Pelvic ultrasound (transvaginal)

Background

• Also known as endovaginal ultrasound
• Used to evaluate female reproductive organs including uterus, ovaries, fallopian tubes, cervix, and vagina

Indications

• Abnormal uterine bleeding
• Abnormal abdominal or pelvic exam
• Pelvic pain
• Confirm intrauterine pregnancy
• Gestational dating during pregnancy
• Fetal monitoring and surveillance
• Evaluation of placenta
• Evaluate for spontaneous abortion
• Evaluate for ectopic pregnancy
• Uterine fibroids
• IUD placement confirmation
• Ovarian torsion
• Ovarian cysts

Technique

• Probe and transducer
  • Endocavitary probe (high frequency, low penetration)
  • Probe "dot" stays on left side of ultrasound screen
    • Corresponds with anterior structures (if probe marker held at 12:00) and right-sided structures (if probe marker held at 9:00)

• Patient positioning
  • Lithotomy position
  • Gently advance probe into vaginal canal
  • May be more comfortable for patient to insert probe into vagina herself

Findings

• Endometrial stripe: Measured from thickest echogenic area (from one basal endometrial interface to the other, including canal)
  • Pre-menopausal:
    • During menstruation: 2-4mm
    • Early proliferative phase: 5-7mm
    • Late proliferative phase: 11mm
    • Secretory phase: 7-16mm
    • After D&C or SAB: >5mm
      • Consider retained POC if thicker
  • Post-menopausal:
    • With vaginal bleeding: <5mm
    • Without vaginal bleeding: <11mm

Images

Normal

Normal thickened endometrial stripe during secretory phase

Normal thin endometrial stripe during menses

Abnormal

Ectopic pregnancy at the cervix

Free fluid in cul-de-sac, no gestational sac visualized in uterus