Human reproduction
-
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 was the most constant sonographic finding among patients with ectopic pregnancy (n = 89), with a very high sensitivity (0.99) but a low specificity (0.41). The application of different HCG cut-off levels improved specificity to 1.00 for values exceeding 4500 IU/l. ⋯ The additional effect of HCG values on these results was minor. The low HCG cut-off levels advocated in recent studies are questioned by the results of our analysis: whereas the combined use of sonography and HCG measurements is shown to be of great benefit, the limitations are also documented, underlining the need for re-evaluation at intervals of patients with low HCG values. The question of which cut-off level should be used in practice, however, hinges on a difficult choice between a certain specificity and clinical utility.