Objective: To evaluate whether magnesium sulphate (MgSO(4)) given to women at risk of very-preterm birth would be neuroprotective in preterm newborns.
Patients and methods: In 18 French centres, women with fetuses of gestational age less than 33 weeks whose birth was expected within 24 hours were randomised from 1993 to 2003 with follow-up of infants until two years of age after discharge. They received a single injection of 0.1 mg/l de MgSO(4) (4g) or isotonic 0.9% saline over 30 minutes. This study is registered as an International Standard Randomised Controlled Trial, number 00120588. Analyses were based on intention to treat.
Results: Data from 688 infants were analysed of which 606 were followed up and 10 were lost to follow-up. Comparing infants who received MgSO(4) or placebo, respectively, has shown a decrease of all primary endpoints (total mortality, severe white matter injury and their combined outcome) and of all secondary endpoints (motor dysfunction, cerebral palsy, cognitive dysfunction and their combined outcomes at two years of age) in the MgSO(4) group. The decrease was nearly significant or significant for gross motor dysfunction (OR: 0.65 [0.41-1.02]) and combined criteria: death and cerebral palsy (OR: 0.65 [0.42-1.03]); death and gross motor dysfunction (OR: 0.62 [0.41-0.93]); death, cerebral palsy and cognitive dysfunction (OR: 0.68 [0.47-1.00]). No major maternal adverse effects were observed in the MgSO(4) group.
Discussion and conclusion: Given its beneficial effects and safety, the use of prenatal low-dose MgSO(4) for preventing neurodisabilities of very-preterm infants should be discussed either as a stand-alone treatment or as part of a combination treatment, at least in the context of clinical trials.