Mod 6 Flashcards
Mean sac diameter
MSD
Used when embryo is not identified
Used from 4-8 weeks
What do you measure in MSD
Length+width+height \ 3
What do you have to ensure you see when see the MSD
Double decidual reaction
Why is the MSD compared to the embryo
Useful in early diagnosis of oligohydraminos
What does oligohydraminos mean
Low fluid
What is the formula for calculating oligohydraminos
MSD(mm)-CRL(mm)
When is the oligohydraminos calculated and what does the calculation have to be less than for oligohyraminos to be suspected
5.5-9 weeks
<5mm
What is calculated/assessed in the 1st trimester scan
MSD
CRL
Nuchal lucency
How much does the gestational sac grow each day
1.1 mm / day
An EV scan should have what kind of MSD
8mm if yolk is seen
16mm if embyro is see
A transabdominal scan should have what MSD
8mm-yolk seen
16mm- embryo seen
When is a CRL used
Between 6 and 13 weeks
What is the most accurate measurement to predict gestational age +/- 3 days
CRL
Where do you measure on a CRL
Tip of the head to the end of the rump
What do you not include on a CRL
Yolk sac
What position should the fetus be in for a CRL and what position is the probe in
Neutral position
Probe is midline sag
What are the US findings with an ectopic
No IUP PUL (pregnancy of unknown location) Free fluid in posterior cul de sac Lt adnexal mass Fetal pole identified in mass with FH seen
What does the free fluid in the posterior cul de sac indicate
Pregnancy has ruptured
What is the definition
A pregnancy that occurs outside the uterine cavity
What is the classical clinical triad
- Pain
- Bleeding
- Adnexal mass
What percentage of people present with these symptoms
45
What are other presenting symptoms of ectopic pregnancy
Amenorrhea
Adnexal tenderness
Cervical tenderness
When does ectopic pregnancies usually present
Between 5-8 weeks
what are the risk factors that can result in ectopic pregnancies
tubal surgery pregnancy with an IUCD PID previous ectopic endometriosis chrons disease previous appendicitis
what is the risk of an ectopic presenting in the other tube after it presented in one
50%
what does PID stand for
pelvic inflammatory disease
where are the sites of ectopics
fallopian tubes cervix interstitial segment of the tube ovary peritoneal cavity
what percentage of ectopics occur in the ampulla
95%
what are the most dangerous areas to have an ectopic
cervix
cornua areas
what is another term for the cornua area
interstitial
why is having an ectopic in the cornua area the most dangerous
it is one of the only areas in the body that wont coagulate
why are the cornua area and cervix the most dangerous
high risk of hemorrage because they are highly vascular areas with little or no thickened endometrium for the embryo to burrow into
what are the sonographic features of an ectopic
adnexal mass
free fluid
absence of an IUG or presents with a pseudo sac
may see a viable ectopic pregnancy instead of adnexal mass
what is a viable ectopic
gestational sac seen with an embryo with a heart beat seen outside of the uterus
100% accurate for the diagnosis of an ectopic
may also indicate that the pregnancy has not yet ruptured
should the menstrual history of that is given by the patient be trusted
not in this case, however knowing when the first pregnancy test was postitive is helpful
what is common of the ß hCG levels
lower than normal but can still be in the same range
what should happen to the ß hCG levels in a normal pregnancy but not with a ectopic pregnancy
levels should double every 2 days
in early gestation, 5 weeks, what should happen to the levels of ß hCG in the blood work
should increase
what would happen to ·ß hCG levels in the blood in the case of a spontaeous abortion
should decrease
in the case of PID what should the ß hCG levels in the blood be
negative, not pregnant
what is a heterotopic pregnancy
an interuterine pregnancy with a twin ectopic pregnancy
what is the rarity of a heterotopic pregnancy
1/7000 incidences
what did the ratio of heterotopic pregnacies use to be
1/40000
why have the incidences of heterotopic pregnanices increased
due to ART
what does ART mean
assisted reproductive technology
what does a negative ultrasound result mean for ectopic and why
does not rule out ectopic as it may be too small recognize with sonography
what must be done in a follow up to rule out ectopic
ev
ß hCG levels repeated every 2 days
scan repeated in one week
what is the interstitial line sign
echogenic line extending from the endometrial canal up to the center of the interstitial sac or hemorrhagic mass
what is the interstitial line sign help diagnosis
interstitial ectopic pregnancies
gestational sacs must have a minimum of how many mm of what surrounding it
5mm of myometrium
