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Centre for Evidence-
Based Medicine

Cerebral Palsy: Associated with maternal infection

Clinical Bottom Line

There is a strong association between maternal infection and congenital CP. This provides an impetus for future research aimed at preventing and treating intrauterine inflammation.


Grether JK., Nelson KB. Maternal infection and cerebral palsy in infants of normal birth weight. JAMA 1997; 278:207-11.

Clinical Question

In children who were born full-term with normal birth weight, is maternal infection a possible cause of congenital cerebral palsy?

Search Terms

You perform a PubMed search using the MeSH terms "cerebral palsy" and "maternal infection". Of the 6 articles identified, only one deals with infants of normal birth weight. You review the abstract in PubMed and decide to copy the entire article JAMA 1997; 278:207-11.

The Study

  • Case-control Study.
  • The Study Patients: Cases were all singleton children born in 1983 through 1985 to residents of 4 San Francisco Bay-area counties and included all children who met the following criteria: weighed 2500 grams or more at birth, survived to age 3 years, were residents of California to that age, and had moderate or severe congenital CP. Control children were randomly selected from singleton children who met all the case criteria except for having CP.
  • Exposure of Interest: Maternal infection.
  • The Outcome: Congenital cerebral palsy.
  • Subjects defined and similar in other important ways, exposures and outcomes objective or measured blind.

The Evidence

Adverse Outcome Totals
Present (case) Absent (control)
Exposed to the potential harm Yes (Cohort)






a + b

No (Cohort)






c + d


a + c


b + d


a + b + c + d


Odds ratio: 9.27, 95% CI 8.43 to 10.10
X² :27.01

Particular to my patient:

PEER: 0.08933
NNH: 3


It is uncertain why maternal infection is associated with CP. However, it is plausible that cytokines and other mediators may cross the placenta and the blood-brain barrier of the fetus, and disturb neuronal and glial development.

Appraised By

Barbara Schmidt, MD, MSc, FRCP(C), and Bo Zhang, MPH
HSC 3N11E, Department of Pediatrics and Clinical Epidemiology & Biostatistics
McMaster University
1200 Main Street West, Hamilton, Ontario, Canada L8N 3Z5

Fax: (905) 521-5007
Friday, February 25, 1999
Email: schmidt@fhs.mcmaster.ca, zhangbo@fhs.mcmaster.ca

Expiry Date

Kill or Update By: December 31, 2000