Screen results of Trisomy 18
Decrease AFP, B-hcG, Estriol, Inhibin
Chorionic Villus Sampling
GA?
Disadvantages?
Trans-cervical/abdominal aspiration of placental tissue done at 10-12 wks that is genetically diagnostic
*cannot detect open NTDs, limb defects if done at
Amniocentesis
GA?
Disadvantages?
Transabdominal aspiration of amniotic fluid using US needle at 15-20 wks that is genetically diagnostic and helps determine Lecithin-Sphingomyelin ratio, for women >35 at delivery time,
*PROM, Chorioamnionitis, fetal-maternal hemorrhage, fetal loss
