Comparison between two doses of betamethasone administration with 12 hours vs. 24 hours intervals on prevention of respiratory distress syndrome: a randomised trial.

The purpose of the present study was to compare the effect of a two-dose administration of betamethasone with 12 hours interval vs. 24 hours interval on neonatal respiratory distress syndrome (RDS). The study was performed as a randomised clinical trial on 201 pregnant women with a gestational age of 26-34 weeks. In one group 12 mg of betamethasone every 12 hours for two doses and in the other group 12 mg of betamethasone every 24 hours for two doses were prescribed intramuscularly. There were no significant differences between the two groups according to maternal age, parity, gravidity, BMI, neonatal sex, need to surfactant, NICU admission, NICU stay, neonatal death, neonatal sepsis and Apgar score at minutes 1 and 5, but the gestational age at the beginning of the study and delivery receiving complete course of betamethasone and neonatal weight were lower in 24 hours group. RDS, necrotising enterocolitis, intra-ventricular haemorrhage and chorioamnionitis were more in the 24 hours' group. Multiple regression analysis showed that RDS and IVH (p = .022, RR = 0.07, CI95% 0.006-0.96 and p = .013; RR = 0.9, CI95% 0.1-0.89, respectively) were more in the 24 hours group and neonatal death (p = .034, RR = 4.7, CI95% 1.07-16.2) and NEC (p = 0.038, RR = 2.5, CI95% 1.7-3.7), were more in the 12 hours group. In conclusion, it seems that 12 hours interval betamethasone therapy may be considered as an alternative treatment in the case of preterm labour for acceleration of lung maturity; however, it is suggested that more studies should be performed on this issue and various morbidities. IMPACT STATEMENT What is already known on this subject: Administration of a single course of corticosteroids in all women with a gestational age of 24-34 weeks of pregnancy who are at risk for preterm labour and delivery has been recommended. The accepted regimen by National Institutes of Health (NIH) is an injection of betamethasone for two doses with 24 hours interval. What do the results of this study add: Twelve hours interval betamethasone therapy may be considered as an alternative treatment in the cases of preterm labour for acceleration of lung maturity. What are the implications of these findings for clinical practice and/or further research: Prescription of two doses (complete regimen) is more important than the interval between two doses for obtaining the maximum effect in a preterm birth.