Non-invasive Continuous Cardiac Output Monitoring in Preterm Infants Study

This is a 3-year prospective observational study. Principal research question: Is non-invasive continuous cardiac output (CO) measurement a validated tool of comprehensive cardiovascular assessment in neonatal intensive care (NICU)? Secondary research questions: 1. Can robust normal ranges of CO be constructed for neonates undergoing cardiovascular measurement? 2. How do neonatal interventions (fluid boluses, ventilation and inotropes) affect CO? 3. Does the Non-invasive continuous cardiac output monitoring in children with foetal growth restriction (FGR) differ from normative CO data as above (1)? A prospective study of stable newborn babies in the postnatal ward and sick term and preterm infants in the NICU in 36 months.