VP37.07: Physiological variability of ductus venosus pulsed‐wave Doppler indices: a pilot study

Despite the near ubiquitous use of pulsed-wave Doppler (PWD) derived-indices as diagnostic tools in clinical practice, the impact of physiological variability upon them has never been clearly documented. Of the PWD ductus venosus (DV) indices, there is no consensus on which to use for clinical management in late gestation. We aimed to report and evaluate the variability of DV PWD derived-indices. 20 healthy, singleton pregnant women at 20 to 37 weeks' gestational age (GA) were recruited. 40 PWD waveforms were stored from each for DV, using a GE Voluson E8 and 2D convex transducer (C4-8D) with machine settings set to ISUOG Doppler guidelines. For each single waveform, systole/atrial contraction ratio (S/a), pulsatility index venosus (PIV), preload index (PLI) and peak velocity index for vein (PVIV) were automatically measured. Coefficient of variation (CoV) was calculated for each index and was linearly regressed versus GA using correlation coefficients (r). 19 patients (95%) provided full data. All indices demonstrated CoV >10% over the study time; S/a showed lowest and PVIV greatest variation across all indices evaluated. There was a range of correlation (r) between the CoV for the indices and gestational age (PVIV = -0.7; PLI = 0.15; PIV = 0.1; S/a = -0.3). All DV PWD indices showed high variability; least for S/a and PLI. S/a variability decreases with GA, potentially representing the best index in terms of variability for late pregnancy evaluation. Physiological variability may account for 11–15% of DV PWD indices values, therefore they should be interpreted with caution in clinical practice. Further studies to assess the relationship between these indices and clinical applicability should be encouraged to define the most reliable DV index.