Pitfalls in the transvaginal sonographic diagnosis of ectopic pregnancy.

Transvaginal sonograms (TVS) of 40 adequately documented ectopic pregnancies were reviewed retrospectively. Difficulties that interfered with the accurate demonstration of the adnexal mass of the ectopic pregnancy were identified in 21 of these studies (52.5%). In three cases (7.5%) the ectopic pregnancy was visualized in an erroneous location. In 11 cases (27.5%), the ectopic pregnancy was overshadowed by coexisting pathologic findings, misinterpreted as a bowel segment or poorly demarcated from the adjoining ovary. In seven cases (17.5%), the adnexal mass of an ectopic gestation was completely over-looked on initial TVS. TVS in the women suspected of having an ectopic pregnancy must be performed meticulously and with due consideration to the pitfalls described.