INCREASED BLOOD-FLOW RESISTANCE IN PLACENTAL CIRCULATION AND LEVELS OF PLASMINOGEN-ACTIVATOR INHIBITORS TYPE-1 AND TYPE-2 IN SEVERE PREECLAMPSIA

To study whether increased resistance in the placental circulation cha nges the plasma levels of plasminogen activators types 1 and 2 (PAI-1 and PAI-2) in severe preeclampsia, the levels of PAI-1 activity and PA I-2 antigen were determined in 33 severely preeclamptic and 22 normal pregnant women during gestational weeks 24-35. In the preeclampsia gro up, the Pulsatility Index (PI) of the umbilical artery was investigate d with Doppler ultrasound. The levels of PAI-1 activity were higher (P < 0.01) whereas those of PAI-2 antigen were lower (P < 0.01) in the p reeclampsia group than in the normal pregnancy group. The patients wit h abnormally high PI (high PI group) had increased PAI-1 levels (P < 0 .05) and unchanged PAI-2 levels (P > 0.05), compared with those with n ormal PI (normal PI group). The levels of PAI-1 were positively correl ated to the PI values during pregnancy weeks 34-35 only in the high PI group (r = 0.88, P < 0.05). In conclusion, high resistance in the pla cental circulation elevates plasma PAI-1 activity levels but does not influence PAI-2 antigen levels.