SONOGRAPHIC DETECTION OF ECHOGENIC FLUID AND CORRELATION WITH CULDOCENTESIS IN THE EVALUATION OF ECTOPIC PREGNANCY

OBJECTIVE. Because the presence of echogenic fluid on transvaginal son ography has been shown to correlate well with hemoperitoneum in patien ts with possible ectopic pregnancy, the aim of this study was to compa re echogenic fluid on sonography with the results of culdocentesis in predicting hemoperitoneum. MATERIALS AND METHODS. Free fluid on transv aginal sonography and the results of culdocentesis were correlated wit h the presence or absence of hemoperitoneum in 46 patients at surgery. Forty ectopic pregnancies and six nonectopic pregnancies were found, Echogenic fluid was the criterion used to establish hemoperitoneum on sonography. For statistical analysis, negative and nondiagnostic culdo centesis results were combined. The sensitivity, specificity, and posi tive and negative predictive values of each diagnostic technique were compared. RESULTS. In 40 of 46 patients with ectopic pregnancy, the se nsitivity and specificity of echogenic fluid for establishing hemoperi toneum were 100% and 100%, respectively, compared with 66% and 80%. re spectively, for culdocentesis, More important, the negative predictive value of a nondiagnostic culdocentesis was 25% compared with 100% for echogenic fluid in the ectopic subgroup of patients. In two patients with incomplete abortions, sonography failed to detect small amounts o f hemoperitoneum at surgery performed 4 hr and 7 days after sonography . CONCLUSION. Sonography is more sensitive than culdocentesis in the d etection of hemoperitoneum. Culdocentesis is invasive, and nondiagnost ic results cannot be used to exclude hemoperitoneum. Culdocentesis sho uld play no role in the evaluation of ectopic pregnancy except in the unusual circumstance in which high-resolution sonography cannot be rea dily performed.