Randomized controlled trial of magnesium sulfate infusion for severe birth asphyxia.

Objective: To determine whether postnatal MgSO(4) infusion (250 mg/kg per day) for 3 days is both safe and able to improve outcome in infants with severe birth asphyxia, as had been suggested by a small pilot study.

Methods: A multicenter randomized controlled trial was conducted. Entry criteria included 5-min Apgar score of seven or less and either failure to initiate spontaneous respiration at 10 min after birth because of asphyxia, or occurrence of clinically apparent seizures within 24 h after birth. Number of subjects was calculated to detect a 50% reduction in incidence of adverse outcomes.

Results: Distributions of perinatal factors, neonatal baseline characteristics and severity of hypoxic-ischemic encephalopathy were similar in treated and control groups. No significant differences were observed in duration of clinical seizures, or need for assisted ventilation. Survival with normal results of cranial computed tomography, electroencephalography and establishment of oral feeding by 14 days of age, was significantly more frequent in the treated group than in the control group (12/17 vs 5/16, P = 0.04). No significant differences in blood pressure, heart rate or respiratory rate were observed between groups.

Conclusion: Postnatal MgSO(4) infusion as above is safe and can improve short-term outcome in infants with severe birth asphyxia.