Review and meta-analysis: Benefits and risks of multiple courses of antenatal corticosteroids

Abstract
Background. Preterm birth causes infant morbidity and mortality. A single course of antenatal corticosteroids (ACS) should be considered routine for preterm delivery. Benefits of therapy before 34 weeks' gestation have been established for infants born between 24 h and 7 days after treatment. It is still unclear whether multiple courses (MC) of ACS should be performed in women at risk of preterm delivery 7 days or more after initial treatment. Objectives. To determine the risks and benefits of MC of ACS. Methods. Search and selection for human randomized controlled trials were conducted in PubMed and The Cochrane Central Register of Controlled Trials. Statistical analysis was performed using the Review Manager 4.3 software. Main results. MC of ACS were associated with a statistically decrease in the occurrence of respiratory distress syndrome, patent ductus arteriosus, use of surfactant, ventilation support, and any maternal side effects. This treatment was also associated with a significant reduction in birth weight and head circumference. Conclusions. MC of ACS in women at risk of preterm birth do not offer significant benefits concerning the composite neonatal morbidity. Data on long-term safety are still insufficient. Further evaluations, most by follow-up studies, are required to study the long-term effects.