RESEARCH Impact of micronutrient supplementation during pregnancy on birth weight, duration of gestation, and perinatal mortality in rural western China: double blind cluster randomised controlled trial Lingxia Zeng, researcher/lecturer,1 Yue Cheng, PhD candidate,1 Shaonong Dang, researcher/lecturer,1 Hong Yan, professor/dean,1 Michael J Dibley, associate professor, professorial fellow,2,3 Suying Chang, associate professor,4 Lingzhi Kong, professor5 1 Department of Public Health, Xi’an Jiaotong University College of Medicine, PO Box 46, Xi’an, Shaanxi 710061, China 2 School of Public Health, University of Sydney, Room 307A, Edward Ford Building (A27), University of Sydney, NSW 2006, Australia 3 George Institute for International Health, PO Box M201, Sydney, NSW 2050, Australia 4 Chinese Centre for Disease Control and Prevention, Beijing 100050, China 5 Bureau for Disease Prevention and Control, Ministry of Health, Beijing 100044, China Correspondence to: H Yan
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Cite this as: BMJ 2008;337:a2001 doi:10.1136/bmj.a2001
BMJ | ONLINE FIRST | bmj.com
ABSTRACT Objective To examine the impact of antenatal supplementation with multiple micronutrients or iron and folic acid compared with folic acid alone on birth weight, duration of gestation, and maternal haemoglobin concentration in the third trimester. Design Cluster randomised double blind controlled trial. Setting Two rural counties in north west China. Participants 5828 pregnant women and 4697 live births. Interventions Villages were randomised for all pregnant women to take either daily folic acid (control), iron with folic acid, or multiple micronutrients with a recommended allowance of 15 vitamins and minerals. Main outcome measures Birth weight, length, and head circumference measured within 72 hours after delivery. Neonatal survival assessed at the six week follow-up visit. Results Birth weight was 42 g (95% confidence interval 7 to 78 g) higher in the multiple micronutrients group compared with the folic acid group. Duration of gestation was 0.23 weeks (0.10 to 0.36 weeks) longer in the ironfolic acid group and 0.19 weeks (0.06 to 0.32 weeks) longer in the multiple micronutrients group. Iron-folic acid was associated with a significantly reduced risk of early preterm delivery (
