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Flashcards in OB Lab Tests Deck (15)
0

Having a 5.0MOM (measures of the mean) in AFP can be a strong indication for what abnormality

Omphalocele

1

Triple Screen

HCG estriol AFP

Trisomy 21: dec AFP & estriol, inc HCG
Trisomy 18: dec AFP, estriol, & HCG

2

Quad Screen

HCG estriol AFP inhibin A

Inc Down syndrome detection.

3

Nuchal Lucency

< 3 mm normal
> or = abnl

Assoc with chromosomal anomalies, cardiac anomalies, poor fetal growth, preg fail.

11-14 weeks GA
Use + calipers
Fetus mid sag plane. No hyper extension or hyper flexion of neck. Amnion must be separate.

4

MSAFP

Asses neural tube defects. Also asses abd wall defects, ABS, cystic hygromas, teratoma, renal abnl, GI obstruct, & placenta aberrations

15-20 wks
AFP produced in fetal liver

Inc with maternal liver disease, twins, fetal death, twins, misdated pg, norm

Dec with trisomies, no pg, molar pg, fetal death, misdated pg, norm

5

Genetic testing

23 pairs of chromosomes. 22 + xx or xy

Stained DNA

6

Chorionic Villi Sampling

9-12 weeks
Samples placenta
Diagnostic

7

Amniocentesis

14 wks
Samples amniotic fluid once amnion is fused.
Diagnostic

8

Fluorescence In Situ Hybridization FISH

Fast results 24 hrs
Tri 21 13 18 22

9

Lecithin/Spingomyelin Ratio

Steroid injected into lungs to see if mature
> 2.1 = normal

Maturity may be delayed with diabetes and accelerated with severe diabetes & chronic HTN

10

HCG

Inc highly with molar pregnancy
Inc with twins
Dec with ectopic

Doubles every 2 days

11

Cell Free DNA

Extremely accurate but not diagnostic. Detects tri 13, 18, 21
Non invasive

12

HCG for sac seen TA & TV

TA: 1800mIU/ml
TV: 500mlU/ml

HCG should double every 2 days

13

Mosaisism

Norm and abnl collection in placenta in CVS. Placenta cells may not always be the same as fetal cells.

14

2.5 MOM of MSAFP is

Normal