a1 Department of Obstetrics and Gynaecology, Prince of Wales Hospital, Shatin, Hong Kong, China.
Corticosteroid treatment before preterm delivery was shown to be effective in reducing neonatal respiratory distress syndrome (RDS) more than three decades ago. The beneficial effect of steroids was further confirmed by Roberts and Dalziel's meta-analysis of 21 randomised controlled studies (RCT), which was published as a Cochrane Review in 2006. The authors concluded that the administration of a single course of steroids improved neonatal outcome, reducing RDS by 60%, periventricular haemorrhage (PVH) and necrotizing enterocolitis (NEC) by half, and neonatal death (NND) by 70%. However, these beneficial effects do not last for more than 7 days. Furthermore, steroids take at least 24 hours to be fully effective. Hence, it was advocated in the 1990's that regular weekly booster courses be given in order to maintain the therapeutic effects in high risk cases, as the timing of preterm birth cannot be readily predicted.
c1 Dr. TY Leung, Department of Obstetrics and Gynaecology, Prince of Wales Hospital, Shatin, Hong Kong, China SAR