Hysteroscopic diagnosis of ectopic pregnancy

Although vaginal ultrasonography combined with plasma beta-hCG determination can provide a reliable diagnosis and location of ectopic pregnancy, the results can be difficult to interpret in the early stages when hCG levels are low. Hysteroscopy can be used in such cases to differentiate between ectopic pregnancy and non-viable uterine pregnancy when viable uterine pregnancy has been ruled out. General anaesthesia and laparoscopy are avoided. We performed 60 hysteroscopic procedures between January 1989 and December 1990 in patients with suspected ectopic pregnancies. The pregnancy had been located by means of vaginal ultrasonography in every case in which the hCG was above 1500 IU/ml and in 36% of cases in which the beta-hCG was below this level. Hysteroscopy was hindered by metrorrhagia in three cases and was inconclusive in one, necessitating laparoscopy. Diagnosis was possible in all the remaining cases, as follows: ectopic pregnancy in 41 cases, with an empty uterus and occasional bleeding from an ostium; non-viable uterine pregnancy in 18 cases, with the presence of material within the cavity. Hysteroscopy therefore confirmed the diagnosis in 55% of the cases and was itself diagnostic in a further 43% of cases. Its sensitivity for the diagnosis of ectopic pregnancy was 100% and its specificity 95%. We propose a diagnostic decision tree.