Reduced biological half-life of plasma prostacyclin in pre-eclampsia.

The biological half-life of prostacyclin was short (5.02 +/- 2.10 min) in 5 out of 7 patients with pre-eclampsia; in the remaining two patients the half-life was normal at 9.78 and 10.27 min, respectively. Four weeks after delivery, the half-life was 5.83 min in one patient but had returned to normal 10.16 +/- 1.77 min) in the other four. In normal pregnancy and healthy non-pregnant females the values were within the normal range. The shortened half-life of PGI2 may account for a decreased local availability of biologically active PGI2 with the consequent decrease in placental perfusion, growth retardation and thrombosis which are often seen in pre-eclampsia.