A quarterly publication of the Autism Research Institute
Fall, 2019 | Number 4, Volume 33
Mothers who are anemic during early pregnancy are at increased odds of having a child with an autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), or intellectual disability, according to a new study conducted by researchers in Sweden and the United States.
Aline Marileen Wiegersma and colleagues analyzed data from nearly 300,000 mothers and more than half a million children born in Sweden between 1987 and 2010. The researchers found that, compared to children born to non-anemic mothers or mothers who developed anemia in late pregnancy, children born to mothers with anemia diagnosed before the thirty-first week of pregnancy had a slightly elevated risk of ASD or ADHD and a significantly higher risk of intellectual disability. When comparing siblings born to the same mother, the researchers found that children exposed to early maternal anemia were at higher risk of ASD and intellectual disability compared to unexposed siblings. However, anemia diagnosed after the thirtieth week of pregnancy was not associated with a higher risk for any of the conditions.
“A diagnosis of anemia earlier in pregnancy might represent a more severe and long-lasting nutrition deficiency for the fetus,” study coauthor Renee Gardner comments. “Different parts of the brain and nervous system develop at different times during pregnancy, so an earlier exposure to anemia might affect the brain differently compared to a later exposure.”
The researchers say that while they could not ascertain the specific causes for the mothers’ anemia, iron deficiency is the most common cause of anemia. They note that an estimated 15 to 20 percent of pregnant women suffer from iron deficiency anemia, and they encourage doctors to screen for this problem in early pregnancy.
Editor’s note: Anemia can also stem from folate or vitamin B12 deficiencies, both of which have been implicated as possible contributors to autism.
“Association of prenatal maternal anemia with neurodevelopmental disorders,” Aline Marileen Wiegersma, Christina Dalman, Brian K. Lee, Håkan Karlsson, and Renee M. Gardner, JAMA Psychiatry, September 18, 2019 (free online). Address: Renee M. Gardner, Department of Public Health Sciences, Karolinska Institutet, Stockholm SE-171 77, Sweden, [email protected].
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“Early maternal anemia tied to intellectual disability, ADHD and autism,” news release, Karolinska Institutet, August 18, 2019.
