The coagulation profile of preterm delivery

Hypercoagulation was suggested to be involved in preterm birth etiology; however, the coagulation state of preterm parturients remains unelucidated. The study aim was to evaluate the haemostatic system of pregnant women with premature uterine contractions (PUC).

The cohort study population consisted of 76 healthy pregnant women admitted with regular PUC. The study group included 38 women who experienced preterm birth; 14 of them had preterm premature rupture of membranes (PPROM). The control group included 38 women who eventually had term delivery. Groups were matched for maternal age, number of births and gestational age at admission. Blood samples were tested for haemostatic parameters and coagulation activation markers.

Significantly shorter PT and aPTT were documented in the study compared to control group (25.7±2 vs. 27.4±2.7seconds, P=0.003, and 9.96±0.5 vs. 10.1±0.4seconds, P=0.05, respectively), although differences in absolute values were small. There was no significant difference between the two groups in levels of: fibrinogen, D-dimer, protein C-global, free protein S antigen, factor VIII activity, Von Willebrand factor, plasminogen activator inhibitor-1, prothrombin fragments F1+2 (PT F1+2), tissue factor and tissue factor pathway inhibitor. Women with PPROM had significantly lower PT F1+2 levels compared to those who had preterm delivery with intact membranes (351±99 vs. 561±242pmol/L, P=0.003).

Shortened PT and aPTT, reflecting increased thrombotic activity in maternal plasma, could serve as a marker of real preterm labor in women with premature uterine contractions. Further prospective studies in a larger cohort are warranted to validate these findings.