Circulating microparticles in umbilical cord blood in normal pregnancy and pregnancy with preeclampsia

Placenta microthrombi being one of the prevalent recurrent histological findings in women with preeclampsia (PE), it is reasonable to think that the study of coagulation alterations in cord blood could be more informative than that observed in maternal blood. The aim of the present study was to measure different subtypes of microparticles (MP) plasma levels in the maternal peripheral blood at labour and in the venous cord blood of pregnant women with PE compared to those in a group of women without PE.

Thirty-two pregnant women in labour, 16 with and 16 without PE, were enrolled. Blood samples were collected immediately after delivery from cord blood and from maternal peripheral blood. Total, cellular-derived and tissue factor- bearing MP were analyzed using flow-cytometry. Procoagulant activity of MP was assessed using the STA® Procoag PPL assay.

Total MP, platelet activated-derived (P-Selectin+), leukocyte-derived and TF+MP were higher in pregnancies complicated by PE as compared with normotensive women (p<0.05). Platelet-derived MP (CD61+) levels were lower in PE than in healthy women and no difference was found in endothelial-derived MP levels between the two groups. The PPL clotting time was significantly shorter in PE compared with controls. When only venous cord blood was analysed, all MP detected were significantly higher in PE than in healthy normotensive women (p<0.05).

MP are very likely involved in the hypercoagulable and pro-inflammatory intravascular reactions during PE. Prospective studies in a larger population are needed to define the clinical meaning of MP measurement in the PE setting.