We studied for the first time, on a large number of pregnant women (with and without PPROM), the kinetics from the first trimester to delivery of the plasma concentrations (and serum-extracted exosomes) of four major actors of the RAGE system: sRAGE and three of its ligands, HMGB1, AGEs, and S100A8/9. Here, S100A8 is linked to preterm premature rupture of the membranes.