Risk Factors for Adverse Outcome in Fetuses With Heterotaxy Syndrome and Congenital Heart Disease

Objective Fetuses with heterotaxy syndrome and congenital heart disease have high morbidity and mortality. We sought to identify risk factors impacting survival in the current era. Method Retrospective, single center cohort study of fetuses diagnosed with heterotaxy syndrome and congenital heart disease between January 2005 and December 2023. Prenatal echocardiographic parameters and clinical outcomes were recorded. Findings were compared between the right and left atrial isomerism subtypes. Univariate and multivariable logistic regression were utilized to identify prenatal variables predictive of fetal demise. Postnatal survival was examined with Kaplan‐Meier curves and univariate Cox proportional hazard models. Results The cohort consisted of 197 subjects: 97 with right atrial isomerism and 100 with left atrial isomerism. Median 5‐ and 10‐year survival was 71% (95% CI 64–80) and 68% (95% CI 60–77). Fetuses with left atrial isomerism had higher survival ( p = 0.028). In multivariable analysis, complete heart block (CHB) ( p < 0.001) and ventricular dysfunction ( p = 0.043) predicted fetal demise, whereas pulmonary venous obstruction ( p = 0.002) and CHB ( p < 0.001) predicted postnatal mortality. Major extra‐cardiac congenital anomaly did not influence postnatal survival ( p = 0.7). Conclusion CHB and pulmonary venous obstruction remain significant predictors of postnatal mortality in fetuses with concurrent heterotaxy syndrome and congenital heart disease.