Ultrasound Examination Of The Fetal Ductus Venosus

Objective：The application of color Doppler utrasound to evaluate the ductusvenosus (DV) of fetus. Study on the regular changes of flow velocities wavefoemsfrom the DV of normal fetus by gestational age as well as the abnormal l DV results.Method：Evaluate DV of240normal fetus and90abnormal fetus from eleventh tofortieth week through belly by using the color ultrasonography GE Volusion730.Firstly apply two-dimensional ultrasound to revealed fetal venous catheter on themidline of belly. Then use the color Doppler flow imaging（CDFI）to study the bloodflow signal at the access point of DV which is brighter than peripheral vein with1～2mm sample volume. From the sample, the Doppler flow velocities wavefoems ofDV can be recorded. Finally, the S wave, D wave, A wave maximum speed, and theresistance index (RI), pulsatility index (PI) and S/A ratio of DV could beautomatically measured by the instrument measuring software from Doppler flowvelocities wavefoems of DV within three cardiac cycle when the fetus are in staticstatus. All the data collected is analysised by statistical treatment.Results：Evaluate DV of fetus by using the color Doppler ultrasound, taking themidline of belly as the ideal study sample. In this study, the display rate of DV for thefetus from eleventh to thirty-fifth or thirty-sixth week is as high as100%. And that forthe fetus from thirty-sixth to fortieth week is97.5%. The Doppler flow wavefoems ofDV from normal fetus shows triphasic wave, reflecting ventricular systole(S),ventricular diastole (D) and atrial systole (A). The peak velocity of DV forNormal fetus increases with the growth of gestational age, especially the atrial systole(A). To the opposite, flow index PI, RI, S/a decreased with the growth of gestationalage. And the abnormal DV is closely related to fetal cardiac malformations, nuchalcystic hygroma and chromosome abnormalities.Conclusion：The abnormal flow wavefoems of DV can be seen as one of themarks for the high-risk fetus in early pregnancy and chromosome abnormalities. It isof greater signal action for the abnormal chromosome in early pregnancy than inlate pregnancy. The abnormal DV flow wavefoems is closely related to fetal cardiacmalformations, nuchal cystic hygroma and chromosome abnormalities. The abnormalDV is not related to malformations of the nervous system.The way of color Dopplerultrasound to evaluate DV for feus from eleventh to fortieth week is accurate,simple,easy to operate and could be widely accepted in clinical application...