Circulating procoagulant microparticles in women with unexplained pregnancy loss: a new insight

One of the frequently proposed mechanisms for pregnancy losses refers to ut eroplacental thrombosis. However the contribution of classical thrombotic r isk factors remains questionable and, if real, does not account for a large number of pregnancy losses. The aim of this study was to investigate the p resence of circulating procoagulant microparticles, a new marker of cell ac tivation already associated with various prothrombolic clinical settings. M icroparticles were assessed by an original prothrombinase assay on platelet depleted plasma obtained from 74 women with a history of pregnancy loss wi thout apparent cause and 50 controls. Patients were studied at least 2 mont hs after the last obstetrical event and were classified into 2 groups: 49 w omen with at least 3 consecutive spontaneous abortions at or before the 10t h postmenstrual week and 25 with at least one fetal death beyond the 10th p ostmenstrual week. Among the 74 patients, 41 had increased levels of circul ating microparticles, 29 belonging to the group of early pregnancy loss (59 %) and 12 to the group of late pregnancy loss (48%). The high prevalence of increased levels of procoagulant microparticles in both groups makes this new marker very promising for the understanding, follow up and therapeutica l handling of pregnancy loss.