DUCTUS VENOSUS REVISITED - A DOPPLER BLOOD-FLOW EVALUATION IN THE FIRST TRIMESTER OF PREGNANCY

The functional role of the fetal ductus venosus (DV) is still poorly e stablished, Few reports are available in the literature concerning ass essment of fetal venous return during the late first trimester of preg nancy, Our objective was to determine the normal Doppler blood velocit y waveform in the human fetal DV as early as 10-13 weeks gestation. Ad opting strict methodological concerns, 61 Doppler blood flow evaluatio ns of the DV considered technically acceptable were selected. Using tr ansvaginal Doppler ultrasound, several DV haemodynamic parameters were assessed: peak systolic and diastolic velocities, time-averaged veloc ity, maximum velocity during atrial contraction, pulsatility index and fetal heart rate (FHR). Except for the FHR, no significant variations were observed for the above mentioned parameters during this period, and no correlation could be established between FHR and the different flow velocity parameters, Further knowledge about DV haemodynamics in the early phases of pregnancy may make a valuable contribution to the understanding of fetal venous return to the heart and cardiac function . (C) 1997 World Federation for Ultrasound in Medicine & Biology.