Sonographic detection of free pelvic peritoneal fluid.

Transvaginal ultrasonography was performed on 113 women prior to laparoscopic sterilization. The amount and character of the peritoneal fluid present in the pelvis was assessed at the end of the operative procedure. Sonographically, free pelvic peritoneal fluid was seen in 42.5% of the patients. Laparoscopically, the average amount of fluid present was 11.2 ml with an average of 16.5 ml present in patients with FPPF and 7.2 ml present in patients without FPPF (P < 0.0001). Sonographic measurement of fluid volume was found to significantly underestimate the amount of fluid present at laparoscopy (P < 0.0001). Endometriosis and pelvic adhesions significantly changed the sonographic findings.