Child Mortality

WHILE THE TERMS child mortality and infant mortality are often used interchangeably, technically they are not the same thing. Infant mortality refers to the incidence of death among infants in their first year of life, whereas child mortality also refers to deaths of older children. Demographers define the infant mortality rate as the annual number of deaths among infants less than a year old per 1,000 births, whereas the child mortality rate usually refers to deaths prior to the fifth birthday. [Page 148]It is useful to draw a distinction between the two types of rates as the likelihood of death is not nearly as high among children as it is among infants. Both of these age-specific mortality rates are widely considered among the most valuable indicators of societal development.

The risk of dying during the first few years of life has varied dramatically across societies and over time. For example, throughout most of human history, child mortality was almost universally high. Reasonable estimates indicate that about 30 percent of all births in premodern societies would have died in infancy. With the epidemiological transition of the 19th and 20th centuries, mortality declined dramatically, such that the vast majority of births in most societies now survive to adulthood. Yet there are important exceptions to this general rule, as high rates of death and disease continue to characterize the young in many parts of the world.

As an example of high child mortality, the United Nations has estimated for sub-Saharan Africa that overall, about 17 percent of all births in 2003 are not expected to survive to their fifth birthday. The situation is even worse in selected countries of equatorial Africa, as for example in Sierra Leone, where the comparable figure is about 28 percent of all births. While poverty is closely linked with high mortality, a variety of other interrelated factors are also important, including the relative success of public health initiatives, improvements in sanitation systems, water quality, the availability of modern medicines, antibiotics, vaccines, and the control of communicable diseases. The extraordinarily high child mortality that characterized Sierra Leone occurred in an already impoverished country that encountered drought, famine, and a breakdown in social order because of a violent and prolonged civil war.

Across affluent nations in the 21st century, the risk of death in infancy has plummeted to unprecedented low levels. For example, across most Western nations, the percentage of births not surviving the first year of life hovers at about one-half of a percent (slightly above or slightly below five deaths per 1,000 births). In this low mortality context, it is really the short period of time, just before or after birth that is most dangerous for infants. For this reason, there are special measures of infant death that assist in more clearly identifying the etiology of mortality. It is possible to distinguish between neonatal mortality (which refers to deaths of infants within 28 days after birth) and postneonatal mortality (which covers deaths from 28 days to one year).

When infant mortality is very low, as is true throughout most Western nations, neonatal deaths comprise a large proportion of all infant deaths. On the other hand, postneonatal deaths are more common in poor countries, as they are more closely linked with poverty, inadequate diet, viral and bacterial risks, as well as injuries. In rich countries, most infant deaths relate to processes associated with gestation and birth, including premature birth, low birth weight, congenital anomalies, as well as obstetrical hazards associated with delivery.

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