blanch-serum analysis

amniocent

do after 15 weeks
grow cells - karyotype

CVS

10-12 weeks *good 1st tri test*
use trophoblast cells (prob is they have diff karyotypes)

PUBS

rapid fetal karyo,
blood types (rh incomp)
hemo probs
infections
confrims CVS and amnio

ultasound

placenta location
non-invasive
nucal translucency

causes of NT defects

Multi Fact
chrom (13, 18)
low folic acid

to test NT defect

USE AFP week 16 (should be elevated if probs)

things that affect AFP levels

higher in black women
lower in diabetes
lower in heavier women

4 factors to test

AFP
ue3- placenta prod (only during preg)
HCG - placenta prod
Inhibin A - (stops FSH release)

factors in tri 18

all low (don't test inhibin)

factor in tri 21

low AFP & ue3
high HCG and Inhib A

standard of care in US

check for aneupol and NT defects @ 16 week