“Daily iron in pregnancy reduces small baby risk,” BBC News reports, with a similar story in the Daily Express.
The news stories follow a major review of the best available evidence on the link between use of iron supplements during pregnancy, and pregnancy and birth outcomes.
The pooled results suggest that, compared with no supplements, taking iron supplements increases the mother’s haemoglobin levels, and halves the risk of the mother becoming anaemic during pregnancy.
Supplements also resulted in the baby being on average 41.2g heavier at birth and reduced the risk of low birthweight by 19%. The findings showed a dose-response relationship, with higher doses being associated with lower risk of maternal anaemia and lower risk of low birthweight.
Overall, this offers evidence to back iron supplementation during pregnancy. However, this review focussed on low, middle and high income countries. Women do need increased iron during pregnancy, but in the UK, should be able to get all the iron they need in their diet (such as from leafy vegetables).
Currently, iron supplements are recommended if pregnancy blood tests show that the mother is anaemic. They are not routinely offered to all pregnant women due to the potential for side effects. Folic acid supplements are, however, recommended while trying to conceive and during the first 12 weeks of pregnancy.
Where did the story come from?
The study was carried out by researchers from Harvard School of Public Health, Harvard Medical School and Imperial College, London. Funding was provided by the Bill and Melinda Gates Foundation. Additional support came from the Saving Brains Program, Grand Challenges Canada Grant.
The study was published in the peer-reviewed, British Medical Journal.
The news stories provide a representative view of the findings.
What kind of research was this?
This was a systematic review and meta-analysis. It pooled the results from randomised controlled trials and observational cohort studies that examined the relationship between use of iron supplements during pregnancy, and pregnancy and birth outcomes.
The researchers say that iron deficiency is the most common cause of anaemia during pregnancy worldwide. Because of this, the World Health Organization recommends the use of antenatal iron supplements in low and middle income countries, and it is also recommended in some high income countries.
Observational studies are said to have found suggested links between iron deficiency anaemia and premature birth, and clinical trials have given inconclusive results on the link between iron levels and birth outcomes.
This review aimed to address this question by identifying all observational studies and clinical trials investigating the issue, and pooling the results in meta-analysis to see whether there is a link between use of iron supplements during pregnancy and haemoglobin levels in the mother and birth outcomes. A systematic review is the best way to examine the current evidence related to this issue.
What did the research involve?
The researchers conducted a search across medical databases up to May 2012, including randomised controlled trials in pregnant women investigating the use of daily oral iron or iron and folic acid supplements compared with inactive placebo pill or no treatment.
They excluded trials that investigated multiple vitamins or minerals, or in women with significant illnesses (such as mothers infected with HIV). Trials were required to have examined maternal outcomes such as anaemia (defined as haemoglobin <110g/l) and iron deficiency (defined as serum ferritin <12 micrograms/l), and birth outcomes, such as premature birth, birthweight and infant death around the time of birth. Their search also included observational cohort studies that prospectively followed the association between baseline anaemia and birth outcomes. The researchers assessed the quality of included studies, and pooled their results where possible, taking into account the differences between the findings of the individual studies (heterogeneity). Source: Read More at NHS