Cumulative sum plots and retrospective parameters in first-trimester ductus venosus quality assurance

ABSTRACT Objective This study aimed to evaluate the application of two quality assurance methods to the ductus venosus pulsatility index (DVPI), as a first‐trimester aneuploidy marker, including retrospective assessment of distribution parameters and cumulative sum (CUSUM) plots. Methods The DVPI was measured in 14 444 singleton fetuses at 11+0 to 13+6 weeks in two Fetal Medicine centers during a 4‐year period. Sonologist‐specific quality assurance distribution parameters, previously described for nuchal translucency, were assessed: the median multiples of the median (MoM), the logarithmic standard deviation of DVPI MoMs and the weekly DVPI percent decrease. Quality assurance results were compared between median MoMs and MoM‐based CUSUM plots. Results When sonologist‐specific DVPI distribution parameters were retrospectively applied for quality assurance, a 1.0 median MoM, a 0.1 median logarithmic standard deviation and a 3.4 median weekly DVPI drop percentage were observed. CUSUM plots showed good agreement with 0.9–1.1 MoMs range for median MoM, in the assessment of sonologist‐specific performances. Conclusion Retrospective and prospective DVPI quality assurance methods appear to be applicable to DVPI at 11+0 to 13+6 weeks. Its use should be encouraged if DVPI is to be added to first‐trimester Down syndrome or cardiac defects screening. © 2013 John Wiley & Sons, Ltd. What's already known about this topic? The addition of DVPI improves first‐trimester screening results. Quality assurance of sonographic markers is crucial to achieve a correct screening performance. What does this study add? Retrospective quality assurance parameters used for other markers can be applied to DV. A model of MoM‐based DV CUSUM plots to prospectively assess sonologist‐specific performance is proposed.