Cerebral palsy (CP) is the most prevalent chronic childhood motor disability with an estimated lifetime cost of nearly $1 million per individual. There is evidence that magnesium sulfate (MgSO4) can reduce the incidence of CP for very early preterm infants. Many thousands of pregnant women and their fetuses are exposed to MgSO4 every year in the United States for a variety of indications, and most obstetricians are comfortable with its use. Yet, there is still some controversy over whether magnesium sulfate is truly protective against CP. In three articles published in the June 2009 issue of theAmerican Journal of Obstetrics & Gynecology, the authors shed some light on the debate.