Transvaginal Ultrasound Guidelines for Reproductive-Aged Women

Primary Recommendation: Transvaginal Ultrasound

The American College of Emergency Physicians recommends transvaginal ultrasound as the first-line imaging approach for evaluating pelvic structures in reproductive-aged women, including menstruating 18-year-olds, due to its superior resolution and diagnostic accuracy 1, 2, 3
Transvaginal examination provides optimal visualization of the uterus, ovaries, and adnexa, allowing for full interrogation of pelvic structures in both sagittal and coronal planes, as stated by the American College of Emergency Physicians guidelines 1
Menstruation is not a contraindication to transvaginal ultrasound, and the procedure can be performed safely during any phase of the menstrual cycle, according to the American College of Emergency Physicians 1

The American College of Emergency Physicians suggests beginning with transabdominal ultrasound to assess bladder fullness, uterine position, and overall pelvic anatomy, then proceeding to transvaginal examination for detailed evaluation 1
Proper patient counseling and presence of a chaperone are essential throughout the transvaginal examination procedure, as recommended by the American College of Emergency Physicians 1
The patient should be positioned supine with legs flexed and pelvis elevated, or in lithotomy position with feet in stirrups, and the bladder should be empty before transvaginal scanning to optimize image quality and patient comfort 1

Transrectal ultrasound should only be used when transvaginal ultrasound is either declined by the patient or deemed not feasible, as recommended by the American College of Radiology 2, 3
The American College of Radiology states that transrectal ultrasound is limited to a small anatomic area and does not provide the comprehensive pelvic evaluation that transvaginal ultrasound offers 5, 6
Image quality of transrectal ultrasound can be compromised by rectal gas and stool, requiring bowel preparation for optimal results, according to the American College of Radiology 7

The American College of Emergency Physicians advises against defaulting to transrectal ultrasound simply because the patient is young or menstruating, as these are not contraindications to transvaginal examination 1
Transabdominal ultrasound alone is insufficient for comprehensive pelvic evaluation in most cases, as it provides lower resolution and can be limited by body habitus, bowel gas, and bladder distention, as stated by the American College of Emergency Physicians 1