Role of sonography in OB Flashcards
How is sonography used in OB?
to assess development, growth an well being of the fetus
What is the primary tool to evaluate the fetus?
sonography
What is the role of obstetric management?
it is altered to provide best care when sonography identifies problems
If conception is on day 14 (of 28 day cycle) what is the pregnancy duration?
from LNMP is 280 days or 40 weeks
how do you determine clinical dates?
first day of LNMP
What do you ask if patient is unsure of LNMP?
ask due date physician gave EDD
What is EDC?
estimated date of conception
The EDD is most accurate in what trimester?
first…under 20 weeks
Dates established by 1st trimester US should not be changed,when?
on consecutive US that assess growth
how are the three trimesters broken up?
first: up to 13 weeks 6 days gestational age (most accurate time for dating pregnancy by ultrasound
FINISH slide 10
what is nagele’s rule?
a way to figure out the EDD
EDD = LNMP-3months + 7 days
LMP = EDD + 3 months - days
In first trimester when might you use doppler?
Only to determine fetal demise
error on the side of being safe and don’t use doppler unless you absolutely must when the benefit out weighs the risk
What is the main reason for first trimester fetal scan?
viability
Cardiac motion usually seen when embryo is _______mm or larger?
5
5 and ALIVE*
polyhydrominos, oligohydrominos
know these!!
