Infant Mortality Rate

Infant mortality refers to the death of infants in the first year of their life. It is measured by the infant mortality rate (IMR), which is the ratio of the total number of deaths to the number of children under the age of one year for every 1,000 live births. IMR is often broken down into three components based on time of death. First, the perinatal mortality rate measures the ratio of the number of late-fetal deaths (at or after 28 weeks gestation) and deaths within the first 7 days after birth per 1,000 live births. Second, the neonatal mortality rate refers to the ratio of the number of deaths within 28 days after birth (per 1,000 live births). Third, the postneonatal mortality rate is the ratio of the number of deaths from 28 days to the end of the first year per 1,000 live births. The distinction between perinatal, neonatal, and postneonatal mortality is important because the risk of death is higher close to the delivery date, and the causes of death near the time of birth/delivery are quite different from those later in infancy.

Though the world's infant mortality is 54, differences across the world are substantial. Africa's rate (88) is 15 times higher than the average rate (6) for developed countries. Sierra Leone has the highest rate of IMR (165) in Africa. Though on average, the rate for Asia is 56, Afghanistan has highest IMR (172) in the world. On the other hand, Hong Kong's rate (3.2) is very low, illustrating that the most variation in infant mortality level occurs in Asia. Both Europe and North America have low levels of infant mortality, with average rates well under 10.

While the causal relationship between infant mortality and level of socioeconomic development and environmental conditions is not perfect, the infant mortality rate is commonly used as a general indicator of socioeconomic well-being and of general medical and public health conditions in a country. IMR is included as one of the components of “standard of living” evaluations of countries. Developed countries can provide the basic requirements for infant survival namely clean water, sanitary surroundings, adequate food, shelter, and access to basic health care services. On the other hand, the major proportion of infant mortality in underdeveloped countries is due to improper sanitary practices [Page 929]and inadequacies in the diet of mothers, resulting in infectious and communicable diseases.

The causes of infant mortality vary over the time of infant deaths and between developed and underdeveloped countries. Postneonatal mortality, which is predominantly due to socioeconomic and environmental conditions, is more common in underdeveloped countries than developed countries. The major causes are infectious diseases, such as pneumonia, tetanus, malaria, and dehydration. These diseases are in turn consequences of improper sanitation at the place of delivery; traditional types of attendants and practices during prenatal, natal, and postnatal periods; poor nutritional status of lactating mothers; age of mothers; income; and educational levels. At the individual level, mothers (and fathers) with lower income and education are less likely to possess knowledge of sanitary behaviors and the money for adequate food. In addition, they are less likely to take their babies to a health service if needed. This is especially important for information about Oral Rehydration Therapy, which is effective in saving babies from dying from the dehydration that accompanies diarrhea.

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