Iron deficiency in pregnancy and the baby's brain
What it found
Iron deficiency is common in pregnancy and is linked to problems for the baby, including effects on brain development that can last.
The authors say iron in pregnancy matters for the child's brain across life.
What they found
Studies in people
How common in pregnancy
In low- and middle-income countries the rate of iron deficiency in pregnancy approaches 80%. In well-resourced countries it approaches 45%, depending on how sensitive the test used is.
Brain effects in newborns
Newborns with low cord blood ferritin had poorer recognition memory and slower speed of processing. These were seen at birth and at 2 months of age.
Longer term in children
Low iron status as a newborn was linked to poorer recognition memory at 3.5 to 4 years, poorer school performance at 5 to 6 years, and difficulty with planning and attention at 10 years.
Autism and schizophrenia
Low iron intake around conception was linked to a higher risk of autism in the child. Low iron intake in the second trimester was linked to a 30% higher risk of schizophrenia.
Animal and lab studies
What animal studies show
In animal studies, low iron before birth changed brain chemicals, energy use, myelin and gene activity. Some of these changes lasted into adulthood even after iron was restored.
Other findings
Why pregnancy raises need
Pregnancy needs an extra 1 gram of iron, split fairly evenly between mother and fetus. Each extra gram of hemoglobin the mother makes needs another 3.46 milligrams of elemental iron.
What the authors conclude
“This life-cycle approach to nutrition can be seen as an investment in the mental health of the next generation and an investment in society.”
Also in their conclusions
- They say the conversation about nutrition and childhood brain health should shift from postnatal nutrition to prenatal and even pre-conception nutrition.
- They argue for policies that promote maternal nutritional health heading into pregnancy, followed by close attention to providing critical nutrients such as iron during pregnancy.
- They describe this life-cycle approach as an investment in the mental health of the next generation and in society.
How it was done
Iron is needed by all cells, and pregnancy raises the mother's need for iron a lot. The authors wanted to set out how to spot and prevent iron deficiency in pregnancy and what it means for the baby's brain and mental health.
They pulled together existing research on iron in pregnancy, including studies in pregnant women and their children, and lab and animal studies on how iron shortage affects the developing brain.
What it can’t tell you
- Many of the findings come from studies that follow people over time, which can show a link but not prove cause and effect.
- Some of the evidence comes from animal studies, which cannot show what happens in people.
- The authors note that more adequately powered studies are needed before policy decisions can be made about giving iron to pregnant women who are not deficient.
Who paid
- Funding
- Funded by NICHD NIH HHS; NINDS NIH HHS (from the PubMed record).
- Conflicts
- The author has no conflicts of interest to report.
- Authors work at
- University of Minnesota Medical School, MN
The paper
- Title
- Iron deficiency in pregnancy
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Georgieff MK (2020). Iron deficiency in pregnancy. American journal of obstetrics and gynecology. doi:10.1016/j.ajog.2020.03.006Free full textPubMed 32184147DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error