Corticosteroids given to women in early labour help the babies' lungs to mature and so reduce the number of babies who die or suffer breathing problems at birth.
Babies born very early are at risk of breathing difficulties (respiratory distress syndrome) and other complications at birth. Some babies have developmental delay and some do not survive the initial complications. In animal studies, corticosteroids are shown to help the lungs to mature and so it was suggested these drugs may help babies in preterm labour too. This review of 21 trials shows that a single course of corticosteroid, given to the mother in preterm labour and before the baby is born, helps to develop the baby's lungs and reduces complications like respiratory distress syndrome. Furthermore, this treatment results in fewer babies dying and fewer common serious neurological and abdominal problems, e.g. cerebroventricular haemorrhage and necrotising enterocolitis, that affect babies born very early. There does not appear to be any negative effects of the corticosteroid on the mother. Long-term outcomes on both baby and mother are also good.