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.