This study aims to determine the effectiveness of antenatal corticosteroid therapy in late preterm babies. The investigators hypothesis is corticoid accelerates fetal lung maturation even after 34 weeks and reduces risk of respiratory distress syndrome and other neonatal morbidities.

Late preterm babies have important morbidity when compared with term babies, with oxygen requirement and more days of hospitalization. If antenatal corticosteroid therapy is necessary for fetal lung maturation after 34 weeks, it remains to be established. The systematic review with metanalysis in Cochrane Library includes a small number of late preterm babies and no conclusion about effectiveness of corticoid therapy in this setting could be drawn. Our hypothesis is that antenatal corticosteroid therapy is effective to prevent respiratory disease and morbidity in late preterm babies and this study will be carried out to evaluate this question.

Inclusion Criteria:

• Pregnancy between 34 and 36 weeks
• Confirmed gestational age (LMP, USG)
• Alive fetus
• Imminent risk of preterm delivery

Exclusion Criteria:

• Multiple pregnancy
• Major fetal malformations
• Comproved fetal lung maturity
• Maternal or fetal indication for immediate interruption of pregnancy
• Maternal hemorrhagic syndromes (placenta previa, abruptio placenta)
• Chorioamnionitis
• Chronic use of corticosteroids
• Previous use of corticosteroids for fetal lung maturation in the current pregnancy