Systematic review of randomized trials of the effect of iron supplementation on iron stores and oxygen carrying capacity in pregnancy.
BACKGROUND
Anemia in pregnancy affects 25% of all pregnancies in Europe with iron deficiency affecting even more. Despite supplementation, iron deficiency persists. This review will assess the effect on serum ferritin (iron stores) and hemoglobin (oxygen-carrying capacity) following iron supplementation in pregnant women with anemic and non-anemic iron deficiency.


METHODS
A systemic search of electronic databases and trial registers was conducted from inception to January 2014. Randomized controlled trials of iron supplementation that measured serum ferritin and hemoglobin levels before and after supplementation were selected. Two independent reviewers selected studies, extracted data and assessed quality. Descriptive analyses were carried out.


RESULTS
The review included 23 randomized controlled trials (3525 women). In iron deficiency anemia, more studies described statistically significant increases in serum ferritin levels than in hemoglobin levels following intravenous iron supplementation. In non-anemic iron deficiency there were more statistically significant increases in serum ferritin levels than in hemoglobin levels following oral supplementation. There were no studies reporting maternal quality of life outcomes.


CONCLUSIONS
Serum ferritin appears to change more than hemoglobin following iron supplementation. The clinical effects of this need further investigation.
Women's Health Research Unit, Barts and the London School of Medicine, Queen Mary University of London, London, UK.|Barts Health NHS Trust, London, UK.
Jahnavi
http://orcid.org/0000-0001-5816-2609
J
Daru
Women's Health Research Unit, Barts and the London School of Medicine, Queen Mary University of London, London, UK.|Barts Health NHS Trust, London, UK.
Natalie A M
http://orcid.org/0000-0003-1929-833X
NA
Cooper
Women's Health Research Unit, Barts and the London School of Medicine, Queen Mary University of London, London, UK.|Barts Health NHS Trust, London, UK.
Khalid S
http://orcid.org/0000-0001-5084-7312
KS
Khan
D061605:Administration, Intravenous; D000284:Administration, Oral; D018798:Anemia, Iron-Deficiency / Q000097:blood* / Q000517:prevention & control; D019587:Dietary Supplements; D005260:Female; D005293:Ferritins / Q000097:blood*; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007501:Iron / Q000008:administration & dosage* / Q000378:metabolism*; D000090463:Iron Deficiencies; D011247:Pregnancy; D016032:Randomized Controlled Trials as Topic
D006454:Hemoglobins; D005293:Ferritins; D007501:Iron
Iron deficiency anemia; hemoglobin; non-anemic iron deficiency; pregnancy; serum ferritin