Up to 40 percent of women of reproductive age in the United States develop uterine leiomyomas. This condition is reported to be the principal indication for approximately one third of all hysterectomies. The size of the uterus is the major determinant of symptoms, probability of surgery and choice of surgical procedure. The traditional assessment of uterine size relies on bimanual examination. Ultrasound examination is commonly used to confirm bimanual assessments, but it is not clear if ultrasound studies add to clinical information. Cantuaria and colleagues compared bimanual and ultrasonographic assessment of uterine size in patients with leiomyomas to clarify the role of ultrasonography.

A total of 111 women who underwent ultrasound examination before hysterectomy for uterine leiomyomas were retrospectively studied. Before the ultrasound examination, uterine size was estimated by bimanual examination performed by a senior resident and confirmed by an attending physician. The results of the bimanual examination were reported in terms of equivalent gestational size. Uterine dimensions on ultrasound were converted to equivalent gestational size using an established formula. Each uterus was weighed and measured after surgery.

On bimanual examination, uterine size estimations ranged from six to 25 weeks. In four patients, bimanual estimations were not possible because of obesity. The correlation between bimanual and ultrasound estimations was highly significant. Body mass index did not influence this correlation. Both bimanual and ultrasound estimates correlated with the actual size of pathologic specimens.

The authors conclude that routine ultrasound examination is not indicated when bimanual assessment of uterine leiomyomas is performed by an experienced examiner. Ultrasonography may provide useful information when bimanual examination and assessment are difficult, as in the case of extremely obese patients.