Infant mortality is the death of infants in the first year of life. The leading causes of infant mortality are dehydration and disease. Major causes of infant mortality in more developed countries include congenital malformation, infection and SIDS. The most common cause of infant mortality of all children around the world has traditionally been dehydration from diarrhea. Because of the success of spreading information about Oral Rehydration Solution (a mixture of salts, sugar and water) to mothers around the world, the rate of children dying from dehydration has been decreasing and has become the second most common cause in the late 1990s. Currently the most common cause is pneumonia. www.wikipedia.org