[The evaluation of umbilical arterial Doppler spectrum fractal characterization in obstetrics]

To evaluate the clinical value of fetal umbilical arterial Doppler spectrum fractal.

104 cases with 22-41 gestational weeks were included, and divided into two groups: normal pregnant group, 59 cases; abnormal pregnant group, 45 cases. Umbilical arterial Doppler spectrum were obtained by color Doppler ultrasound, then Doppler signal were transformed into computer through sound-frequency, and fractal were calculated.

The fractal was 1.83 +/- 0.03 in normal pregnant group. The frequency of abnormal fractal was significantly higher in abnormal pregnant group than that in normal pregnant group (P < 0.001). Compared with the ratio of peak systolic to lowest diastolic flow velocity (S/D), the fractal was more sensitive than S/D ratio in abnormal pregnancy (P < 0.05). There were significant correlation between fractal and gestational weeks (r = 0.266).

Fractal responses to complexity of umbilical arterial blood flow, and it is a better parameter than S/D ratio in monitoring abnormal umbilical arterial blood flow.