Role Of The Sonogrpaher In OB Flashcards
Sonographer responsibilities…
Recommended requirements for OB exam
Know patients needs and/or physicians to altering exam
Be able to adjust exam based on maternal clinical history
Appropriate scanning techniques so nothing is missed
No personal biases
Sonography in OB…
Primary tool to evaluate fetus Assess deleopment, growth, well being of fetus Indenify problems Prenatal diagnosis of abnormalities Treatment of prenatal abnormalities Parental education and counseling Performed for ONLY valid reasons Accurate, competent, safe, appropriate examination
Indications for 1st trimester OB scan…
Confirm IUP R/o ectopic Define bleeding or pain Confirm gestational age Confirm # of fetuses Confirm cardiac activity Evaluate maternal pelvic pathology Screen for fetal anomalies Evaluate for suspected hydatidform mole
Indications for 2nd/3rd trimester OB scan…
Gestational age, growth, presentation, number Vaginal bleeding/cervical insufficiency Cause of pain Size/date discrepancy Fetal viability PROM/premature labor Placental location Fetal anomalies/abnormal maternal testing Previous complications Poor or no prenatal care
What is CPT?
Current procedural terminology (code-billing)
Identifies type of exam - OB limited, standard, specialized
Nuchal translucency
OB 1st trimester
TV or 3D/4D
Patient history…
Open & closed ended questions LNMP or LMP Gravida, parity Any concerns or problems from the patient or physician Any previous pregnancy problems
Pregnancy dating…
Clinical vs date from previous exam
First day of LNMP
Pregnancy 266 days +/- 10 days
If conception was 14 of 28, from LNMP 280 or 40 weeks
GA assessment not precise
Does not predict EXACT date of labor/birth
If patient unsure of LNMP, ask for EDD from physician
EDD by 1st sonogram (under 20 wks)
Dates established by 1st trimester US-assess growth
Dates MOST ACCURATE in 1st trimester
What does CRL mean?
Crown rump length
Pregnancy is divided into how many trimesters? What are they?
3
1st - up to 13 wks 6 days GA (most accurate time for dating)
2nd - 14 to 26 wks 6 days GA
3rd - 27 wks to term (40 wks)
What is Nagele’s Rule?
EDD = LNMP - 3 months + 7 days
LMP = EDD + 3 months - 7 days
**use pregnancy wheel
Maternal risk factors…
Latex allergy?
Supine hypotension - IVC compression - dizziness
Taking meds
Problems - bleeding, cramps, decreased fetal motion, pain
Previous pregnancy problems
Maternal risk factors for anomalies
Aneuploidy - abnormal # of chromosomes - Downs syndrome
What is nuchal translucency?
Performed on fetuses 11-13 weeks GA
Normal is less than 3 mm
Safety of US…
Aprox 65% of all women have had an OB US
Used since 1950’s w/o side effects
Potential side effects - increased temp, cavitation
Use ALARA - as low as reasonably achieved; control bioeffects
Doppler for an OB patient…
Doppler - higher energy
Maternal & fetal vascular flow, fetal HR, placenta & umbilical cord
Doppler during 1st trimester controversial - use m mode
1st trimester imaging…
TA/TV exam for fetal size, HR, gestational size/contour/appearance
Location of gestational sac
Presence or absence of yolk sac and embryo/irregular masses
Yolk sac confirms IUP - approx 4 mm
Measure CRL for GA
Embryo visualized at 4 weeks
HCG positive at 7-10 days
Placenta thickened along margins
Bowel herniated at 8-10 wks, returns to ABD by 12 wks
Has a cardiac cavity (5 wks & alive)
Faster than maternal HR
Fetal number (embryo + sac)
Assess membrane structure, uterus, adnexa, cul de sac, texture of ovaries/uterus, presence of corpus luteum
MOST RELIABLE IN 1st TRIMESTER
