Since the introduction of prenatal corticosteroids (CS) in the 1970's for women at risk of preterm delivery, the incidence and severity of RDS and neonatal mortality háve decreased. Although the CS are ušed for more than three decades to induce fetal lung maturity, there are some areas of problems associated with prenatal CS that remain to be answered. Evidence based knowledge suggests for that one course of prenatal CS is sufficient to enhance fetal lung maturity. The repeated fetal exposure to CS ("rescue") is considered hazardous námely for the developing immature brain. Therefore the "rescue" CS treatment is not recommended as the routine proceduře. However, it seems that reduced dose of prenatal CS has comparable stimulatory effect to the fetal lung with the full dose but the suppression of the fetal growth, the injurious effect to the immature brain and to the hypothalamic-pituitary-adrenal function are reduced. The contemporary research activities are directed towards the role of exogenous CS in the programming of fetal and neonatal development during perinatal period and its association with the later health problems.

        Key words: prenatal corticosteroids, neonatal morbidity, neonatal mortality, fetal growth, lung maturity, brain development, corticosteroid side effects