Prenatal sonography of the foramen ovale predicts urgent balloon atrial septostomy in neonates with complete transposition of the great arteries.

Abstract Background Hypoxia caused by inadequate intracardiac mixing due to a restrictive foramen ovale (FO) is a potentially life-threatening complication in neonates with transposition of the great arteries (dTGA). An urgent balloon atrial septostomy (BAS) is a procedure of choice in such cases, but dependent on the availability of a 24-hour interventional cardiology facility. The prenatal identification of predictors for an urgent BAS at birth would help in optimizing the management of these neonates, minimizing the risk of hypoxic damage. Objective to predict with prenatal echocardiography the need of urgent BAS in neonates with dTGA. Study design this was a retrospective cohort study of patients with a prenatal diagnosis of TGA that were delivered in our center between 2010 and 2019, for whom fetal ultrasound echocardiograms obtained less than three weeks before delivery were available. The following parameters were systematically obtained at fetal echocardiography: size and appearance of FO, septum primum excursion (FO flap angle at the maximal excursion), diameters of the atria, size of the ductus arteriosus. BAS was defined as urgent if performed within 12 hours from birth in neonates with restrictive foramen ovale. Neonatal follow-up was obtained through medical records analysis. Results From November 2007 to April 2019, 160 fetuses with complete TGA were referred to our echocardiography laboratory and 60 of these were included in the analysis; 27 underwent urgent BAS, 11 elective BAS and 22 no BAS. The size of the FO was the best predictor of a urgent BAS. A measurement > 6.5 mm had a sensitivity of 100% and a false positive rate of 45%. Conclusion Fetal echocardiography predicts the need of a urgent BAS in fetuses with dTGA although with a limited precision. In our experience a measurement of the FO within three weeks of delivery had the greatest accuracy.