Various methods for determining urinary choriogonadotropin evaluated for the early diagnosis of ectopic pregnancy

We evaluated the accuracy, sensitivity, specificity, and performance characteristics of seven methods for determining urinary choriogonadotropin in the early diagnosis of ectopic pregnancy in 46 patients with gynecological emergencies. The kits examined included immunoenzymometric assays (Tandem Icon hCG, Model Plus, Diapreg-25, Pregnastick, Nimbus) and reverse hemagglutination inhibition assays (NeoPregnosticon 75 Duoclon, Pregtest). We found immunoenzymometric assays to be the most sensitive procedures (lowest detection limits) for qualitatively detecting hCG secreted by ectopic pregnancy. We concluded that the Tandem Icon best meets our criteria and we advocate its use in the emergency room or ward as the first-line investigation of ectopic pregnancy. In addition, the use of Diapreg-25 has many theoretical advantages as an extremely sensitive index of choriogonadotropin status because of its ability to detect very low concentrations of beta subunit.