Modulation of echocardiographic parameters by fetal behaviour

In order to verify if fetal behavioural states could affect cardiac parameters, thirty‐one healthy fetuses were studied near term. We evaluated systolic time intervals (pre‐ejection period and ventricular ejection time), M‐mode parameters (fractional shortening and mean circumferential shortening) and Doppler flow velocities (mean peak velocity of aortic and pulmunary arteries) of left and right ventricles. Both fetal breathing movements and fetal heart rate patterns seem to modify these parameters with an increase of cardiac contractility during active phases of fetal behaviour.