Doppler flow velocity waveforms in the fetal ductus arteriosus during the first half of pregnancy: a reproducibility...

Reproducibility of flow velocity waveform measurement in the fetal ductus arteriosus was studied in 52 normal pregnancies between 11 and 25 weeks of gestation. The flow velocity parameters studied were the peak systolic velocity, mean velocity, end-diastolic velocity, flow velocity integral and acceleration time. In each woman two consecutive measurements were performed with a time delay of 15 min. An acceptable reproducibility was achieved for all flow velocity parameters, except for the acceleration time and end-diastolic velocity.