The timing of anemia in pregnancy can make a big difference for the developing fetus and may be linked to learning disabilities in children later in life, new study says.
An estimated 15-20 percent of pregnant women worldwide suffer from iron deficiency anemia, a lowered ability of the blood to carry oxygen that is often caused by a lack of iron. The vast majority of anemia diagnoses are made toward the end of pregnancy when the rapidly growing fetus takes up a lot of iron from the mother, according to Neuroscience News. The research was supported by grants from the Swedish Research Council and from the Strategic Research Area Neuroscience at Karolinska Institutet.
In the current study, the researchers examined what impact the timing of an anemia diagnosis had on the fetus’ neurodevelopment. They tried to find out if there was an association between an earlier diagnosis in the mother and the risk of intellectual disability (ID), autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in the child.
In this study of nearly 300,000 mothers and more than half a million children born in Sweden between 1987-2010, less than 1 percent of all mothers were diagnosed with anemia before the 31st week of pregnancy. Among the 5.8 percent of mothers who were diagnosed with anemia, only 5 percent received their diagnosis early on.
The researchers found that children born to mothers with anemia diagnosed before the 31st week of pregnancy had a somewhat higher risk of developing autism and ADHD and a significantly higher risk of intellectual disability compared to healthy mothers and mothers diagnosed with anemia later in pregnancy. Among the early anemic mothers, 4.9 percent of the children were diagnosed with autism compared to 3.5 percent of children born to healthy mothers, 9.3 percent were diagnosed with ADHD compared to 7.1 percent, and 3.1 percent were diagnosed with intellectual disability compared to 1.3 percent of children to non-anemic mothers.
After considering other factors such as income level and maternal age, the researchers concluded that the risk of autism in children born to mothers with early anemia was 44 percent higher compared to children with non-anemic mothers, the risk of ADHD was 37 percent higher and the risk of intellectual disability was 120 percent higher. Even when compared to their siblings, children exposed to early maternal anemia were at higher risk of autism and intellectual disability. Importantly, anemia diagnosed after the 30th week of pregnancy was not associated with a higher risk for any of these conditions.
The researchers emphasize the importance of early screening for iron status and nutritional counselling but note that more research is needed to find out if early maternal iron supplementation could help reduce the risk of neurodevelopmental disorders in children.