Ultrasound Measurements of the Uterus

Technique for Ultrasound Examination

The American College of Emergency Physicians recommends that the uterus should be examined systematically in at least two orthogonal planes (short and long axis), tracing from the fundus to the cervix, with specific measurements that vary according to parity and clinical context 1, 2, 3, 4, 5, 6
The patient should be positioned in a supine position with the transducer placed on the lower abdomen just above the pubic symphysis for the transabdominal approach 1, 5
The bladder should be distended with the bladder dome just above the uterine fundus, as the bladder serves as an acoustic window 1, 5, 7
Images should be obtained in sagittal and transverse planes, aligning the transducer with the long axis of the uterus (frequently angled to the right or left of the midline) 1, 5
The transvaginal approach is preferred when acceptable to the patient 8

Not examining in two complete planes can lead to missed important findings outside the center or endometrial canal, such as interstitial pregnancy or fibroids 1, 2, 3, 4, 6
Not tracing completely from fundus to cervix is necessary to confirm that the uterus is being scanned and not a large ectopic pregnancy gestational reaction 1, 2, 3, 4, 6
Inadequate bladder distension limits visualization in the transabdominal approach 1, 7

The Endocrinology and Metabolism society recommends documenting the date of last menstruation 8
The frequency of the transducer used should be documented 8
The approach/route of evaluation (transabdominal vs transvaginal) should be documented 8
The three dimensions and volume of each ovary should be documented 8
The endometrial thickness and appearance should be documented (endometrial evaluation of 3 layers may be useful for screening of endometrial pathology) 8
Other ovarian and uterine pathology, as well as ovarian cysts, corpus luteum, and dominant follicles ≥10 mm should be documented 8
A volume of ≥10 ml in any ovary is considered increased (using endovaginal transducers with frequency including 8MHz) 8