Journal of Ultrasound in Medicine, Vol 9, Issue 12 717-723, Copyright © 1990 by American Institute of Ultrasound in Medicine
Translabial ultrasound of the third-trimester uterine cervix. Correlation with digital examination
B. S. Mahony, D. A. Nyberg, D. A. Luthy, J. H. Hirsch, D. E. Hickok and C. N. Petty
Department of Ultrasound, Swedish Hospital Medical Center, Seattle, Washington.
This prospective blinded study compared translabial ultrasound (TLU) and
digital palpation of the cervix among women whose cervix could not be
visualized adequately or at all with transabdominal ultrasound during the
third trimester of pregnancy. The cervical canal and internal cervical os
were adequately visualized during 109 of 113 TLUs (96%). The TLU was well
tolerated by the patients; only two patients refused the TLU pending
discussion of the technique with their obstetrician. Among 43 examinations
of patients without clinical cervical effacement, TLU showed a cervical
length of 2.5 to 4.2 cm (mean, 2.9 cm). An excellent correlation (R = 0.90)
was noted between cervical length on TLU and percentage of cervical
effacement on digital examination. The correlation between amount of
cervical dilatation on TLU and on digital examination was not high (R =
0.58). We conclude that the measurements of cervical length on TLU
correlate well with the amount of cervical effacement on digital
examination and that TLU provides a rapid and well-tolerated alternative
technique to visualize the third-trimester uterine cervix.
