New study links anaemia in early pregnancy to higher autism risk in children

Women who suffer from anemia earlier in pregnancy may give birth to children who have a higher risk of ADHD and autism. — DragonImages/Istock.com picture via AFP-Relaxnews
Women who suffer from anemia earlier in pregnancy may give birth to children who have a higher risk of ADHD and autism. — DragonImages/Istock.com picture via AFP-Relaxnews

LONDON, Sept 20 — New European research has found that women who suffer from anaemia in early pregnancy, a condition which is usually more common in late pregnancy, may give birth to children who have a higher risk of autism and attention deficit hyperactivity disorder (ADHD).

Carried out by researchers at the Karolinska Institutet, Sweden, the new study looked at 532,232 Swedish children and their 299,768 mothers to look at what effect the timing of an anaemia diagnosis during pregnancy had on the foetus’ neurodevelopment. In particular, the researchers wanted to investigate if there was an association between an earlier diagnosis of anaemia and a higher risk of intellectual disability (ID), autism, and ADHD in children.

The findings, published in the journal JAMA Psychiatry, showed that children born to mothers who had anaemia diagnosed at the 30th week of pregnancy or before had a higher risk of developing autism, ADHD, and intellectual disability, compared to children born to mothers diagnosed with anaemia later in pregnancy and mothers who were not diagnosed at all. 

More specifically, of the children born to mothers who suffered from anaemia at week 30 or earlier, 4.9 per cent were diagnosed with autism, compared to 3.5 per cent of children born to healthy mothers. In addition, 9.3 per cent were diagnosed with ADHD, and 3.1 per cent were diagnosed with intellectual disability, compared to 7.1 per cent and 1.3 per cent, respectively, of children born to non-anaemic mothers.

After taking into account potentially influencing factors such as the mother’s age and income level, the researchers concluded that children born to mothers with early anaemia had a 44 per cent higher chance of autism compared to children with non-anaemic mothers. The risk of ADHD was 37 per cent higher and the risk of intellectual disability was 120 per cent higher. However, the same associations were not found between these health conditions and anaemia diagnosed toward the end of pregnancy, which the researchers say highlights the importance of early screening to determine a woman’s iron status and if she needs to adjust her iron intake.

The researchers noted that around 15 to 20 per cent of pregnant women worldwide suffer from iron deficiency anaemia, which is when the blood’s ability to carry oxygen is reduced, often due to a lack of iron. However, the large majority of anaemia diagnoses are made toward the end of pregnancy, as the rapidly growing foetus takes up a lot of iron from the mother.

In this study, less than 1 per cent of all mothers were diagnosed with early anaemia.

“A diagnosis of anaemia earlier in pregnancy might represent a more severe and long-lasting nutrition deficiency for the foetus,” says Renee Gardner, the study’s lead researcher. “Different parts of the brain and nervous system develop at different times during pregnancy, so an earlier exposure to anaemia might affect the brain differently compared to a later exposure. “The National Institute of Health in the US recommends 18 mg of iron per day for adult women and 27 mg per day during pregnancy. However, as excessive iron intake can be toxic, pregnant women should discuss their iron intake with their midwife or doctor. — AFP-Relaxnews

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