Early Pregnancy
Indications
Depends on Specialty**
Confirm IUP
Confirm Viability
Evaluate for free fluid in pelvis
Evaluate for torsion
Evaluate for structural abnormalities of uterus and ovaries
Evaluate for ectopic
Acquisition
Coronal and Sagittal Views of the Uterus
Ovaries in 2 Planes
Set up
Probe choice:
Transabdominal view: curvilinear
Transvaginal view: endocavitary
Patient position:
Supine
Ask the patient to tuck a towel into their pants to avoid getting gel on their clothes!
For transvaginal US, patient is positioned either frog leg or supine lithotomy
Settings: OB settings!
Views:
Transabdominal long axis
Transabdominal short axis
Transvaginal long axis
Transvaginal short axis
Having trouble?
For a transabdominal view, a full bladder will improve your view because it pushes bowel gas out of the way and allows for better penetration of sonographic waves.
For a transvaginal view, an empty bladder is best
Transabdominal long axis
Place the probe just above the pubic bone with the indicator pointed to the patient’s head
Identify your landmarks
Bladder: anechoic in the near field
Uterus: hypoechoic with a hyperechoic endometrial stripe toward the leading edge
Anteverted uterus: the fundus is pointed anteriorly
Retroverted uterus: the fundus is pointed posteriorly
Fan side to side to completely visualize the uterus
Identify spaces that free fluid collects
Vesicouterine Pouch: between bladder and uterus
Rectouterine Pouch (Pouch of Douglas): between rectum and uterus
Lowest point in peritoneal cavity when patient lying supine. Fluid collects here before vesicouterine pouch!
Transabdominal SHORT axis
Place the probe just above the pubic bone with the indicator pointed to the patient’s right
Identify your landmarks
Bladder: anechoic in the near field
Uterus: hypoechoic with the endometrial stripe appearing as hyperechoic dot in center
Slide your probe to the left and right on the patient to scan for the ovaries
Ovaries: left and right ovaries appear as hypoechoic structures on either side of the uterus
You may not be able to visualize the ovaries unless some pathology is present!
Fan through to completely visualize the uterus
TransVAGINAl long axis
Insert the probe into the patients vagina with the indicator pointed towards the ceiling, handle pointing down
Rock the probe gently downwards to visualize the uterus
Fan the probe left and right to completely visualize the uterus
Also attempt to identify the ovaries
TransVAGINAl SHORT axis
After obtaining your long axis view, rotate the probe 90 degrees so that the indicator is now pointed toward the patient’s right
Gently fan the probe anterior and posterior to visualize the uterus completely
Gently rock the probe left and right to visualize ovarian pathology
Approach to identifying an intrauterine pregnancy
Determine location: intrauterine or not
You are not always able to visualize an ectopic pregnancy.
Gestational sac: anechoic cyst with hyperechoic circle
First sign of pregnancy
Does NOT confirm intrauterine pregnancy
Yolk sac: anechoic cyst attached to gestational sac
Evidence of intrauterine pregnancy
Appears around 5-6 weeks
Fetal pole: hyperechoic bean attached to yolk sac
Evidence of intrauterine pregnancy
Appears around 6-7 weeks
At this time, a fetal heart beat is also visualized
No intrauterine pregnancy at 5-6 weeks gestation with bhCG > 3500? Suspect ectopic!
Red: yolk sac, yellow: fetal pole
pathology and variations
This is often a normal finding as part of the menstrual cycle and can be seen in early pregnancy
Non Ruptured Ectopic
25 y female 6 weeks post partum with increased pain, fever and vaginal bleeding after lochia had stopped
Ultrasound G.E.L. Podcast
Want to learn more? Take a listen to a review of the literature!
