First Trimester Abnormal: Ectopic Pregnancies Flashcards
three things we check for in first trimester scan
- mean sac diameter
- crown rump length
- nuchal
MSD
mean sac diameter
CRL
crown rump length
when is MSD measured
when the embryo is identified
when can the double decidual reaction be seen
starting at 4-5 weeks
mean sac diameter formula
(lenght x width x height)/3
endovaginal scan MSD size when yolk sac seen vs when embryo seen
8mm
vs
16mm
transabdominal scan MSD size when yolk sac seen vs when embryo seen
20mm
vs
25mm
GS grows how much every day
1.1mm
what is the purpose of comparing MSD to embryo
for early diagnosis of oligohydramnios (low fluid)
from 5.5-9 weeks, if the MSD - CRL is less than _____, oligohydramnios is suspected
5mm
CRL is used between ___ and ___ weeks
6
13
what is the most accurate measurement to predict gestational age and how many days off may it be
CRL
+/- 3 days
PUL
pregnancy of unknown location
three main differential diagnoses when b-HCG is positive but no pregnancy seen on US
very early intrauterine pregnancy
miscarriage
ectopic pregnancy
what are the three main symptoms of an ectopic pregnancies and how many cases present with these symptoms
pain, bleeding, adnexal mass
45%
other three symptoms of ectopic pregnancy (not the three main ones)
amenorrhea
adnexal tenderness
cervical tenderness
ectopic pregnancies usually present around what weeks
5 and 8 weeks
six risk factors of ectopic pregnancies
history of: ectopic pregnancy, gyn surgery, PID
endometriosis
IUCD use
congenital anomalies
assisted reproductive techniques
increased maternal age
PID
pelvic inflammatory disease
four ectopic sites
fallopian tube
cervix
ovary
peritoneal cavity
____ of ectopic cases occur in the isthmus or ampulla of tube
95%
what is the most common location for an ectopic pregnancy
ampulla
2 most dangerous places to have an ectopic pregnancy and why
cervix
interstitial segment of fallopian tubes
high risk of hemorrhage as very vascular areas
2 places free fluid may be seen with ectopic pregnancy
pouch of Douglas
morrison’s pouch
PCDS
pouch of douglas
4 sonographic features of an ectopic pregnancy
adnexal mass
free fluid
absence of IUP/has pseudo sac
live ectopic pregnancy instead of adnexal mass
you can assume the patient was at least ___ weeks pregnant at their first positive pregnancy test
4 weeks
what happens to b hCG levels with ectopic pregancies
same or lower
the b hCG should double every ___ days (up to ___ weeks) with a normal pregancy
2
8
early gestation (less than 5 weeks) b hCG should
increase
spontaneous abortion b hCG should
decrease
PID b hCG should be
negative (not pregnant)
complex ovarian cyst b hCG should be
negative
endometriosis b hCG should be
negative
Ring of Fire
increased blood flow around ectopic gestation but also more often seen around corpus luteum
aborting GS doppler vs ectopic
aborting = avascular
ectopic = well perfused
sliding sac sign
when gentle pressure from the transducer can move the GS = likely abortion in progress
heterotopic pregnancy
intrauterine pregnancy with a twin ectopic pregnancy
chances of a heterotopic pregnancy
1 in 30 000 natural pregnancies
ART
assisted reproductive technology
heterotopic pregnancy incidence in IVF pregnancies
1-3%
if ectopic isnt ruled out, b hCG repeated in ___, scan repeated in ___
2 days
2-7 days
if the intial b hCG level is low (less than ___) and the patient is stable, a further blood test can be taken ___ hours after
1500 iU
48
viable pregnancy = HCG ____ every 48 hours
miscarriage = HCG ____ every 48 hours
if outside these limits =
double
halve
ectopic pregnancy cant be excluded
pseudo sac is seen in ___ percent of ectopic pregnancies
20
interstitial line sign (what/diagnoses)
hyperechoic line (fallopian tube) extending from endo canal up to center of interstitial sac or hemorrhagic mass
helps diagnose interstitial ectopic pregancies
GS must have a minimum of ___ of myometrium surrounding them
5mm
interstitial ectopic pregnancies will be located very ____ in the uterine fundus and have ____ of tissue surrounding the GS
superiorly
less than 5mm
c section scar ectopic occurs where
where c section scar is in uterus, implanted in myometrium not endometrium
methotrexate
cell growth inhibitor
salpingostomy vs salpinectomy
incision in tube to remove ectopic
vs
removal of fallopian tube
if ectopic pregnancy ruptures = blood loss called
hypovolemic shock
laparatomy is what/needed when
incision into abdominal cavity
if ectopic is interstitial, cervical, abdominal, or if patient is severely unstable (going into shock)
what is the most accurate measurement to predict gestational age
CRL
