Impact of foetal growth restriction and being born small for gestational age on newborn echo- and electrocardiographic measurements-a Copenhagen baby heart study

AIMS: Foetal growth restriction (FGR) and being born small for gestational age (SGA) have been linked to later cardiovascular disease. We examined the impact of FGR and SGA on neonatal echo- and electrocardiographic measurements in the Copenhagen Baby Heart Study.

METHODS AND RESULTS: The study included 26 175 newborns. Infants with FGR (n = 1020) and SGA (n = 2328) were compared to infants born appropriate for gestational age using linear regression with adjustment for body size, age at examination, sex, and gestational age at birth. FGR and SGA were associated with reduced left ventricular (LV) internal diameters in end-systole [adjusted mean difference (aMD) -0.09 mm, 95% confidence interval (CI) -0.18,0.01, and -0.12 mm, 95% CI -0.19, -0.06, respectively] and end-diastole (aMD -0.13 mm, 95% CI -0.24, -0.02, and -0.15 mm, 95% CI -0.22, -0.07, respectively). Exposed newborns also had thinner LV walls [interventricular septum, end-diastole: FGR -0.07 mm (95% CI: -0.11, -0.03), SGA -0.03 mm (95% CI -0.06, -0.01); LV posterior wall, end-diastole: FGR -0.05 mm (95% CI -0.09, -0.01), SGA -0.04 mm (95% CI -0.07, -0.01)]. Both groups exhibited changes in trans-mitral flow. FGR was associated with reduced right ventricular function (TAPSE aMD -0.20, 95% CI -0.31, -0.09), whereas SGA was associated with reduced LV end-diastolic (aMD -0.16, 95% CI -0.28, -0.04) and end-systolic volumes (aMD -0.08, 95% CI -0.13, -0.02) and alterations in electrocardiogram precordial leads. Both groups demonstrated reduced uncorrected QT intervals.

CONCLUSION: Newborns with FGR or SGA exhibited noteworthy cardiac changes, even after adjustment for body size. Follow-up studies are needed to determine the clinical significance of these findings for the later cardiovascular health.

KEY QUESTION: Is inadequate foetal growth associated with subclinical changes to the infant heart that can be observed in the newborn using echo- and electrocardiography?

KEY FINDING: Foetal growth restriction and being born small for gestational age were associated with reductions in left ventricular thickness and diameter, changes in diastolic function, and alterations in electrocardiographic parameters. Growth-restricted newborns also had altered right ventricular function.

TAKE-HOME MESSAGE: Foetal growth restriction and being born small for gestational age are associated with alterations in cardiac structure and function, even after adjustment for body size and age. Follow-up examinations of these children should be considered.