Free echogenic pelvic fluid: correlation with hemoperitoneum.

Echogenic fluid is an important extrauterine finding of ectopic pregnancy. The purpose of this study was to determine how accurately echogenic fluid correlates with hemoperitoneum at surgery. Transvaginal sonography was performed in 831 consecutive patients referred to rule out ectopic pregnancy over a 36 month period. Scans were retrospectively evaluated for the presence or absence and echogenicity of free pelvic fluid. Subsequently, 185 patients had a laparotomy or laparoscopy and had documentation of the presence or absence of hemoperitoneum. On transvaginal sonography 125 patients had echogenic fluid, 30 patients had anechoic fluid, and 30 patients had no fluid. Of the 125 patients with echogenic fluid, 122 (98%) patients had hemoperitoneum; none of the patients with anechoic fluid or no detected fluid had hemoperitoneum (0%). Echogenic fluid had a sensitivity of 100%, specificity of 95%, positive predictive value of 98%, and an accuracy of 98% for detecting hemoperitoneum. This study demonstrates that echogenic fluid detected by transvaginal ultrasonography accurately correlates with hemoperitoneum detected at surgery in patients with suspected ectopic pregnancy.