Journal of Ultrasound in Medicine, Vol 8, Issue 1 15-19, Copyright © 1989 by American Institute of Ultrasound in Medicine
Prediction of cesarean section scars with ultrasound imaging during pregnancy
N. M. Lonky, N. Worthen and M. G. Ross
Department of Obstetrics and Gynecology, Harbor UCLA Medical Center, California.
We sought to determine whether a sonographic examination could identify
uterine scars in patients with a history of previous cesarean section and
further distinguish patients having previous low transverse from vertical
uterine incisions. Forty-six antenatal obstetrical patients with a history
of prior cesarean section(s) and 30 control patients without prior uterine
surgery underwent sonogram examinations to identify the scar. The
researcher who later reviewed the sonogram was blinded as to the presence
or type of uterine scar. Of the 47 scars examined, uterine scars were
visualized in 13 (27.7%). All scars seen were low transverse; no vertical
scars were identified by sonography (p less than .05). No scars were
visualized with sonography in the control group and cesarean section scars
were seen more easily prior to the third trimester. No information
concerning the scar condition (dehiscence) could be obtained with
sonography. We conclude it is of benefit to perform sonogram exams in
patients with prior cesarean sections of unknown incision to better counsel
them as to their risk to rupture. Although vertical cesarean section scars
could not be visualized, those patients who had low transverse scars
identified could be included in a low-risk vaginal birth population.
