Heterotaxy syndrome: Prenatal diagnosis, concomitant malformations and outcomes

The aim of this study is to define cardiac and extracardiac malformations in fetuses with heterotaxy syndrome and to determine perinatal and childhood prognosis.In this retrospective study, fetuses diagnosed with heterotaxy syndrome on antenatal ultrasonography in a tertiary center between January 2014 and January 2021 were analyzed. Fetuses with heterotaxy syndrome were grouped as right atrial isomerism (RAI) and left atrial isomerism (LAI).A total of 62 fetuses, 32 (51.6%) with RAI and 30 (48.4%) with LAI, were included in the study. Extracardiac anomaly was detected in 25% of fetuses with RAI and 44% of fetuses with LAI (p = 0.13). Patients with univentricular repair had a higher childhood mortality than patients with biventricular repair (p = 0.031). The presence of conotruncal anomaly was an independent factor affecting mortality (HR = 5.09, CI 95% 1.09-23.71, p = 0.039).Hydrops fetalis, univentricular physiology and conotruncal anomalies are associated with poor outcomes in heterotaxy syndrome. The severity of the cardiac malformation is the main determinant of the outcomes. The presence of extracardiac malformations is associated with increased morbidity and mortality.