Many of the trials were from low-income countries; they were generally small and frequently 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 (risk ratio 0.38, 95% confidence interval 0.26 to 0.55, one trial, 125 women) and better
haematological indices than placebo (two trials). It was not possible to assess the effects of treatment by severity of anaemia. A trend was
found between dose and reported adverse effects.Most trials reported no clinically relevant outcomes nor adverse effects.