[Doppler echocardiographic studies on the fetal cardiac function in intrauterine growth retardation]

To assess fetal cardiac function by Doppler echocardiography in intrauterine growth retardation (IUGR).

We investigated the changes in cardiac function in 64 normal fetuses and 36 fetuses with IUGR. Blood flow velocity waveforms were obtained from the aorta, pulmonary artery and atrioventricular valves. The following variables were measured: peak flow velocity (PFV), mean velocity (V), accelerate time (ACT), systolic volume (SV) and cardiac output (CO) represented the systolic function; the peak early flow velocity (PFVe), peak late flow velocity (PFVa), PFVe/PFVa (E/A), mean velocity (V) of mitral or tricuspid valve represented the diastolic function.

In normal fetuses, the PFV, V, ACT of aorta were all greater than those of pulmonary artery, whereas SV, CO in left ventricle were smaller. The PFVe, PFVa in mitral valve were smaller than those of tricuspid valve. In IUGR fetuses, the PFV, V, SV, CO of aorta or pulmonary artery were significantly lower than those of normal. The ACT in pulmonary artery decreased significantly, but increased in aortic artery. The SV, Co of left ventricle were greater than those of righ ventricle. The E/A of mitral and tricuspid valve, PFVe, PFVa, V of tricuspid valve were all decreased. The PFVe, PFVa in mitral valve were greater than those of tricuspid valve.

The changes of cardiac function in IUGR are probably caused by "brain sparing", which means a redistribution of cardiac flow after hypoxia.