Module 6 : First Trimester Abnormal - Extrauterine Pregnancy Flashcards
M mode determines ?
- only definitive way to determine abnormality/viability
Mean Sac Diameter (MSD)
- gestational sac is the first thing we see on us
- used when embryo NOT identified
- ensure you see double decidual sign
- used from 4 - 7 or 8 weeks
- length + width + height / 3
comparing MSD to Embryo
- used for early diagnosis of OLIGOHYDRAMNIOS (less amniotic fluid/not enough amniotic fluid)
- big red flag for abnormal pregnancy
- from 5.5 - 9 weeks if MSD(mm) - CRL(mm) = less than 5mm
+ oligohrydramnios suspected - EFW still calculates MSD on all IVF pregnancies but only use CRL for dating of the pregnancy
first trimester ultrasound tests
- MSD
- CRL
- nuchal lucency
gestational sac sizes on EV
MSD 8mm = yolk sac seen
MSD 16mm = embyo seen
gestational sac sizes on transabdominal
MSD 20mm = yolk sac seen
MSD 25mm = embryo seen
gestational sac average growth
- 1.1mm/day
- up until 8 weeks
Crown Rump Length (CRL)
- used between 6 - 13 weeks
- MOST ACCURATE MEASUREMENT TO PREDICT GESTATIONAL AGE +/- 3 DAYS
- measure from tip of head to end of rump
- do not include yolk sac
- in a neutral position
ectopic pregnancy - definition
- pregnancy that occurs outside the uterine cavity
ectopic - Classical Clinical Triad
- pain
- bleeding
- adnexal mass
- 45% demonstrate these symptoms
other ectopic symptoms
- Amenorrhea
- adnexal tenderness
- cervical tenderness
timing of ectopic pregnancy
- usually present themselves between 5 - 8 weeks
+ to small to cause any pain before this time
+ also when they start to rupture because of lack of blood supply
factors increasing risk of ectopic
- tubal surgery
- pregnancy with an intrauterine contraceptive device
- pelvic inflammatory disease PID or STD
- previous ectopic
- endometriosis (endometrium travels to fallopians)
- previous appendicitis
- Khrons disease
common ectopic sites
- Fallopian tube (95%)
- cervix
- interstitial segment of tube
- ovary
- peritoneal cavity
highest risk ectopic locations
- cervix and cornua (interstitial) areas are the most dangerous
- high risk of hemorrhage because there are very vascular areas with little or no thickened endometrium for the embyo to burrow into
- also no coagulation takes place to bleeding out may occur
sonographic features of ectopic
- adnexal mass
- free fluid
+ in pouch of Douglas even up to kidneys in Morrisons pouch - absence of and IUG (intrauterine gestational sac) or presents with pseudo sac
- may see a viable ectopic pregnancy instead of adnexal mass
viable ectopic pregnancy
- gestational sac with an embryo with a heart beat seen outside the uterus
- this is 100% accurate diagnosis of an ectopic
- may also indicate the at pregnancy has not yet ruptured
Menstrual history
- DONT trust info given by patient in case of ectopic
- knowing when first pregnancy test was positive is helpful
+ can assume patient was atlas 4 weeks pregnancy at this time - good question to ask every OB patient
b hCG
- common to have lower than normal level of beta hCG or still be in normal range
- b hCG should double every 2 days in a normal pregnancy but should not with an ectopic pregnancy
DDx (differential diagnosis) using blood work
- early gestation \+ 5 weeks \+ b hCG should increase - Spontaneous abortion \+ b hCG should decrease - PID \+ pelvic inflammatory disease \+ b hCG negative - not pregnant
heterotopic pregnancy
- intrauterine pregnancy with a twin ectopic pregnancy
- 1/7000 incidence
- incidence has increase with ART (assisted reproductive technology/IVF)
+ 1/100
negative ultrasound results
- does not rule out ectopic
- may be to small to recognize with sonography
- MUST FOLLOW UP
+ EV if not done already
+ repeat bhCG in 2 days
+ repeat scan in 1 week
interstitial line sign
- echogenic line extending from the endometrial canal up to the centre of the interstitial sac or hemorrhagic mass
- used to help diagnose interstitial ectopic pregnancy
how much myometrium must be surrounding gestational sac
- MUST HAVE MINIMUM OF 5mm OF MYOMETRIUM SURROUNDING IT
- if not interstitial ectopic
cervical ectopic
- very low in uterus
- if moves with pressure from EV then its a spontaneous abortion if doesnt move then ectopic pregnancy
treatment for ectopic - surgery
- resection of diseased tube
- ow patient has an increased risk of repeat of ectopic
treatment for ectopic - medically
- with methotrexate
+ cell growth inhibitor
+ used in cancer patients to arrest growth of cancer - injected IV, IM or directly into ectopic site
- or taken orally
treatment of acute ectopic - laparoscopy
- surgical removal with laparoscope
- when medical treatment has failed
- hemodynamically unstable
+ internal bleeding
treatment of acute ectopic - laparotomy
- may be required if ectopic is
\+ abdominal
\+ cornual
\+ interstitial
\+ cervical
\+ patient is severely hemodynamically unstable or in shockconservative management
- some early ectopics can resolve on their own
+ decreasing hCG
+ absent gestational sac - medical treatment
+ methotrexate = single or multiple doses - monitoring hCG
