Morbidity of neonates born before 32 weeks remains significant. Cerebral palsy is found in up to 8 to 10% of survivors. Three randomized controlled trials evaluated the effectiveness of magnesium sulphate given to mothers with a risk of imminent very preterm delivery to prevent perinatal death or cerebral palsy in children. These studies suggest a reduction of the risk of cerebral palsy by magnesium sulphate from 6.5% to 4.8% (relative risk 0.71, 95% CI 0.55-0.91). These results remain controversial, but warrant information to the parents and the implementation of treatments protocols for selected cases.