Researchers found that magnesium sulfate given to women who were at risk of delivering a premature baby reduced the risk of cerebral palsy by nearly half. In the United States every year about 8,000 babies and infants are diagnosed with cerebral palsy and premature birth is a major cause of this neurological disorder.

Study lead author Dr. Dwight J. Rouse, a professor of obstetrics and gynecology at the University of Alabama at Birmingham said, "If deemed to be at high or immediate risk of delivery prior to 32 weeks, women and their doctors should consider using magnesium sulfate to prevent their child from having cerebral palsy.

The 20 center study had the UNC Hospitals as a part of it to study the effect of Epsom salt and the findings are published in the New England Journal of Medicine. In those suffering from Cerebral Palsy the brain has difficulty in communicating with the muscles due to damage or dysfunction to the fetal brain. This results in abnormal body movement, lack of control and postures that result in limited activity. Premature birth is a major risk factor with one third of cerebral palsy cases being associated with this cause. When the magnesium sulfate is not administered before birth approximately 10 out of 100 premature babies would develop the disorder by the time they reach the age of 2 years.

Dr. John Thorp, obstetrician at UNC Hospitals and a co-author of the magnesium sulfate study, said, “In the group exposed to magnesium, that number was about 5 in 100. So it reduced the risk of Cerebral Palsy by half." He said the findings would be helpful in the fight to prevent cerebral palsy. “I think this is the most exciting thing that's happened in my 25 years as an obstetrician,” he added.

Earlier studies on magnesium sulfate had not shown any benefit in delaying early labor though it had proven to be effective for the treatment of maternal high blood pressure associated with pregnancy. Its effectiveness for reducing the risk of cerebral palsy had been studied but the results had been inconclusive.

In the current study undertaken on a larger scale by Rouse, no significant difference in the proportion of deaths between the magnesium sulfate group and the placebo group was seen. The study did point out that moderate or severe cerebral palsy was diagnosed in only 1.9 % of the people treated with magnesium sulfate as compared to the 3.5 % of the placebo group.

Though they are uncertain as to how the magnesium sulfate works, Rouse feels it may "stabilize the vessels in the vulnerable preterm brain," thereby protecting it against any damage from lack of oxygen as well as guard against injury caused by swelling and inflammation. "Our findings are applicable only to early preterm birth," Rouse added. "We define high risk as threatening delivery prior to 32 weeks."

Dr. William Zinser, a pediatric neurologist at Children's Medical Center, Dallas, and an associate professor of pediatric neurology at the University of Texas Southwestern Medical Center was not involved with the study though he reviewed it. He said, "It's too early to know if magnesium sulfate has an overall effect on the incidence rate of cerebral palsy. More research needs to be done, certainly."

Side effects of magnesium sulfate are said to be a warm feeling and a little nausea, it has been associated a marginal risk of infant death.