Fetal Imaging

Question 1

if you can only request for one uts throughout pregnancy, do it at ____ weeks

Answer 1

18-20 weeks

Question 2

clinical use of first trimester uts

Answer 2

fetal age
cardiac activity
fetal number and chorionicity/amnionicity
fetal abnormalities (nt, anencephaly, ventral wall defects)

Question 3

what do you see when aging fetus

Answer 3

5 weeks: gestational sac
5.5 weeks: gs + yolk sac
6 wks: gs + ys + embryo + cardiac activity

Question 4

most accurate method to get aog

Answer 4

crown rump length

Question 5

indications for first trimester uts

Answer 5

• chorionic villus sampling, embryo transfer, localization, removal of iud
• assess for fetal anomalies
• evaluate maternal pelvic masses and/or uterine abnormalities
• measure nuchal translucency for fetal aneuploidy
• evaluate suspected gestational trophoblastic disease

Question 6

when to measure nuchal translucency

Answer 6

11-14 wks aog

Question 7

t/f decreased nt in the first trimester may be associated with chd in the second trimester

Answer 7

false, INCREASED NT

trisomy 21 or 18

Question 8

sign for anencephaly in uts

Answer 8

“frog’s sign”

Question 9

ventral wall defects

Answer 9

omphalocoele and gastroschisis

Question 10

t/f if the patient is suffering for pain or bleeding, do not wait for 11-14 wks for an uts

Answer 10

true

Question 11

three types of uts in second and third tri

Answer 11

standard
specialized (congenital anomaly, doppler velocimetry, fetal echocardiography)
limited exam (fetal presentation, amniotic fluid, placental localization, fetal gender)

Question 12

clinical use of uts in 2nd and 3rd trimesters

Answer 12

accurate determination of fetal age
fetal number
cardiac activity
placental localization
diagnosis of major anomalies
fetal weight estimation

Question 13

methods for fetal aging in second trimester

Answer 13

biparietal diameter
head circumference
fetal abdominal circumference
femur length

Question 14

margin of errors in fetal aging via bpd

Answer 14

12-18 wks aog, ~1 wk
2nd t: 2 wks
3rd t: 3 wks

(similar to hc)

Question 15

purpose of ac

Answer 15

reflects how thin baby is

done when searching for iugr

Question 16

purpose of fl

Answer 16

most accurate measurement in intrauterine fetal demise

Question 17

uts can be accurate for fetal imaging until __ weeks

Answer 17

24 weeks with error of 1-2 weeks

Question 18

t/f the second trimester scan is when fetal presentation is best seen

Answer 18

false, third trimester in order to plan for delivery

Question 19

how to measure amniotic fluid volume

Answer 19

single deepest pocket: 2-8 cm

amniotic fluid index: 5-24 cm

Question 20

how to measure fetal weight

Answer 20

biparietal diameter, head circumference, abdominal circumference, femoral length

Question 21

components of standard fetal anatomical survery

Answer 21

head, face, neck
chest and heart
abdomen
spine and extremities
fetal gender

Question 22

when to do biophysical profile

Answer 22

at term or 28 wks if there are indications

Question 23

what is tested in biophysical profile

Answer 23

fetal movement
fetal tone (flexion/extension)
fetal breathing (abdomen)
amniotic fluid
non-stress test

Question 24

indications for congenital anomaly scan

Answer 24

• maternal age >35
• previous child with congenital anomaly
• fhx of congenital anomaly
• exposure to radiation or teratogen
• iddm
• repeated pregnancy loss
• severe oligo or polyhydramnios
• iugr
• abnormal placenta
• suspicious findings (enlarged heart)

Question 25

notable abnormalities that can be visualized in uts

Answer 25

anencephaly
ventriculomegaly
cleft lip
vsd
extremities

Question 26

use of doppler velocimetry

Answer 26

iugr and preeclampsia