Can fetal echocardiograms reliably predict the need for urgent balloon atrial septostomy in transposition of the great arteries?

A term neonate is admitted to the neonatal unit with an antenatal diagnosis of transposition of the great arteries with intact ventricular septum (TGA/IVS) and a 6 mm patent foramen ovale, identified by fetal echocardiogram at 34 weeks gestational age. The preductal and postductal oxygen saturations (SpO2) are 45% and 55% in 100% oxygen. Prostaglandin therapy is commenced at 5 ng/kg/min. In view of unresponsive hypoxaemia, the baby is intubated, mechanically ventilated and prostaglandin dose is escalated to 50 ng/kg/min. However, little improvement in oxygen saturations is noted. You then question the need for urgent balloon atrial septotomy (BAS) although fetal echocardiogram suggested adequate mixing at the atrial connection. In neonates, with an antenatal diagnosis of TGA with IVS or small ventricular septum defect (VSD) (patient), can fetal echocardiogram (intervention) predict the need for urgent BAS (outcome)? Cochrane, Medline, Embase, Cinahl and Maternity and infant care databases were searched on 6 March 2019. The following terms were used: exp ‘INFANT, NEWBORN’/OR (newborn * OR neonates*) AND exp ‘HEART DETECTS, CONGENITAL’/OR (congenital heart AND (defect* OR malformation*)) AND exp ‘ULTRASONOGRAPY, PRENATAL’/OR …