A preliminary study of fetal ductus venosus blood flow during the first stage of labor

Objective: The measurement of fetal ductus venosus blood flow during labor by means of color Doppler sonography. Methods: 26 women between 37 and 41 weeks of gestation were included in the study. At various stages of cervical dilation (<2 cm, 2-4 cm, 6-8 cm, and fully dilated) blood flow velocity waveforms of the fetal ductus venosus during and between contractions were studied in fetuses with a negative non-stress test. The Pulsatility index for veins (PIV) and the Peak velocity index for veins (PVIV), respectively were calculated off-line. The mean±standard deviation between and during contractions were determined for descriptive analysis. Results: Waveforms were visualized during 139 contractions and 159 episodes of uterine relaxation in 24 of 26 fetuses (92.3%) in normal labor. Three and more waveforms were recorded, in 59.0% during contractions (82/139) and in 57.9% between contractions (92/159), respectively. The mean PIV and PVIV values during contractions were 1.68±1.02 and 1.46±0.72, respectively. Between contractions the values were 0.49±0.21 for the PIV and 0.44±0.18 for the PVIV, respectively. Conclusion: Ductus venosus blood flow can be visualized in labor. Further studies are needed to establish normal values.