Neonatal cardiac dysfunction in intrauterine growth restriction.

Background: The early postnatal cardiovascular consequences of intrauterine growth restriction (IUGR) have not been completely elucidated. This study aimed to evaluate the effect of IUGR on neonatal myocardial function and cardiovascular adaptation to extrauterine life.

Methods: Conventional and tissue Doppler echocardiographic parameters were compared on the second and fifth postnatal day between 30 IUGR and 30 appropriate-for-gestational age (AGA) neonates.

Results: IUGR neonates presented relative interventricular septum (IVS) hypertrophy (IVS to left ventricular (LV) posterior wall diastolic ratio: median IUGR-AGA difference of 0.05 (interquartile range: 0.04-0.06); P = 0.020), relative LV dilatation (wall thickness to end-diastolic LV dimension difference of 0.12 (0.06-0.16); P = 0.012), and increased left myocardial performance index (MPI difference of 0.19 (0.05-0.28); P = 0.012). Repeated measurements ANOVA revealed a different pattern of change in LV stroke volume (LVSV; P < 0.001), LV cardiac output (LVCO; P < 0.001), MPI (P < 0.001), and heart rate (HR; P = 0.025) between AGA and IUGR infants. From the second to the fifth postnatal day, AGA neonates presented a decrease in MPI and HR with an increase in LVSV and LVCO. IUGR neonates failed to achieve similar changes in MPI, HR, and LVSV, whereas their LVCO decreased.

Conclusion: IUGR neonates present changes in cardiac morphology and subclinical myocardial dysfunction, which may result in an altered pattern of cardiovascular adaptation to extrauterine life.