OC29.03: T‐shaped uterus by Congenital Uterine Malformation by Experts (CUME): suggested definition based on three criteria

To assess the diagnostic test accuracy and the best cut-off values for these measurements in comparison with experts' opinion as reference standard and to define t-shaped uterus. This was a prospectively designed multi-rater reliability/agreement study with elements of diagnostic accuracy study performed between Nov-2017 and Dec-2018 in a sample of 100 3D datasets of different uteri acquired in consecutive women with suspected uterine anomaly due to the presence of lateral uterine cavity indentations between 2014-2016. The diagnostic test accuracy was assessed using the area under ROC curve (AUROC) and the best cut-off value was assessed using Youden's index, using the most voted option by the 15 experts as the reference standard. We determined sensitivity (Se), specificity (Sp), negative and positive-likelihood ratio (LR- and LR+) and positive predictive value (PPV). There were 20 t-shaped and 80 normal/arcuate uteri using CUME as reference standard (≥ 8 votes). We identified three measurements with good diagnostic test accuracy: lateral indentation angle (AUROC = 0.95), lateral indentation depth (AUROC = 0.92), and t-angle (AUROC = 0.87). The best cut-offs values for these measurements were: lateral indentation angle ≤ 130° (Se = 75%, Sp = 96%, LR- = 0.21, LR+ = 21, PPV = 83%), lateral indentation depth ≥ 7 mm (Se = 85%, Sp = 78%, LR- = 0.06, LR+ = 4.2, PPV = 49%), and t-angle ≤ 40° (Se = 65%, Sp = 91%, LR- = 0.23, LR+ = 6.4, PPV = 64%). 56 women had no criteria (all = normal/arcuate), 20 had only one criterion (PPV = 10%), 10 had only two criteria (PPV = 50%) and 14 had all the three criteria (PPV = 93%). Lateral indentation depth ≥ 7 mm, lateral indentation angle ≤ 130° and t-angle ≤ 40° might be used for the diagnosis of t-shaped uterus when there is any suspicious by subjective assessment. We suggest considering 0-1/3 criteria = normal/arcuate, 2/3 criteria = borderline t-shape, and 3/3 criteria = definitely t-shaped uterus.