NIH Report: Prenatal Inflammation Linked to Autism Risk
Increased risk found in children of mothers with elevated C-reactive protein (Jan. 24)
Maternal inflammation during early pregnancy may be related to an increased risk of autism in children, according to a new study supported by the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health (NIH). The researchers found an increased risk of autism in children of mothers with elevated serum levels of C-reactive protein (CRP), a well-established marker of systemic inflammation.
The risk of autism among children in the study was increased by 43% among mothers with CRP levels in the top 20th percentile, and by 80% for maternal CRP in the top 10th percentile.
The new findings — published in Molecular Psychiatry — add to mounting evidence that an overactive immune response can alter the development of the central nervous system in the fetus.
“Elevated CRP is a signal that the body is undergoing a response to inflammation from, for example, a viral or bacterial infection,” said lead investigator Alan Brown, MD.
Brown cautioned that the results should be viewed in perspective since the prevalence of inflammation during pregnancy is substantially higher than the prevalence of autism.
“The vast majority of mothers with increased CRP levels will not give birth to children with autism,” Brown said. “We don’t know enough yet to suggest routine testing of pregnant mothers for CRP for this reason alone; however, exercising precautionary measures to prevent infections during pregnancy may be of considerable value.”
The study involved data from the Finnish Maternity Cohort (FMC), which consists of 1.6 million serum specimens from approximately 810,000 women. From this large national sample, the researchers analyzed CRP in archived maternal serum corresponding to 677 childhood autism cases and to an equal number of matched controls.
The study’s findings are expected to stimulate further research on autism. According to the authors, additional studies may help define how infections, other inflammatory insults, and the body’s immune response interact with genes to elevate the risk for autism and other neurodevelopmental disorders.
Source: NIH; January 24, 2013.