TRANSVAGINAL SONOGRAPHY AND HUMAN CHORIONIC-GONADOTROPIN MEASUREMENTSIN SUSPECTED ECTOPIC PREGNANCY - A DETAILED ANALYSIS OF A DIAGNOSTIC-APPROACH

In this prospective study among 208 high-risk patients with suspected ectopic pregnancy, the diagnostic value of transvaginal sonography and serum human chorionic gonadotrophin (HCG) measurements were analysed in detail. The absence of an intra-uterine gestational sac obviously w as the most constant sonographic finding among patients with ectopic p regnancy (n = 89), with a very high sensitivity (0.99) but a low speci ficity (0.41). The application of different HCG cut-off levels improve d specificity to 1.00 for values exceeding 4500 IU/l. Clinical utility obviously decreased, as many patients presented with HCG values well below this level. The additional effect of adnexal findings was analys ed. Sonographic identification of an ectopic pregnancy was very specif ic (0.99) but had low sensitivity (0.56) because many ectopics were no t detected. The additional effect of HCG values on these results was m inor. The low HCG cut-off levels advocated in recent studies are quest ioned by the results of our analysis: whereas the combined use of sono graphy and HCG measurements is shown to be of great benefit, the limit ations are also documented, underlining the need for reevaluation at i ntervals of patients with low HCG values. The question of which cut-of f level should be used in practice, however, hinges on a difficult cho ice between a certain specificity and clinical utility.