Iron Deficiency Anaemia in Pregnancy: A Narrative Review from a Clinical Perspective

Abstract

Anaemia in pregnancy is a global problem of significance in all settings. The most common cause is iron deficiency. Large numbers of women are affected, ranging up to 25-30% antenatally and 20-40% postnatally. It is associated with serious adverse outcomes for both the mother and her baby. The risk of low birth weight, preterm birth, postpartum haemorrhage, stillbirth, and neonatal death are all increased in the presence of anaemia. For the infants of affected pregnancies, complications may include neurocognitive impairment. Making an accurate diagnosis during pregnancy has its challenges, which include the choice of thresholds of haemoglobin below which a diagnosis of anaemia in each trimester of pregnancy can be made and, aligned with this question, which are the most appropriate biomarkers to use to define iron deficiency. Treatment with oral iron supplements increases the haemoglobin concentration and corrects iron deficiency. But high numbers of women fail to respond, probably due to poor adherence to medication, resulting from side effects. This has resulted in an increased use of more expensive intravenous iron. Doubts remain about the optimal regimen to of oral iron for use (daily, alternate days, or some other frequency) and the cost-effectiveness of intravenous iron. There is interest in strategies for prevention but these have yet to be proven clinically safe and effective.

Keywords: anaemia; hepcidin; iron; outcomes; physiology; pregnancy; prevention; stillbirth; threshold; treatment.

Figure 1

With permission. The U-shaped curve of iron’s adequacy range compared with other nutrients. The blue line indicates the wide range for which most nutrients doses are considered to be adequate. The range for iron, shown by the red line, is narrower and can with much smaller variation in dose easily fall into deficient or toxic ranges [51].