P19.02: Procedural and obstetrical outcomes of amniocentesis or chorionic villus sampling in dichorionic twin pregnancies

diagnosis of two diseases were searched and the diagnostic value was evaluated. Results: Quantile (Q) value of the internal diameter of the aorta (AO Q-score), the ratio of the diameter of the pulmonary artery to the internal diameter of the aorta (PA/AO), and Q value of the ratio of the diameter of the pulmonary artery to the internal diameter of the aorta (PA/AO Q-score) were the key parameters for the differential diagnosis of fetal large VSD and TOF. PA/AO is the primary parameter, which area under the curve (AUC) of PA/AO is 0.951. The mean value of PA/AO in normal fetuses was 1.22, in fetuses with large VSD was 1.21, and in TOF fetuses was 0.49. If we set the threshold of two differential diagnosis of PA/AO to 0.89, then the diagnostic sensitivity can be guaranteed more than 90% in range of false positive rate of 10%. Conclusions: The accuracy of ultrasonic diagnostic parameters of large VSD and TOF is high by medical data statistics and big data analysis. It provides a new way for prenatal diagnosis of large VSD and TOF.