Giving pregnant women magnesium sulfate within 24 hours of delivering a very preterm baby reduced the risk of cerebral palsy but showed no additional effect in the children’s outcomes 6-11 years later, found a new study.
“There were no substantial differences between groups on any of the cognitive, academic, attention, executive function, or behavioral outcomes, and none of the differences reached statistical significance,” Dr. Lex W. Doyle, professor of neonatal pediatrics at the University of Melbourne and head of clinical research development at the Royal Women’s Hospital, also in Melbourne, and his associates reported online.
“There were no statistically significant differences between groups on any of the growth, functional, or other neurosensory outcomes,” they wrote. (JAMA 2014;312:1105-13 [doi:10.1001/jama.2014.11189]). They also noted, however, that “a mortality advantage could not be excluded.”
From 1996 to 2000, a total of 1,255 pregnant women who were expected to give birth within 24 hours, at less than 30 weeks’ gestation, were randomized to receive either 4 g of intravenous magnesium sulfite with 1 g/hour thereafter or saline placebo.
During 2005-2011, the researchers followed 334 children whose mothers received magnesium and 335 whose mothers received placebo.
Using data from parent and teacher questionnaires and various assessments, Dr. Doyle’s group evaluated the children’s cerebral palsy, motor function, IQ, academic skills, attention, executive function, behavior, growth, and functional and neurosensory outcomes at ages 6-11 years old, corrected for prematurity.
Minor differences in cerebral palsy or its severity and motor function between the two groups did not reach statistical significance. In both groups, 27% of children showed definite motor dysfunction. On all other assessments, the children in both groups had similar results and no differences reached statistical significance.
“The absence of benefit associated with antenatal magnesium sulfate into school age from the current trial does not negate the proven value of magnesium sulfate in reducing cerebral palsy, based on the collective evidence from all of the RCTs [randomized, clinical trials],” the authors noted.
The study was supported by the Australian National Health and Medical Research Council and the Victorian Government’s Operational Infrastructure Support Program. The authors reported no disclosures.