Utility of serial fetal echocardiograms in detecting in-utero changes for single-ventricle lesions: an 11-year...

Current guidelines in fetal echocardiography recommend serial evaluation every 4 weeks for single-ventricle lesions. However, there are limited data on the type and frequency of in-utero cardiac changes seen on fetal echocardiograms (FEs) based on the type of single-ventricle lesion. We aimed to evaluate the utility of serial FEs in detecting cardiac changes during gestation and how these changes impact postnatal management.

We performed a retrospective review of all FEs for fetuses diagnosed with a single-ventricle lesion at the Children's Healthcare of Atlanta, between January 2012 and January 2023. All patients included in the study had two or more FEs and were evaluated for in-utero cardiac changes based on eight cardiac categories: atrioventricular (AV) valve regurgitation; systemic ventricular dysfunction; ductus arteriosus flow; atrial-level restriction; umbilical artery Doppler pattern; umbilical vein Doppler pattern; evidence of hydrops; and evidence of arrhythmias. All in-utero cardiac changes were classified into three categories: improving, worsening or critical. Any changes noted on serial FEs that altered the fetal cardiac diagnosis were also recorded. Fisher's exact test was used to determine whether the proportion of fetuses with in-utero cardiac changes differed significantly between different segmental findings and single-ventricle lesion subtype.

A total of 721 FEs were performed for 248 patients over the 11-year study period. The majority of fetuses had hypoplastic left heart syndrome (HLHS) (63.7%) and most changes were seen in the third trimester (median gestational age, 29.3 (range, 17.4-38.4) weeks). In-utero cardiac changes observed on serial FEs were reported in 38 (15.3%) fetuses, with a total of 42 changes noted throughout the study period. However, only eight (3.2%) fetuses had a critical change that impacted perinatal management. All eight fetuses had HLHS, of which the majority developed hydrops (4/8) or atrial-level restriction (3/8). In addition, there were 34 non-critical changes seen in 30 (12.1%) fetuses, largely in the form of intermittent premature atrial contractions, AV valve regurgitation or ventricular dysfunction. There were 12 (2.5%) follow-up FEs that resulted in a change to the fetal cardiac diagnosis, confirmed by postnatal echocardiography.

In fetuses with single-ventricle lesions, there was a low rate of in-utero cardiac changes that led to alterations in perinatal management. However, fetuses with HLHS were most likely to develop critical changes affecting delivery-room management, often in the form of atrial-level restriction and/or evolving hydrops. It is important to consider these factors when considering the timing of visits for families who face a prenatal diagnosis of a single-ventricle lesion. © 2025 International Society of Ultrasound in Obstetrics and Gynecology.