CORRECTED: Epsom salt can prevent cerebral palsy: U.S. study

Corrects number of women tested in 8th paragraph to 2,241 from 241

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - Giving a woman an infusion of Epsom salts when she goes into premature labor can help protect her baby from cerebral palsy, U.S. researchers reported on Thursday.

Magnesium sulfate, popularly known as Epsom salts, cut the rate of cerebral palsy in half, Dr. John Thorp, a professor of obstetrics at the University of North Carolina at Chapel Hill, and colleagues reported.

"We have a cheap, widely available treatment already in hand that cuts in half the risk of babies being born with an extremely disabling disorder," Thorp said in a statement.

"And virtually every delivery room in the United States is already stocked with magnesium sulfate solutions that are given to pregnant women during childbirth for other reasons."

Dr. Alan Fleischman, medical director of the birth defect charity March of Dimes, was more cautious. "I think it is an important study," he said in a telephone interview.

But he noted that more study was needed to understand how the treatment works, and said the children were not protected from more subtle brain damage that affected intellectual and cognitive function.

Thorp's team presented their findings to a meeting of the Society for Maternal-Fetal Medicine in Dallas.

They gave either magnesium sulfate or a placebo to 2,241 women going into early labor or with ruptured membranes. The women's pregnancies were at between 24 to 31 weeks -- a full-term pregnancy goes 40 weeks.

Babies born as prematurely as that can suffer brain damage and other problems including cerebral palsy, a range of conditions that affect control of movement and posture.

PROTECTING THE BRAIN

The magnesium did not prevent any deaths among the premature babies. But 4.2 percent of the babies born to women given magnesium developed cerebral palsy, versus 7.3 percent of those born to women who got the placebo.

The researchers followed the infants that were born for up to two years.

It is not clear how the magnesium works but it may stabilize the blood vessels, prevent the damage caused by having oxygen cut off and also help prevent immune system damage to the brain, Thorp's team said.

"Magnesium sulfate may impact on blood flow in the fetal brain and help to decrease damage in the brain," Fleischman said in a telephone interview.

One question he had was why magnesium sulfate could protect against cerebral palsy but not the other brain effects of being born prematurely.

Fleischman agreed there was little downside to using magnesium sulfate, if done properly. "Obstetricians are comfortable with it and they use it frequently," he said.

"It was first was used for pre-eclampsia, to prevent women from going into eclampsia, which is a seizure." It can also inhibit premature labor, he noted.

An earlier study in Australia, which included more than 3,000 women, had similar results. The March of Dimes estimates that 500,000 people have cerebral palsy in the United States.

(Editing by Michael Kahn and Alan Elsner)