Utility of Fetal Cardiovascular Magnetic Resonance for Prenatal Diagnosis of Complex Congenital Heart Defects

Key Points

Question

Does fetal cardiovascular magnetic resonance improve prenatal diagnosis of complex congenital heart defects when fetal echocardiography is insufficient?

Findings

In this cohort study of 31 fetuses referred for fetal cardiovascular magnetic resonance imaging, additional clinically useful information regarding cardiovascular anatomy and function was obtained in 84% of referred cases, covering a wide spectrum of congenital heart defects. This information affected choice of mode of delivery, planning of early postnatal care, and parental counseling.

Meaning

These findings suggest that fetal cardiovascular magnetic resonance imaging can add important diagnostic information and affect clinical decision-making and parental counseling.

Abstract

This cohort study assesses the clinical utility of fetal cardiovascular magnetic resonance imaging when fetal echocardiography could not visualize all relevant anatomy.

Abstract

Importance

Prenatal diagnosis of complex congenital heart defects reduces mortality and morbidity in affected infants. However, fetal echocardiography can be limited by poor acoustic windows, and there is a need for improved diagnostic methods.

Objective

To assess the clinical utility of fetal cardiovascular magnetic resonance imaging in cases in which fetal echocardiography could not visualize all relevant anatomy.

Design, Setting, and Participants

This cohort study was conducted between January 20, 2017, and June 29, 2020, at Skåne University Hospital (Lund, Sweden), a tertiary center for pediatric cardiology and thoracic surgery. Participants were fetuses referred for fetal cardiovascular magnetic resonance examination by a pediatric cardiologist after an inconclusive echocardiograph.

Exposures

Fetal cardiovascular magnetic resonance examination requested by the patient’s pediatric cardiologist.

Main Outcomes and Measures

Any change in patient management because of diagnostic information gained from fetal cardiovascular magnetic resonance imaging.

Results

A total of 31 fetuses underwent cardiovascular magnetic resonance examination at a median gestational age of 36 weeks (range, 31-39 weeks). Overall, fetal cardiovascular magnetic resonance imaging had clinical utility, affecting patient management and/or parental counseling in 26 cases (84%). For aortic arch anatomy including signs of coarctation (20 fetuses), fetal cardiovascular magnetic resonance imaging added diagnostic information in 16 cases (80%). For assessment of univentricular vs biventricular outcome in borderline left ventricle, unbalanced atrioventricular septal defect, and pulmonary atresia with intact ventricular septum (15 fetuses), fetal cardiovascular magnetic resonance imaging visualized intracardiac anatomy and ventricular function, allowing assessment of outcome in 13 cases (87%). In 4 fetuses with hypoplastic left heart syndrome, fetal cardiovascular magnetic resonance imaging helped delivery planning in 3 cases (75%). Finally, fetal cardiovascular magnetic resonance imaging provided valuable information for parental counseling in 21 cases (68%).

Conclusions and Relevance

In this cohort study, fetal cardiovascular magnetic resonance imaging added clinically useful information to what was available from echocardiography. These findings suggest that fetal CMR has the potential to affect clinical decision-making in challenging cases of congenital heart defects with inconclusive data from echocardiography. Fetal cardiovascular magnetic resonance imaging showed an association with clinical decision-making, including mode of delivery and early postnatal care, as well as with parental counseling.