Abnormal ductus venosus pulsatility index in the absence of concurrent umbilical venous pulsations does not indicate worsening fetal condition.

OBJECTIVE: Recordings of blood flow velocity waveform in the ductus venosus (DV) and the umbilical vein (UV) are routinely used in order to predict the fetal condition in high-risk pregnancies. This study investigates the relationship between pathological blood flow in the two vessels and perinatal outcome. METHODS: High-risk pregnancies (n=11865) admitted during 1993-2011 for blood flow examinations, including recordings of DV pulsatility index for veins (PIV) and UV pulsations, were included. The results were related to perinatal outcome, using the last Doppler examination prior to delivery in analysis. RESULTS: Abnormal DV PIV was observed in 3,96%, intra-abdominal UV-pulsations in 1,3% and pulsations in the cord in 0,7% of the cases. As expected, the rate of UV-pulsations increased with increasing DV PIV z-score. Fetuses with a pathological DV PIV, but without UV pulsations showed no signs of compromise. This was also true for cases with a DV PIV >4 SD above the mean (53.7 % had a steady flow in the UV). In contrast, the occurrence of UV-pulsations seems to be an indicator of fetal compromise regardless of level of DV PIV. CONCLUSIONS: Abnormal fetal venous blood velocity is related to adverse outcome of high-risk pregnancies. However, abnormal DV PIV is not an indicator of fetal compromise unless UV-pulsations are concurrently present and should be regarded as an artifact and not an indication for emergency delivery.