Examining the Effects of Prenatal Magnesium Sulfate Exposure on the
Risk for Cerebral Palsy in Low Birthweight Children
Background: In 1995, researchers with the California
Birth Defects Monitoring Program, Cerebral Palsy Project, reported about
an 80% lower prevalence of cerebral palsy among very low birthweight
children (<1500 gms) whose mothers had been treated with magnesium
sulfate during pregnancy, either for preeclampsia or preterm labor, in
comparison with very low birthweight children whose mothers were not
treated with the drug.1
Subsequently, researchers in the Developmental Disabilities Branch also
reported an apparent protective effect of prenatal magnesium sulfate
exposure on the risk for cerebral palsy or mental retardation among very
low birthweight children, based on information obtained through the Metropolitan
Atlanta Developmental Disabilities Surveillance Program (MADDSP) and
the Georgia Very Low Birthweight Study.2These
preliminary studies, based on small numbers of children, prompted DDB
researchers to conduct the Infant Development Study (IDS) involving a much
larger group of children.
Description: The Infant Development Study (IDS) is a
case-control study to investigate the apparent protective effect of
prenatal magnesium sulfate exposure on the risk for cerebral palsy among
low birthweight children. Over 200 children who have cerebral palsy, who
were born in the 5-county metropolitan Atlanta area from 1981 through
1989, and who weighed less than 1750 grams at birth, were selected as age
subjects for the IDS from MADDSP 1991-92 surveillance records. A sample of
over 300 control children born during the same time interval were randomly
selected from vital record files of the Georgia Department of Human
Resources, on the basis of birth weight and plurality. For each child
included in the study, information on selected maternal and infant
characteristics was abstracted from the hospital admission and labor and
delivery records of the mother and the newborn records of the child.
This information included: maternal treatment with magnesium sulfate and
selected other drugs (other tocolytics, steroids and antihypertension
medications) during pregnancy; the presence of preeclampsia, hypertension,
proteinuria and other maternal medical conditions during pregnancy;
characteristics of labor and delivery; and characteristics and medical
course of the newborn. The large numbers of affected children included in
the IDS will permit researchers to carefully examine many of the factors
that might explain why maternal magnesium sulfate treatment during
pregnancy appears to protect very low birthweight infants from developing
cerebral palsy.
References:
1. Nelson KB, Grether JK. Can magnesium sulfate reduce
the risk of cerebral palsy in very low birthweight infants? Pediatrics
1995; 95:263-269. (Abstract)
2. Schendel, DE, CJ Berg, M
Yeargin-Allsopp, CA Boyle, P Decouflé. Prenatal magnesium sulfate
exposure and the risk for cerebral palsy or mental retardation in very low
birthweight children aged 3 to 5 years. JAMA 1996; 276:1805-1810.
(Abstract)
Date: October 29, 2005
Content source: National Center on Birth Defects and Developmental
Disabilities
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