A study conducted by U researchers could potentially change the way doctors treat mothers at risk of giving birth prematurely.
Magnesium sulfate, a chemical often found in bath salts and used by farmers to treat soil deficiencies, was found to significantly reduce the risk of cerebral palsy in premature babies when delivered intravenously to their mothers prior to birth.
Michael Varner, professor and vice chair for research in the department of obstetrics and gynecology at the U and a key researcher in the study, said magnesium sulfate has been used for more than 30 years to postpone premature labor. However, its effectiveness, he said, has been minimal at best.
In the mid-’90s a group of doctors and researchers stumbled across a link between magnesium and decreased cerebral palsy rates, spurring the decade-long study that included researchers from the U and 19 other institutions around the world.
The study was published today in the The New England Journal of Medicine.
“We still don’t have a good handle on what causes cerebral palsy in preterm babies,” Varner said. “And how magnesium fits in this whole equation, we don’t really know. But we have used it long enough to know that it’s safe. I’m sure that this will change some aspects of high-risk obstetrics and change habits and practices in delivery rooms.”
During the multi-institutional study cofounded by the National Institute of Neurological Disorders and Stroke, 2,241 women determined to be at risk for preterm birth8212;many of them from Utah8212;were randomly assigned to receive either a placebo or magnesium sulfate. Of the mothers who received magnesium, 4.2 percent of their children developed cerebral palsy, whereas 7.3 percent of premature babies whose mothers received a placebo developed the disease.
Cerebral palsy is the term given to a group of neurological disorders that limit control of movement, posture and activity. Although the cause is not well understood, cerebral palsy is attributed to brain injury or developmental abnormality during pregnancy, birth or in early childhood.
“The rate of cerebral palsy incidence certainly isn’t going down,” Varner said. “There are an average of two pre-term children born each week with cerebral palsy in Utah. This is a significant problem.”
In May 2004, Christi Johnson was rushed to the Utah Valley Regional Medical Center when she began experiencing complications with her pregnancy. She was only seven months pregnant, but when her water broke, she knew her baby was coming.
A nurse working at the hospital had been working with U researchers and suggested that Johnson receive two treatments of magnesium sulfate IV immediately.
“I didn’t hesitate for a second,” Johnson, 27, said. “I had two treatments and my son was born the next day. He never had any of the complications or surgeries that so many premature babies undergo…I can’t really say if it was the magnesium, but I’m glad I opted for the treatment.”
Varner said medical authorities such as the Maternal Fetal Medicine Network will review the new study before making wider recommendations to doctors around the globe.
According to a recent study by the Washington University School of Medicine, about 12.5 percent of babies in the United States are born prematurely. For reasons that doctors do not fully understand, the rate of premature birth has increased by more than 30 percent since 1981.
With an estimated 200,000 American children affected, it is a leading cause of childhood disability. Premature babies are at increased risk for several health complications including mental retardation, vision and hearing loss, cerebral palsy, lung and gastrointestinal problems and even death, according to the study.
“I really do think our findings are going to change things,” Varner said. “I’m very grateful to all of the women who took part in the study and to all the researchers and University of Utah faculty that made it possible.”