文档介绍：Taking iron daily during pregnancy is associated with a significant increase in birth weight and a reduction in risk of low birth weight, finds a new study. The effects were seen for iron doses up to 66 mg per day. The World anization currently mends a dose of 60 mg per day for pregnant women.
 
Iron deficiency is the most widespread nutritional deficiency in the world. It is the mon cause of anemia(贫血) during pregnancy, especially in low and middle e countries, affecting an estimated 32 million pregnant women globally in 2011.
 
Studies suggest an association between prenatal anemia and risk of premature (preterm) birth, but evidence on other birth es is inconsistent. The effect of prenatal iron use on adverse birth es is also unclear.
 
So researchers in the UK and US analysed the results of over 90 studies (a mix of randomised trials and cohort studies) of prenatal iron use and prenatal anemia, involving nearly two million women.
 
Iron use increased a mother's average haemoglobin(血红蛋白) pared with controls and significantly reduced the risk of anemia.
 
There was no reduction in risk of preterm birth as a result of iron use. However analysis of cohort studies showed a significantly higher risk of low birth weight and preterm birth with anemia in the first or second trimester of pregnancy.
 
Further analysis indicated that for every 10 mg increase in iron dose per