SPHP Radiology Protocols

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First Tri OB

First Trimester OB US (last edited 11/7/2019)
(last reviewed 11/7/2019)

  1. Sag midline uterus. Measure length and AP dimension.
  2. Trans uterus (largest view). Measure width.
  3. Sag uterus, right
  4. Sag rt ovary, with and without measurement – length and AP dimension
  5. Trans rt ovary, with and without measurement – width dimension
  6. Sag uterus, left
  7. Sag lt ovary, with and without measurement – length and AP dimension
  8. Trans lt ovary, with and without measurement – width dimension
  9. Trans vagina
  10. Trans cervix
  11. Trans body
  12. Trans fundus
  13. Trans superior to uterus
  14. Sagital fundus, include the gestational sac
  15. Transverse fundus, include the gestational sac

NO COLOR DOPPLER/ DOPPLER ON A VIABLE IUP

  1. Measure crown rump length (x2)
  2. Measure gestational sac if CRL is out of range
  3. Show yolk sac, fetal pole, amnion
  4. Do M-mode for heart rate

Uterus:

Sagittal uterus, transverse of fundus, cervix and vagina.

Ovaries:

Sagittal and/or transverse view of both ovaries. Measure ovaries.

Gestational sac:

Show gestational sac and its location in the uterus. Show yolk sac, fetal pole and amnion. Measure crown-rump-length (CRL) or measure gestation sac in three dimensions if CRL is out of range. Do M-mode for heart rate.

FIRST TRIMESTER:

If the patient declines, or if the referring healthcare provider indicates that he/she does not want transvaginal US performed, do not perform transvaginal US. 

Unless patient declines/refuses, transvaginal US scanning should be part of routine first trimester OB US prior to 10 weeks.   Additionally, if the referring healthcare provider indicates NOT to perform transvaginal US, it should not be performed.   Transvaginal scanning yields more accurate measurements (MSD, CRL) and is more sensitive in detecting embryonic cardiac motion and failed first trimester gestation. 

Guidelines for failed first trimester gestations (based on transvaginal scanning):
  • MSD >25mm without fetal pole
  • CRL >/=7mm without cardiac activity
  • cessation of previously demonstrated cardiac activity
  • lack of live embryo 11 days after demonstration of GS WITH yolk sac
  • lack of live embryo 14 days after demonstration of gestational sac WITHOUT yolk sac

*(ok to use color Doppler on non-viable embryo/to show no cardiac activity; do not use Doppler on live fetal pole)

*please use CRL (not MSD) in calculation of gestational age when there is a fetal pole

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