[Insulin-like-growth-factor-binding-protein 1 (IGFBP-1) and fetal fibronectin in diagnosis of premature rupture of fetal membranes].

The diagnosis of a premature rupture of membranes presents no problem in the vast majority of cases. However, a reliable diagnosis is clinically not possible in about 10%. Most methods available lack the necessary sensitivity and specificity. Since the clinical consequences of a false diagnosis are considerable (overtreatment for false-positive and risk of infection for false-negative results), it is essential to clinically establish new, minimally invasive methods with higher predictive powers. In the present study we compared: the AMNI Check for detection of insulin-like growth-factor binding protein 1 (IGFBP-1); a membrane immunoassay for detection of fetal fibronectin (fFn); pH indicator paper; and, to verify a rupture of membranes in unclear cases, amniocentesis with installation of indigo carmine. The examination was performed in a group of 75 patients, 35 with and 40 without rupture of the membranes. The best results were obtained for the AMNI Check (sensitivity and negative correctness 100%, specificity and positive correctness 83%). With the same sensitivity and negative correctness, the membrane immunoassay for fFn achieved a specificity of 70% and a positive correctness of 74%. The pH indicator paper had the lowest predictive value (sensitivity 94%, negative correctness 93%, specificity 63%, positive correctness 69%). Both the AMNI Check and the test for detection of fetal fibronectin can be recommended for reliable exclusion of premature rupture of membranes. Amniocentesis should however be performed in uncertain cases with a positive test result. Nevertheless, considerable reduction of this invasive method is possible.