Decreased prostacyclin production by placental cells in culture from pregnancies complicated by fetal growth retardation.

Production of prostacyclin (PGI2) in vitro by human placental cells from pregnancies complicated by fetal growth retardation was significantly reduced compared with that in placental cells from normal pregnancies of either matched gestation or at term. This appeared to be due to a reduction of synthesis of PGI2 rather than to any alteration in the rate of its enzymic metabolism. Addition of oestradiol and progesterone increased PGI2 production by cells from pregnancies with fetal growth retardation in a similar manner to that by cells from first trimester pregnancies, implying that the placental cells are not irreversibly damaged by ischaemia. The decreased PGI2 production by cells of trophoblastic origin may be an aetiological factor in the thrombotic occlusion of the uteroplacental circulation which impairs fetal growth.