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

Abstract

Recordings of blood flow velocity waveforms in the ductus venosus (DV) and umbilical vein (UV) are routinely used in order to predict fetal condition in high-risk pregnancies. The aim of this study was to investigate the relationship between pathological blood flow in the two vessels and perinatal outcome. High-risk pregnancies (n = 11 863) admitted from 1993 to 2011 for blood-flow examination, including recordings of DV pulsatility index for veins (DV-PIV) and UV pulsations, were included. The results were related to perinatal outcome, using the last Doppler examination prior to delivery in the analysis. Abnormal DV-PIV was observed in 3.9% of cases, intra-abdominal UV pulsations in 1.3% and pulsations in the cord in 0.7%. 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 fewer signs of compromise. This was also true for cases with a DV-PIV ≥ 4 SDs above the mean (53.7% had steady flow in the UV). In contrast, the occurrence of UV pulsations seemed to be an indicator of fetal compromise, regardless of level of DV-PIV. Abnormal fetal venous blood velocity is related to adverse outcome in high-risk pregnancies. However, abnormal DV-PIV is not a reliable indicator of fetal compromise unless UV pulsations are concurrently present, and should not be regarded an indication for emergency delivery.