The role of magnesium sulfate in the prevention of cerebral palsy.

Magnesium sulfate (MgSO4) has been widely used in the perinatal arena for many decades. It has been used for tocolysis in the U.S. for more than 60 years. Estimations of MgSO4 use for preterm labor (less than 34 weeks of gestation) run as high as 80 percent. Magnesium sulfate is a smooth, skeletal, and cardiac muscle depressant. It is used for preterm labor because of its potential to decrease muscle contractility by interfering with calcium uptake in the cells. Thousands of moms and babies have been exposed to this medication even though tocolysis remains an off-label use, the exact mechanism of action is not completely understood, and there are studies that show that it is ineffective for this indication, and no evidence that it improves perinatal outcomes.1-3 Additionally, it is a high alert medication because of its narrow therapeutic window and the risk of causing an immediate life-threatening condition (acute respiratory failure) if an error in administration occurs.4.