Women who suffer from anemia early in pregnancy are at risk for having a child with autism, attention-deficit/hyperactivity disorder (ADHD) and intellectual disabilities, a study by Swedish researchers suggests.
The study couldn't prove cause and effect, but "a diagnosis of anemia earlier in pregnancy might represent a more severe and long-lasting nutrition deficiency for the fetus," theorized lead researcher Renee Gardner. She's project coordinator at the department of public health sciences at the Karolinska Institute in Stockholm.
"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," she explained in a university news release.
About 15% to 20% of pregnant women suffer from iron-deficiency anemia, which is often caused by a lack of iron. The vast majority of anemia is diagnosed late in pregnancy, as the developing fetus uses up a lot of iron from the mother, the study authors explained.
In the study, researchers collected data on nearly 300,000 mothers and more than 500,000 children born in Sweden between 1987 and 2010. Among the nearly 6% of mothers diagnosed with anemia, only 5% had the condition diagnosed early in pregnancy -- before the 31st week.
For the women diagnosed with anemia early in pregnancy, about 5% of their children went on to be diagnosed with autism, compared with 3.5% of the children of mothers without anemia. For ADHD it was 9.3% versus just over 7%, and for intellectual disability, 3% versus 1.3%, respectively.
After taking into account income level and maternal age, the risk for autism in children born to mothers with anemia early in a pregnancy was 44% greater than children born to mothers without anemia, the team reported. The risk of ADHD was 37% higher, and the risk for intellectual disability was 120% higher, Gardner's team found.
These risks were only associated when anemia occurred before the 30th week of pregnancy and not after, according to the report published online Sept. 18 in JAMA Psychiatry.
Gardner's team said it's possible that maternal iron deficiency early in pregnancy might somehow affect the developing fetal brain, so pregnant women may need iron supplements. Still, more research is needed to confirm that, the team added.
Dr. Ruth Milanaik directs neonatal developmental follow-up programs at Cohen Children's Medical Center in New Hyde Park, N.Y. Reviewing the findings, she said that "maternal nutrition is extremely important as mothers are providing the building blocks for their child's development and this development includes all systems of the body including a child's brain and nervous system."
Milanaik believes that, "considering the rapid growth of the body and mind in the early stages of pregnancy, Dr. Gardner's important findings reaffirm the need for proper nutritional support for all pregnant women during these developmentally vulnerable times."
The March of Dimes has more about anemia in pregnancy.