VENTRICULAR EJECTION FORCE IN GROWTH-RETARDED FETUSES

The objective of this study, was to determine whether in growth-retard ed fetuses secondary to uteroplacental insufficiency the cardiac ventr icles exert a force different from that of appropriately grown fetuses . Doppler echo-cardiographic studies were performed in 156 appropriate ly grown fetuses (gestational age 18-38 weeks) and in 72 growth-retard ed fetuses (gestational age 24-36 weeks) free from structural and chro mosomal abnormalities and characterized by Doppler changes in the umbi lical artery and middle cerebral artery suggesting uteroplacental insu fficiency as the most likely etiology of the growth defect. Right and left ventricular ejection force values were calculated from velocity w aveforms recorded at the level of aortic and pulmonary valves, accordi ng to Newton's second law of motion. In appropriately grown fetuses, l eft and right ventricular ejection force values significantly increase d with advancing gestation and the two ventricles exerted similar for ce. In growth-retarded fetuses, the ventricular ejection force was sig nificantly and symmetrically decreased in both ventricles. Among growt h-retarded fetuses, a poorer perinatal outcome was observed in those f etuses in which the ejection force of both ventricles was below the 5t h centile of the normal limits for gestation. In 12 growth-retarded fe tuses followed longitudinally during the last week preceding intrauter ine death or Cesarean section due to antepartum heart-rate late decele rations, a significant decrease of ejection force was found in both ve ntricles. Finally, a significant relationship was found between the se verity of acidosis and light and left ventricular ejection force value s in 22 fetuses in which Doppler recordings were performed immediately before cordocentesis. In conclusion, in growth-retarded fetuses the f orce exerted by the ventricles was symmetrically reduced and the degre e of impairment seemed to be related to the severity of fetal compromi se.