A quarter of very low birthweight babies needing assisted ventilation may develop chronic lung disease, requiring prolonged oxygen therapy in hospital, or even at home. Poor growth and lung function, and adverse developmental outcomes are common. In 1986, Action Research funded an international trial showing that babies treated with corticosteroids came off ventilators earlier. With short term health benefits, steroids became widely used. When any new treatment enters use (particularly in vulnerable preterm babies) it is essential to do long-term follow-up to be sure there are no unexpected adverse outcomes. So children are now being traced at age 11-14 for a full assessment of their lung function, growth and intellectual outcome.