Iron supplements given during pregnancy are known to prevent deaths in newborns, which has been validated by studies in China. "After comparing our results with other studies in Indonesia, India, the US and Bangladesh, it appeared the reduction in neonatal mortality was related to the increased duration of pregnancy from the iron in the supplements," said Michael Dibley of the University of Sydney, who was associated with the study. Hong Yan, the study's principal investigator, from Xi'an Jiaotong University College of Medicine, said: "Our research demonstrates that nutrient supplements for pregnant women in developing countries need to have an adequate amount of iron to prevent premature births and reduce infant mortality." In China, the most populated country, neonatal mortality accounts for more than 50 percent of the deaths of children under five. Children with low birth weight are at a higher risk of mortality, and one of the major causes of low birth weight in developing countries is the poor nutritional status of the mother before and during pregnancy, said a Sydney University release. "It is estimated that 1.2 million low weight babies are born each year in China, however there are not yet any specific policies or programmes for the distribution of multiple micronutrient or iron/folic acid supplements during pregnancy, even to disadvantaged women," Dibley added. The study, which took place over four years in two poor rural counties in northwest China, assessed the impact of taking iron/folic acid and multiple micronutrient supplements (containing 15 minerals and vitamins) during pregnancy, compared with folic acid alone.