Premature babies have a high risk of lung disease and breathing difficulties (respiratory distress syndrome). A single course of corticosteroids before premature delivery is the most effective known strategy of reducing respiratory illness in these babies. Some previous studies suggest that repeating the dose of prenatal corticosteroids may be beneficial for babies but others have reported adverse side effects, including growth problems, infection after birth, and abnormal development in childhood.
To investigate the effectiveness and safety of repeat corticosteroids, Caroline Crowther (Women's and Children's Hospital, North Adelaide, SA, Australia) and colleagues recruited 982 pregnant women at risk of preterm birth into their trial. The women were less than 32 weeks pregnant and had received a single dose of corticosteroids 7 or more days before. The team randomly assigned participants to receive a repeat injection of corticosteroids or a placebo every week until 32 weeks of pregnancy, if they remained at risk of a preterm birth. The researchers followed-up the babies until discharge from hospital and found that fewer babies had respiratory distress syndrome (186 vs 239 / 33% vs 41%) or severe lung disease (65 vs 114 / 12% vs 20%) in the repeat corticosteroids group than in the placebo group. Babies exposed to repeat corticosteroids also needed less oxygen therapy and help breathing. The investigators did not find any difference in the weight, length, and head circumference of the babies in the two treatment groups.
Professor Crowther states: "These short-term benefits for the babies in our study support the use of repeat doses of corticosteroids in women who remain at risk of very preterm birth 7 or more days after an initial course." The authors say longer-follow up is needed to see if repeat prenatal corticosteriods have any long-term effects.
See also accompanying Comment.
Contact: Professor Caroline A Crowther, Department of Obstetrics & Gynaecology, University of Adelaide, Women's and Children's Hospital, 72 King William Road, North Adelaide, SA 5006, Australia. T) +61 8 8161 7000 caroline.crowther@adelaide.edu.au
Journal
The Lancet