Enhancing Prenatal Diagnosis of Obstructive Aortic Arch Abnormalities: Evaluating the Role of the Longitudinal Visualization Techniques

Abstract Background: This study aimed to evaluate whether visualization of the longitudinal plane of the fetal thoracic arch could enhance the diagnostic accuracy of obstructive aortic arch (AoA) abnormalities. Methods: This retrospective study was conducted at a perinatal center. Eleven newborns diagnosed with obstructive AoA abnormalities were examined, with a focus on fetal position during fetal echocardiography. Results: Fetal positions were grouped into positions 1 (insonating from the left dorsal side of the fetal spine) and 2 (difficulty insonating from the left dorsal side). Out of 33 fetuses positioned in the uterine cavity at position 1, six were diagnosed with obstructive AoA abnormalities after birth. Three newborns had a coarctation complex, which matched the fetal echocardiographic findings. Out of 51 fetuses positioned in the uterine cavity at position 2, five were diagnosed with obstructive AoA abnormalities after birth. Four newborns had obstructive AoA abnormalities inconsistent with prenatal diagnosis. The odds ratio of the visualization rates for the longitudinal plane of obstructive AoA from position 1 was 41.67 compared to position 2. Obstructive AoA abnormalities were more frequently diagnosed in position 1 (50%) than in position 2 (20%) during fetal echocardiography. Conclusion: When performing fetal echocardiography, scanning the patient from the left posterior side of the fetal spine parallel to the fetal transverse arch is helpful for visualizing fetal AoA morphologies. Prospective studies with large sample sizes are further needed to enhance the diagnostic rates of obstructive AoA abnormalities using fetal echocardiography.