Prenatal diagnosis of prevalence of the right heart: associated anomalies and outcome predictors

Objectives: To analyze the characteristics, associations, and outcomes of prevalence of the right heart and to evaluate the use of sonography to predict the risk of a poor prognosis in fetuses with this condition.

Methods: We conducted a retrospective cohort study of 182 fetuses with prevalence of the right heart. At the initial evaluation, the left ventricle (LV) and right ventricle (RV) sizes, left atrium and right atrium sizes, great artery diameters, appearance of the aortic arch and ductus arteriosus arch, and flow direction across the foramen ovale and aortic arch were documented. Malformations were documented in fetuses with intracardiac anomalies, who were divided into groups with and without coexisting extracardiac defects. The RV-LV diameter ratio and main pulmonary artery-to-aortic root diameter ratio were calculated and compared. The following variables were analyzed: coexisting intracardiac anomalies, associated extracardiac anomalies, diagnosis before 24 gestational weeks, fetal growth restriction, reversed flow across the foramen ovale, reversed flow in the aortic arch, and RV-LV ratio greater than 2.0. Relationships between these sonographic findings and the prognosis were evaluated by multivariable logistic regression.

Results: Of the 182 fetuses, 1 (0.5%) had intrauterine death, and 25 (13.7%) had neonatal death; 1 (0.5%) had selective reduction, and 106 (58.2%) underwent termination of pregnancy; 49 (26.9%) survived at this writing. The mean RV-LV ratio was 1.67. Multivariable logistic regression revealed that only 2 sonographic parameters, coexisting intracardiac anomalies (odds ratio, 17.75; 95% confidence interval, 4.18-75.26) and diagnosis before 24 weeks (odds ratio, 17.26; 95% confidence interval, 1.80-165.39) were significantly associated with a poor prognosis.

Conclusions: The sonographic parameters of coexisting intracardiac anomalies and diagnosis before 24 gestational weeks are significant independent predictors of a poor prognosis in fetuses with prevalence of the right heart. Combinations of these risk factors may be useful in prenatal consultation.