[Pre- and post-natal corticosteroids: side effects].

It is well known that prenatal steroid therapy (ST) reduces the mortality rate and the incidence of respiratory distress syndrome and intraventricular haemorrhage in premature infants. The benefits and safety of repeated courses of antenatal ST are doubtful due to possible side effects in the mother and baby. Experimental studies in animals have shown that multiple courses of antenatal ST have deleterious effects on lung growth and organisation, brain myelination, hypothalamic-pituitary-adrenal function and retina development. In humans, exposure to multiple courses of antenatal ST is associated with small head circumference at birth and increased incidence of maternal endometritis and early-onset neonatal sepsis. When administered soon after birth, ST may enable a reduction in ventilator settings and facilitate weaning from mechanical ventilation, but although associated with rapid improvement in lung function, it does not modify mortality or long-term outcome and has many acute side effects. Deleterious effects on lung maturation and neuro-developmental outcome, including cerebral palsy, have also been reported. The paucity of follow-up data is a major problem, and further prospective trials are needed.