Journal of Ultrasound in Medicine, Vol 12, Issue 3 145-151, Copyright © 1993 by American Institute of Ultrasound in Medicine
Sonographic diagnosis of ectopic pregnancy with endovaginal probes: what really has changed?
S. A. Russell, R. A. Filly and N. Damato
Department of Radiology, University of California, San Francisco 94143-0628.
To evaluate the impact of endovaginal (EV) sonography in the diagnosis of
ectopic pregnancy, a 2 year retrospective study was performed identifying
123 at-risk patients. Of these 123 women, 19 (15.4%) had a surgically
proved ectopic pregnancy, only three (15.8%) of which were visualized
directly at sonography. A confident diagnosis of an intrauterine pregnancy
(IUP) was made at the initial scan in 74%, which contrasts with 58%
diagnosed at the first transabdominal (TA) scan in an earlier study from
this laboratory, thus confirming an improvement in diagnostic ability with
EV transducers. This study has failed to confirm some findings of other
workers, particularly that adnexal ring-like structures are visualized
frequently in the presence of an ectopic pregnancy. No adnexal rings were
observed in our 19 cases. The combination of an adnexal mass and free
pelvic fluid was found to correlate best with the presence of an ectopic
pregnancy. This study further emphasizes that a significant proportion
(26.3%) of ectopic pregnancies have a normal EV sonogram at presentation.
The group failing to demonstrate an IUP and showing no evidence of an
adnexal mass or pelvic fluid (i.e., a normal pelvic sonogram) carried a 1:3
risk for the presence of an ectopic pregnancy, a result that is very
similar to our data published before the introduction of EV technology. We
conclude that, although it provides a significant improvement and
refinement in the recognition of intrauterine pregnancies, EV scanning does
not permit a confident diagnosis of ectopic pregnancy in many cases.
