Utility of Screening Fetal Echocardiograms Following Normal Level II Ultrasounds in Fetuses with Siblings with Congenital Heart Disease

INTRODUCTION: In pregnancies when congenital heart disease (CHD) is present in siblings, fetal echocardiograms (F-echo) are recommended, regardless if there was a prior level II ultrasound (LII-US) that was normal. The goal of this study was to evaluate if any diagnosis of a critical congenital heart disease (CHD) was missed in a fetus who had a sibling with CHD, when a normal LII-US was documented. METHODS: Retrospective chart review of all F-echo where the indication was sibling with CHD between January 1, 2019 and December 31, 2023 was performed. Fetuses were included if they had a LII-US that was read as normal and had a F-echo. Critical CHD was defined as CHD requiring catheterization or surgical intervention < 1 month of age. RESULTS: A total of 187 F-echo on fetuses who had a sibling with CHD were evaluated, of which 113 met inclusion criteria. LII-US was performed at 21.1 ± 3.3 weeks gestational age and F-echo was performed at 25.4 ± 3.1 weeks gestational age. No patient with a normal LII-US had a diagnosis of a critical CHD by F-echo (negative predictive value = 100%). Six patients that had a negative LII-US were diagnosed with non-critical CHD or cardiac issues postnatally (negative predictive value = 94.7%). F-echo correctly diagnosed two of the six missed LII-US CHD. CONCLUSION: Critical CHD was not missed with a normal LII-US in this at-risk population. F-echo also missed the majority of CHD when a LII-US was read as normal. The cost/benefit of screening F-echo in fetuses with siblings with CHD should be evaluated if a normal LII-US has been performed. Larger studies are needed to determine if these findings remain consistent.