Iron is a vital nutrient for cellular functions, especially during pregnancy, where its demand increases significantly due to the expansion of maternal blood volume and the development of the fetus.
Iron is a vital nutrient for cellular functions, especially during pregnancy, where its demand increases significantly due to the expansion of maternal blood volume and the development of the fetus.
Iron deficiency in pregnant women can lead to severe consequences, including maternal illness, low birth weight, prematurity, and intrauterine growth restriction. The fetal brain is particularly vulnerable to iron deficiency, which can be exacerbated by maternal conditions such as hypertension, smoking, or glucose intolerance. Research has linked low maternal iron intake to neurodevelopmental disorders in children, including autism and schizophrenia.
Iron is crucial for the fetus to meet its metabolic needs and to build iron stores for the first six months of life. Iron deficiency is prevalent, affecting up to 80% of pregnant women in low- and middle-income countries and around 45% in wealthier nations. The placenta also requires significant iron and can store it to mitigate maternal deficiencies. Adequate fetal iron loading is vital to prevent postnatal iron deficiency, which is associated with long-term neurodevelopmental issues.
Anaemia is a late-stage indicator of iron deficiency, as iron is prioritised for red blood cell production over other tissues, including the brain. Biomarkers like serum ferritin are more sensitive for assessing iron status than haemoglobin levels alone, which may overlook early deficiency stages.
Routine screening for iron status in newborns is often neglected, despite the high prevalence of iron deficiency. Delayed cord clamping can enhance iron levels in neonates, providing sufficient iron for growth in the first few months. While haemoglobin concentration is commonly used to assess iron status, it is not sensitive enough to detect early deficiency, which can lead to anemia. Other biomarkers, such as serum ferritin, total iron binding capacity saturation (%TSAT), and hepcidin, are more effective in diagnosing iron deficiency anemia (IDA) and distinguishing it from other causes of anemia.
Iron deficiency and IDA are not synonymous. IDA occurs when iron deficiency leads to anaemia. Non-anaemic stages of deficiency can still impair tissue function, including brain development. Children with pre-anaemic iron deficiency may face cognitive and behavioural issues, highlighting the importance of iron for brain health even before anaemia develops.
Conclusion
The consequences of maternal iron deficiency can have immediate and long-term effects on fetal brain development, potentially leading to altered brain structure and cognitive dysfunction in children, even if iron levels normalise later. Low iron status in infancy is associated with developmental delays and increased risks of mental health issues later in life.
Reference
Georgieff, Michael K. Iron Deficiency in Pregnancy. Am J Obstet Gynecol. 2020;223(4): 516–524. doi:10.1016/j.ajog.2020.03.006.
