Assessment of Diastolic Function During the Transitional Period and Infancy Using Serial Echocardiography

The goal of this single-centre longitudinal observational study is to create reference values for diastolic function parameters in neonates born at 35 weeks' gestation or above, and to assess the influence of pre-defined antenatal, intrapartum, maternal, and neonatal factors on cardiac function. The main question it aims to answer are: * What are the normal reference ranges for parameters of diastolic cardiac function in neonates? * How are these influenced by maternal, intrapartum and neonatal factors? * Do the diastolic changes noted during the first two days of life persist into infancy? Participants will have four echocardiographic assessments in total: * Two during the first 48 hours of life (prior to discharge home) * Two during infancy (as an outpatient)