Fetal cardiovascular magnetic resonance may offer prenatal diagnostic information for indeterminate congenital heart defects

1. The majority of prenatal fetal cardiovascular magnetic resonance (CMR) imaging improved the diagnosis of congenital heart defects (CHD) when fetal echocardiography yielded inconclusive result.

2. CMR findings led to a change in patient management or parental counselling in the majority of cases.

Evidence Rating Level: 2 (Good)

Study Rundown: Congenital heart defects (CHD) are a significant cause of infant morbidity and mortality. Prenatal diagnosis of CHD improves outcomes by altering mode of delivery and planning for postnatal care. This study investigated the clinical utility of prenatal fetal cardiac magnetic resonance (CMR) imaging for suspected CHD cases that were inconclusive on prenatal fetal echocardiography. CMR findings were compared to postnatal outcomes and postnatal echocardiography findings. Overall, in 26 out of 31 patients, fetal CMR provided additional information that altered the delivery plan, changed patient management, and/or affected parental counselling regarding expected postnatal outcomes and treatments. Prenatal fetal CMR may be a valuable diagnostic tool for uncertain CHD cases in-utero. One strength of this study was the utilization of three different observers to evaluate all fetal CMR images. This study, however, was limited since it was single-centred, reducing the generalizability of its findings. Furthermore, no statistical analysis was completed to determine CMR’s accuracy in predicting postnatal outcomes; this was likely due to the small sample size available.

Click to read the study in JAMA

Click to read an accompanying editorial in JAMA

Relevant Reading: Dynamic fetal cardiovascular magnetic resonance imaging using Doppler ultrasound gating

In-Depth [prospective cohort]: Patients from Skåne University Hospital (Lund, Sweden) were prospectively enrolled between January 20, 2017, and June 29, 2020. Patients underwent routine ultrasound screening, and those with suspicion of CHD received fetal echocardiography. 31 fetuses with inconclusive prenatal echocardiography findings were included in the study and underwent CMR at gestational age 36 (range: 31-39) weeks. CMR findings modified patient management or parental counselling in 15 out of 20 cases with aortic arch abnormalities, in 10 out of 15 cases who showed signs of borderline left ventricle, pulmonary atresia with intact ventricular septum, or unbalanced atrioventricular septal defect, in 3 out of 4 cases with hypoplastic left heart syndrome, and in 2 out of 3 cases with other abnormalities. Overall, CMR altered management or counselling in 26 out of 31 patients (84%). There were 2 incidences where fetal CMR incorrectly predicted postnatal outcomes.

Image: PD

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