Comparison of abdominal and vaginal sonography in suspected ectopic pregnancy.

We compared the accuracy of vaginal sonography in 100 women suspected of having an ectopic pregnancy, in whom a living fetus was not seen by abdominal sonography. Vaginal sonography provided more useful diagnostic information in 44% of the cases, 31% of the ectopics and 52% of the intrauterine pregnancies. Among the 39 ectopic gestations, vaginal scanning was more accurate than abdominal scanning in detecting the ectopic pregnancy (90 versus 80%) and cul-de-sac fluid (77 versus 46%), in identifying an ectopic gestational sac (69 versus 44%), and in diagnosing a tubal pregnancy as unruptured (76 versus 50%). Only one false-positive diagnosis was made by each method of scanning. Among the 61 intrauterine pregnancies, vaginal scanning allowed a more accurate detection of the content of the sac (fetus/yolk sac) in 49% of the cases. In two women, normal intrauterine sacs of 2 and 2.5 mm were detected only by vaginal scanning, at hCG levels of 740 and 840 IU/L (First International Reference Preparation), respectively. Vaginal scanning appears important for early diagnosis of intrauterine pregnancy and more accurate diagnosis of ectopic pregnancy.