1st Tri Flashcards
Gestational age:
conceptual + 2 wks
What’s the first sonographic sign of an intrauterine pregnancy?
gestational sac (4.5wks)
What is the double decidual sac sign made up of?
chorion + decidua capsularis
These MSD measurements should be made at the:
interface between the echogenic border and fluid
Normal first trimester GS growth rate should be:
1mm/day
An intrauterine pregnancy should be seen TV with a serum beta hCG level greater than
1000-2000mIU/mL
What are causes of a high AFP level?
underestimated gestational age multiple gestations open NTD abdo wall defect cystic hygroma renal anomalies fetal demise
What are causes of a low AFP level?
overestimated gestational age chromosomal abnormalities trophoblastic disease long-standing fetal demise chronic maternal hypertension diabetes
With TVS we should see the GS
<8mm at around 5-5.5wks
The yolk sac and embryo can be seen separated by the ______ but connected by the __________ _______
amnion, vitelline duct
The yolk sac measures ______ to ______ in the first trimester
2-6mm (inner borders)
The embryo grows at a rate of _______ .
1mm/day
When is the embryonic period?
wk 6-10
When can we see cardiac activity?
5-5.5 wks or when the CRL=5mm
With a TA technique, we should see the embryo at what measurement?
25mm
What is the normal heart rate of the embryo?
120-180bpm
The earliest ultrasound with a crown rump length equivalent to at least 7 weeks (or 10 mm) should be used to determine the gestational age. True or false
True
By what weeks can getting the CRL be difficult? Why? (idk if this is something we need to know but)
11-12wks bc of fetal flexion
A thickened NT is associated with? (4)
tri21
adverse outcome
genetic syndromes
structural anomalies
The NT must be evaluated with a CRL no less than and no more than?
45-84mm
What GA do we take a NT measurement?
11+0 - 13+6wks
