The Mark-7 intrauterine sound - an accurate determinant of uterine axial length.
The axial uterine length of 60 nulliparous patients has been measured using a standard Galabin sound and a new flexible disposable sound (Mark-7). In 47 patients the values obtained with the plastic sound were between 0.25 cm to 0.5 cm greater than the values obtained with the metal sound. The flexible plastic sound values are probably larger because this sound is able to follow uterine axial curvature. The element of parallax error which is inherent in using metal sounds is avoided by use of a sliding half-collar at the distal end of the instrument, which can be moved against the cervix allowing fixed measurement. This instrument should be a useful adjunct to intrauterine device research and usage where the relationship of uterine length to device performance is being considered.
D005260:Female; D006801:Humans; D007435:Intrauterine Devices, Copper; D013016:Sound; D014599:Uterus / Q000033:anatomy & histology*