<qa>  What is the sample size analysis based on?Sample size analysis is based on morbidity and mortality from the Finnish perinatal statistics National Research and Development Centre for Welfare and Health and from Vermont Oxford Network Database VON. We estimate that a second additional dose of betamethasone would increase the survival without RDS and severe ICH from 50 to 62.5. According to power analysis the sample size of 220 women would be required in each arm to reject the null hypothesis with and α of 0.05 and power of 80. 