Uterine Sounding: Is There a Difference between Blind and Hysteroscopically Directed Measurements?

To evaluate the accuracy of traditional blind uterine sounding in measuring uterine cavity length (UCL), compared with measurement by hysteroscopic guidance.

A cross-sectional descriptive study (Canadian Task Force classification III).

Academic multispecialty medical center.

Fifty-eight women undergoing elective hysteroscopic procedures.

UCL measurement.

UCL measurements were obtained by the traditional blind sounding technique and by hysteroscopically directed measurement. Hysteroscopic measurements were assumed to represent true uterine cavity length. Differences between the 2 measurements were calculated to analyze error and bias.

Mean UCL for blind sounding and hysteroscopically directed measurements were 80.81 mm and 86.55 mm, respectively. The magnitude of error between measurements was >10 mm in 36.2% of cases, with underestimation of true UCL in 55.17% of cases.

True UCL is underestimated by blind sounding, and the frequency, magnitude, and direction of error may be greater than are clinically acceptable.