[Redistribution of fetal cardiac output in intrauterine growth retardation]

One hundred and thirty-one fetuses with a gestational age between 29 and 41 weeks have been studied by Doppler-Echocardiography. The cases include normal pregnancies and those with a risk for congenital heart disease. We compared the cardiac output distribution, calculated by Pulsed Doppler-Echocardiography, between the intrauterine growth retardation cases and those with normal growth. The normal and relative dominance of the right versus the left ventricle is demonstrated in normal pregnancies and normal growth fetuses. This ratio is clearly inverted in the growth-retarded cases. This redistribution of blood flow may be a response to chronic hypoxia allowing preferential flow of the blood to the brain.