inclusion criteria for this review
• Type of studies. Randomised and quasi- randomised trials.
• Type of intervention. Prenatal iron or iron + folic acid for prevention of anaemia in pregnant women at any gestational age.
• Type of comparison. ‘Placebo’ or ‘no intervention’. In case where studies assessed the effects of mul-
tiple combinations of vitamins and minerals, those groups were included where iron/iron–folate was the only difference among the study groups (arms).
• Type of outcomes. Maternal: anaemia at term (Hb < 110 g/L), iron deficiency anaemia at term (Hb < 110 g/L and at least one additional labora- tory indicator), maternal mortality, postpartum haemorrhage, need for blood transfusion and pre-eclampsia. Infant: low birthweight, weight at birth, preterm birth (in grams), perinatal death and congenital malformation.
• Location. Studies from both developed and devel- oping countries were included.