AMNIOTIC-FLUID PLASMINOGEN ACTIVATORS AND INHIBITORS AND TAT-COMPLEX LEVELS DURING 2ND TRIMESTER PREGNANCY AND LABOR

The levels of haemostatic variables in amniotic fluids of normal 2nd t rimester of pregnancy and during labour were determined. t-PA antigen and PAI-1 levels were significantly increased during labour in compari son to 2nd trimester. t-PA/inhibitor complexes and single-chain urokin ase plasminogen activator (scu-PA) were present with free t-PA seen on ly during labour but not during 2nd trimester pregnancy, PAI-1 activit y was not detectable during 2nd trimester but a mean value of 23.2 +/- 14 AU/ml was observed during the labour, PAI-2 antigen levels remaine d elevated whilst fibrinogen, Factor X and plasminogen were not detect able in the amniotic fluids studied, Functional ATIII was not detected during labour but low activity (mean 21.3 +/- 8.9%) was seen in 21 of the 25 amniotic, fluid samples collected in 2nd trimester of pregnanc y, ATIII antigen levels of mean 0.015 +/- 0.005 g/L and 0.012 +/- 0.00 3 g/L were found during the 2nd trimester and labour respectively, Sig nificant increase in t-PA activity in maternal plasma as compared to a mniotic fluid was observed during labour although no significant diffe rences in u-PA, PAI-2 and PAI-1 activity levels were observed, The inc reased fibrinolytic activity in the plasma during labour and an overwh elming inhibitory capacity of the amniotic fluid prepare the subject f or the haemostatic challenge of delivery.