A RAPID TEST FOR ABRUPTIO PLACENTAE - EVALUATION OF A D-DIMER LATEX AGGLUTINATION SLIDE TEST

OBJECTIVE: Our purpose was to evaluate a rapid latex agglutination slide test for D-dimer, a byproduct of clot lysis, in the prediction of abruptio placentae. STUDY DESIGN: Four groups were studied: (1) 15 patients with normal pregnancies at 40 weeks' gestation, (2) 17 participants with preeclamptic pregnancies, (3) 14 patients with preterm labor, and (4) 15 patients with confirmed abruptio placentae. The latex agglutination slide test was performed with positive and negative reference solutions and plasma dilutions of 1:1, 1:2, 1:4, and 1:8. A test was considered positive if, at 2 minutes, agglutination was present at dilutions of greater-than-or-equal-to 1:2 (greater-than-or-equal-to 1.0 mug/ml fibrin equivalent units). Test results were compared in patient groups with and without abruptio placentae by means of the chi2 test. RESULTS: The likelihood of a positive D-dimer test result was not significantly different among patients in the non-abruptio placentae groups (p = 0.454). Patients in the abruptio placentae group were significantly more likely to have a positive D-dimer slide test result than those in the non-abruptio placentae groups (p = 0.0001). The D-dimer test conferred sensitivity, specificity, positive predictive value, and negative predictive value of 67%, 93%, 91%, and 48%, respectively. In contrast, other laboratory measures of coagulation (e.g., platelet count, prothrombin time, partial thromboplastin time, and fibrinogen levels) yielded no better than a 20% sensitivity for abruptio placentae. CONCLUSIONS: The D-dimer slide test may be a superior rapid method to improve early diagnosis of abruptio placentae.