Comparison of two rapid strip tests based on IGFBP-1 and PAMG-1 for the detection of amniotic fluid

Our objective was to compare two rapid strip tests for the detection of amniotic fluid, based on the detection of insulin-like growth factor-binding protein-1 (IGFBP-1) and of placental alpha-microglobulin-1 (PAMG-1). Samples of amniotic fluid were taken in 20 pregnant women between 31 3/7 and 41 2/7 gestational weeks at elective cesarean section before delivery of the newborn. These samples were diluted with 0.9% saline solution in a dilution series down to concentrations of 1:320. Immunoassay strip tests were then compared in their ability to detect remaining concentrations of amniotic fluid. In 5 cases, both test methods showed the same results. In all remaining 15 cases, the test based on PAMG-1 proved to be superior by detecting amniotic fluid at least at one descending concentration below the test based on IGFBP-1. Thus, the rapid strip test based on PAMG-1 seems to be a more sensitive bedside test compared with the test based on IGFBP-1 for the detection of amniotic fluid.