UMEM Educational Pearls

Category: Obstetrics & Gynecology

Title: Ultrasound in Pregnancy

Keywords: Ultrasound, ectopic, pregnancy (PubMed Search)

Posted: 2/24/2008 by Michael Bond, MD (Updated: 10/20/2020)
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Ultrasound in Pregnancy

  1.  A full bladder is needed for Transabdominal Ultrasound and an empty bladder for transvaginal ultrasound.
  2. A gestational sac should be visible on transabdominal ultrasound with a quantative HcG of 5000-6000 mIU/ml, and a quant of 1500-2000 mIU/ml on transvaginal.
  3. When taking photos, ensure that you show all of the applicable landmarks.  [i.e.: bladder, and uterus]  If you just zoom in on the pregnancy anybody else (i.e.: your expert witness) reading the scan will not be able to confirm that the pregnancy is in the uterus.
  4. To confirm an IUP, you must see the yolk sac within the gestational sac.  A double decidual sign is an early sign of pregnancy but it is not always seen and should not be relied upon.
  5. If you have a confirmed IUP an additional ectopic pregnancy is extremely unlikely unless the patient was taking medication to stimulate their ovaries (i.e. Infertility treatment).  If on stimulation therapy a very thorough exam needs to be done to look for additional pregnancies.
  6. If Quant >2000 mIU/ml and there is no evidence of an IUP, patient needs to be treated as an ectopic pregnancy.