Vorstellung einer neuen Methodik zur Visualisierung typischer Befundkonstellationen für euploide und aneuploide Feten – Common Bubbles im AFS–3D-Verfahren

Aneuploidy screening during pregnancy by a three-dimensional Advanced First Trimester Screening model: description of the AFS-3D algorithm

BACKGROUND

A novel screening method for fetal aneuploidies was developed, in which nuchal translucency (NT), pregnancy-associated plasma protein-A (PAPP-A), and free-β human chorionic gonadotropin (free-β hCG) are placed into a three-dimensional scatter plot. Likelihood ratios are directly inferred from the ratio of already observed healthy and diseased fetuses. This method is called 'Three-dimensional Advanced First trimester Screening' (AFS-3D). It was aimed to develop and test a new algorithm based on the results of previous studies.

METHODS

A new static-sized sphere model was developed. Several scaling factors of the axes and the optional application of the modifications 'simulation' (SIM) and 'empty sphere positive' were tested on 15,227 data sets. An additional examination was performed on a second collective (n = 458).

RESULTS

The application of the new AFS-3D model with static-sized spheres, a re-sampled ∆NT axis by a scaling factor of 0.125, and the application of SIM and Empty Box Positive resulted in a marked improvement of the test performance (area under curve, AUC = 0.9668). Analogous results (AUC = 0.9807) were found for the second test collective.

CONCLUSIONS

This novel approach is promising and should be tested on a larger, independent collective.