Descriptive analysis of different phenotypes of cardiac remodeling in fetal growth restriction.

OBJECTIVE: To identify different cardiac phenotypes among cases of fetal growth restriction (FGR).

METHODS: Echocardiography was performed in 126 cases with FGR (birth weight < 10th centile) and 64 appropriate-for-gestational-age (AGA) fetuses. Principal component and cluster analyses were performed to identify different cardiac phenotypes among FGR cases.

RESULTS: Three different cardiac phenotypes were identified among the FGR group: globular in 54% of cases, elongated in 29% of cases and hypertrophic in 17% of cases. Those with a globular heart had the lowest median left-ventricular sphericity index (controls, 1.78 (interquartile range (IQR), 1.62-1.97); FGR elongated, 1.92 (IQR, 1.78-2.09); FGR globular, 1.44 (IQR, 1.36-1.52); FGR hypertrophic, 1.65 (IQR, 1.42-1.77); P = 0.001). FGR cases with an elongated left ventricle had nearly normal cardiac dimensions. FGR cases with a hypertrophic phenotype had the highest median left-ventricular wall thickness (controls, 1.22 (IQR, 1.10-1.67) mm/kg; FGR elongated, 1.52 (IQR, 1.28-1.86) mm/kg; FGR globular, 1.65 (IQR, 1.39-1.99) mm/kg; FGR hypertrophic, 3.68 (IQR, 3.45-4.71) mm/kg; P = 0.001) and cardiac dimensions. Globular and elongated phenotypes showed a fetoplacental profile of late-onset FGR, while the hypertrophic phenotype showed signs of early-onset FGR. The hypertrophic group also had the poorest perinatal results, having the lowest birth-weight centile, gestational age at delivery and Apgar score and the highest postnatal blood pressure and aorta intima-media thickness.

CONCLUSIONS: FGR induces at least three different cardiac phenotypes, with early-onset FGR cases being associated with a hypertrophic response and worse perinatal outcomes. This cardiac phenotypic classification may improve identification of FGR cases with the highest perinatal and long-term cardiovascular risks. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.