A false positive immunologic pregnancy test with tubo-ovarian abscess.

Abstract

6 patients had tubo-ovarian abscesses and coexisting false positive pregnancy tests with a latex agglutination technic (Gravindex) but not with a hemagglutination-inhibition technic (UCG). In 5 of the cases hysterectomies and bilateral salpingo-oophorectomies were performed. Pathological examination of removed tissues confirmed the absence of pregnancy in all 5 cases. Clinical and laboratory followup confirmed that the other patient was not pregnant. The Gravindex test was negative 2 months after antibiotic therapy. Confusion with ectopic pregnancy may result if only 1 immunologic pregnancy test is available. Urine specimens containing more than 25 mg of protein per 100 ml give a high incidence of false-positive Gravindex tests but not with the UCG test. These patients all had less than 25 mg protein per 100 ml urine. Although several types of tumors and other clinical conditions have been reported as giving false-positive pregnancy tests tubo-ovarian abscess had not been so reported previously. Nonspecific interference rather than a cross-reacting substance in the urine is believed responsible.