Cardiovascular Adaptation in Fetal Growth Restriction: A Longitudinal Study From Fetuses at Term to the First Year of Life

Objective: To investigate longitudinal trends in fetal and offspring cardiovascular adaptation in fetal growth restriction (FGR). Design: Prospective longitudinal study. Setting: Fetal Medicine Unit. Sample: Thirty- five FGR pregnancies and 37 healthy controls assessed as term fetuses (mean age 37 +/- 1 weeks) and again in infancy (mean age 8 +/- 2 months). Methods: Conventional echocardiographic techniques, tissue Doppler imaging and speckle tracking echocardiography. Main Outcome Measures: Left ventricular (LV) and right ventricular (RV) geometry and function. Echocardiographic parameters were normalised by ventricular size adjusting for differences in body weight between groups. Results: Compared to healthy controls, late FGR fetuses showed significant alterations in cardiac geometry with more globular LV chamber (LV sphericity index, 0.56 vs. 0.52), increase in biventricular global longitudinal systolic contractility (MAPSE, 0.29 vs. 0.25 mm; TAPSE, 0.42 vs. 0.37 mm) and elevated cardiac output (combined CO: 592 vs. 497 mL/min/kg, p < 0.01 for all). Indices of LV diastolic function in FGR fetuses were significantly impaired with myocardial diastolic velocities (LV A', 0.30 vs. 0.26 cm/s; IVS E', 0.19 vs. 0.16 cm/s) and LV torsion (1.2 vs. 3.5 deg./cm, p < 0.01 for all). At postnatal assessment, FGR offspring revealed persistently increased SAPSE (0.27 vs. 0.24 mm), LV longitudinal strain (-19.0 - 19.0 vs. - 16.0%), reduced LV torsion (1.6 vs. 2.1 deg./cm) and elevated CO (791 vs. 574 mL/min/kg, p < 0.01 for all). Conclusions: Perinatal cardiac remodelling and myocardial dysfunction in late FGR fetuses is most likely due to chronic placental hypoxaemia. Persistent changes in cardiac geometry and function in FGR offspring may reflect fetal cardiovascular maladaptation that could predispose to long- term cardiovascular complications in later life.