Ejection fraction (EF%) by planimetric on the left ventricle is a measurement to monitoring the fetal cardiac function. Hsiech and col study founded no differences between ejection fraction of the left ventricle through gestation; however Menon and col. reported after twenty gestation weeks a light decrease in the ejection fraction of the left ventricle. Our objective in this study is to correlate EF% data's in left ventricle in fetuses with congenital cardiac anomalies and fetuses from mothers with gestational diabetes with good outcome 71 fetuses with diagnosis of fetal cardiac anomalies and 17 fetuses with mothers who had gestational diabetes were included. Planimetric technique was used to calculate EF% in the left ventricles. This technique was made by tracing the endothelial border of the left ventricle. The end of the diastole was assumed just after closure of the mitral valve, just prior to the onset of systole and end of the systole was the minimum cavity size visualized during the cardiac cycle. E/A wave, aortic root, fetal heart rate and diameters longitudinal and transverse of the left ventricle were recorded too. Analysis data's was made by Stata software. Congenital cardiac anomalies EF% mean in left ventricle was reported in 51.93%. Low values 29.5%. Maximum value 84.2% with a standard deviation of 12.8. Mean ejection fraction in left ventricle fetuses with mothers who had gestational diabetes was reported with 55.29% with a low value in 39% and maximum value in 72% and standard deviation in 9.1. The ejection fraction on the fetal left ventricle by planimetric doesn't change neither mothers diabetic compensated nor fetuses with cardiac congenital anomalies. More data's have to be collected to correlated these findings.