This study was carried on 52 pregnant females. The studied sample was dividing: according to the gestational ages into four groups: namely 20-25 weeks, 26-30 weeks 36-40 weeks. The present study entails ecchocardioaphy measurement of the fetal cardiac output at the various phases of intra uterine life. The results showed a progressive significant increase in the stroke volume with the advance in gestational age. Also it was observed that the advance of gestational age was accompanied with a gradual significant deceleration of the fetal heart rate. Despite the deceleration of the fetal heart rate with the advance of the gestational age, the present study clearly showed a gradual highly significant increase in the fetal cardiac output. The fetal cardiac outpt is affected only by the gestational age and not by the fetal sex.