Infant mortality refers to the number of deaths per 1,000 infants (1 year old or below) in any given nation. It is considered one of several indicators of a nations industrial and social development.
Global infant mortality rankings
All information courtesy of the CIA World Factbook.
Currently, the world's highest infant mortality rates exist in Angola, Sierra Leone, and Afghanistan, while the lowest rate is in the nation of Singapore. The rate within the United States currently stands at or around 6.3 deaths per 1,000 births, placing it at 46th on the list, behind Guam but ahead of the Faroe Islands. The American mortality rate is inflated by three significant factors; firstly the US measures all infants that show any sings of life as live births, versus waiting 5 minutes or 1 hour before considering a birth live, secondly illegal immigrants have much higher rates of infant mortality and their inclusion in the numbers raises them significantly, thirdly religious opposition to abortion means that more high risk pregnancies are carried to term. Without these compounding factors the US would be near the top of the list.