Abstract: Objective: To detect the blood flow sepectrum of fetal ductus venosus (DV) with colorDoppler ultrasound, and to explore the application of the fetal DV in screening the chromosome abnormalities.Methods: The blood flow spectra of fetal DV in antenatal examination normal group (320 cases, with 11-40 weeks of gestation) and antenatal examination abnormal group (48 cases, within 11-35 weeks of gestation) were detected with color Doppler and pulse Doppler ultrasound, and chromosome examination was performed in abnormal group. The fetal DV blood flow patterns (S wave, D wave, a wave) were observed, and karyotype analysis was performed in abnormal group.Results: The normal Doppler spectrum of the DV in fetuses showed the same three-phase waves while the abnormal Doppler spectrum of the DV in fetuses showed a wave reserved or absented.A total of 48 cases of chromosome in abnormal group were examined; 12 cases of chromosome abnormality were found in this study (10 cases of DV abnormality and 2 cases of DV normality).A total of 36 cases of normal chromosomes were found which (11 cases of abnormal DV and 25 cases of normal DV).The abnormal detection rate of DV blood flow spectrum in chromosome abnormal group was higher than that in chromosome normal group (χ²=9.723,P=0.002).Conclusion: The abnormality of fetal DV blood flow spectrum can increase the detection rate of chromosome abnormalities and ultrasonography could be used as the primary basis for screening the chromosome abnormality in early pregnancy.

Key words: ductus venosus, chromosome, hemodynamics, fetus