RESUMO
The Authors studied the behaviour of anticomplement and heparin-like activities in human term placentas in relation to intrauterine fetal growth retardation. These two biological activities might be involved in regulatory mechanisms of great importance for the fetal growth. The anticomplement activity was significantly lower in IUGR placentas than in controls, while no change was found in heparin-like activity. The decrease of anticomplement activity might be associated to immunological mechanisms, possibly related to a placental microcirculation damage, with consequent fetal growth retardation. For what concerns HCS and E3 plasma levels during pregnancy, a significant reduction of HCS in IUGR subjects was observed, confirming a decreased functional activity of placenta. The E3 levels, on the contrary, were slightly, but not significantly lower in IUGR patients.