Background: Iron deficiency, the most common cause of anaemia in pregnancy worldwide, can be mild, moderate or severe. Severe anaemia can have very serious consequences for mothers and babies, but there is controversy about whether treating mild or moderate anaemia provides more benefit than harm.
Objectives: To assess the effects of different treatments for iron-deficiency anaemia in pregnancy (defined as haemoglobin less than 11 g/dl) on maternal and neonatal morbidity and mortality.
Search strategy: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2007), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2005, Issue 4), MEDLINE (1966 to December 2005), EMBASE (1976 to December 2005), LILACS (1982 to 40 edition), BIOSIS Previews (1980 to June 2002) and ongoing clinical trial registers.
Selection criteria: Randomised controlled trials comparing treatments for iron-deficiency anaemia in pregnancy.
Data collection and analysis: We identified 17 trials, involving 2578 women. We assessed trial quality.
Main results: The trials were small and generally methodologically poor. They covered a very wide range of differing drugs, doses and routes of administration, making it difficult to pool data. Oral iron in pregnancy showed a reduction in the incidence of anaemia (one trial, 125 women; relative risk 0.38; 95% confidence interval 0.26 to 0.55). It was not possible to assess the effects of treatment by severity of anaemia. A trend was found between dose and reported adverse effects. We found that most trials had no assessments on relevant clinical outcomes and a paucity of data on adverse effects, including some that are known to be associated with iron administration. Although the intramuscular and intravenous routes produced better haematological indices in women than the oral route, no clinical outcomes were assessed and there were insufficient data on adverse effects, for example, on venous thrombosis and severe allergic reactions.
Authors' conclusions: Despite the high incidence and burden of disease associated with this condition, there is a paucity of good quality trials assessing clinical maternal and neonatal effects of iron administration in women with anaemia. Daily oral iron treatment improves haematological indices but causes frequent gastrointestinal adverse effects. Parenteral (intramuscular and intravenous) iron enhances haematological response, compared with oral iron, but there are concerns about possible important adverse effects. Large, good quality trials, assessing clinical outcomes (including adverse effects) are required.