Secondary outcomes: Incidence of death, major neonatal morbidities (BPD, intraventricular haemorrhage, periventricular leukomalacia, retinopathy of prematurity, necrotising enterocolitis), pneumothorax and patent ductus arteriosus; need for intubation and surfactant therapy; durations of mechanical respiratory support, intubation, CPAP, intubation and CPAP, high flow nasal cannula (HFNC), oxygen therapy, intensive care stay and hospitalisation; hospitalisation cost; applicability and safety of the MIST procedure; and outcome at 2 years.