Vol.:(0123456789) 1 3 Pediatric Cardiology (2021) 42:1575–1584 https://doi.org/10.1007/s00246-021-02642-w ORIGINAL ARTICLE Reliability of Fetal Echocardiography in Predicting Postnatal Critical Hypoxia in Patients with Transposition of Great Arteries and Intact Ventricular Septum M. Masci 1  · L. Pasquini 1  · T. Alsaied 2  · L. Di Chiara 3  · R. Formigari 4  · L. Galletti 5  · C. M. Campanale 1  · A. Romiti 6  · M. Bonito 7  · P. Bagolan 8  · A. Toscano 1 Received: 16 January 2021 / Accepted: 18 May 2021 / Published online: 29 May 2021 © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2021 Abstract Critical hypoxemia soon after birth is the most critical preoperative determinant of neurological outcomes and survival in newborns with Dextro Transposition of the Great Arteries and Intact Ventricular Septum (D-TGAIVS). Our study aimed to defne fetal echocardiographic aspects that can better predict neonates with D-TGAIVS at risk for restricted interatrial com- munication after birth. 31 fetuses with a prenatal diagnosis of D-TGAIVS were included in our study. We divided patients with D-TGAIVS according to the timing of balloon atrial septostomy: Urgent, Not-Urgent and no BAS. We identifed fve fetal echocardiographic aspects of the interatrial septum (redundant, aneurysmal, fat, fxed, hypermobile). No signifcant diferences in these fetal echocardiographic features were found between the three diferent groups of D-TGAIVS according to the timing of balloon atrial septostmy. However, only two patients showed fat appearance of interatrial communication: both needed Urgent balloon atrial septostomy. The prevalence of hypermobile septum primum was signifcantly lower in the control group compared to patients with D-TGAIVS. Fetal echocardiographic aspects cannot predict patients with D-TGAIVS who will not need Urgent balloon atrial septostomy. Therefore, we recommended a delivery in a tertiary center, equipped for Urgent balloon atrial septostomy, for all patients with D-TGAIVS regardless of fetal echocardiographic features. Keywords Fetal echocardiography · Transposition of the great arteries · Restrictive atrial septum · Balloon atrial septostomy * L. Pasquini luciano.pasquini@opbg.net 1 Perinatal Cardiology Unit, Department of Medical and Surgical for Fetus-Neonate, Bambino Gesù Children’s Hospital IRCCS, Rome, Italy 2 Heart Institute Department of Pediatrics, Cincinnati Children’s Hospital Medical Center University of Cincinnati, Cincinnati, OH, USA 3 Pediatric Cardiac Intensive Care Unit, Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy 4 Cardiac Hemodynamics Unit, Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Children Hospital-IRCSS, Rome, Italy 5 Pediatric Cardiac Surgery Unit, Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy 6 Fetal Medicine and Surgery Unit, Department of Medical and Surgical for Fetus-Neonate, Bambino Gesù Children’s Hospital IRCCS, Rome, Italy 7 Department of Obstetrics and Gynecology, San Pietro Fatebenefratelli Hospital, Rome, Italy 8 Neonatal Surgery Unit, Department of Medical and Surgical for Fetus-Neonate, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy