Mom’s Inflammation Linked to Autism

Autism diagnosis was more likely when mom had signs of inflammation in early pregnancy

(RxWiki News) Past research has shown that autism risk was higher when mothers were sick during pregnancy. New research sheds some light on how illness might be affecting autism risk.

In a recent study, researchers were interested in a blood protein that signals inflammation in pregnant mothers.

Pregnant women who had higher levels of the protein in their blood were about 12 percent more likely to have a child that was later diagnosed with autism.

The authors concluded that inflammation during early pregnancy was linked to a small increase in risk for autism.

"Ask your OB/GYN about any health concerns."

The researchers, led by Alan S. Brown, MD, MPH, of Columbia University, looked for a link between mothers' inflammation and autism using medical records from Finland.

Finland’s medical system has integrated medical records for 1.2 million children. Researchers were able to put together each child’s mental health records with the mother’s medical records from pregnancy.

As part of medical care, pregnant women in the study had a blood test during the first three to five months of their pregnancy. From this blood test, researchers measured mothers' levels of C-reactive protein (CRP).

CRP is a marker of inflammation. Levels of the protein rise when a person has an infection but can also rise when a person has other conditions that cause inflammation.

So the researchers looked at 677 cases of autism and a matched set of typically developing children for whom they had a maternal blood sample on record.

The researchers wanted to see if CRP levels in mothers were related to autism risk in children.

Results showed about a 12 percent increase in the risk of autism as CRP levels increased in the mothers' blood.

The mothers were then grouped into five categories from low to high, based on the level of CRP in their blood.

The researchers compared the high CRP group to the low CRP group and found that women in the high CRP group had about a 40 percent greater chance of having a child develop autism compared to the women in the low CRP group.

The authors concluded that inflammation experienced by the mother during early phases of pregnancy led to a small increased risk of autism in child.

In a recent press release, Dr. Brown said that it is important to view these results carefully. The number of women who have inflammation during pregnancy is much higher than the number of kids who develop autism.

The study was limited by the fact that the median age of the children was 4 years. Autism diagnosis can take place at an older age for some kids, especially those with milder symptoms. So, the study may be over- or underestimating the amount of risk.

This study was published in January in Molecular Psychiatry.  The study was funded by grants from the National Institute of Environmental Health Sciences, the National Institute of Mental Health, Autism Speaks and the State Research Institute. The authors reported no conflicts of interest.

Review Date: 
February 20, 2013