Definition
The infant mortality rate is the probability (expressed as a rate per 1,000 live births) of a child born in a specified year dying before reaching the age of one if subject to current age-specific mortality rates.
Goal/target addressed
Goal 4. Reduce child mortality.
Target 5. Reduce by two-thirds, between 1990 and 2015, the under-five mortality rate.
Rationale
Although the target relates specifically to under-five mortality, infant mortality is relevant to the monitoring of the target since it represents an important component of under-five mortality.
Infant mortality rates measure child survival. They also reflect the social, economic and environmental conditions in which children (and others in society) live, including their health care. Because data on the incidences and prevalence of diseases (morbidity data) frequently are unavailable, mortality rates are often used to identify vulnerable populations.
Method of computation
The indicator is the number of deaths of infants under one year of age in the indicated year per 1,000 live births in the same year.
For data from vital statistics registrations (when reliable), the number of live births and deaths in the same year of children under one year old are estimated. The number of deaths is divided by the number of births and the result is multiplied by 1,000.
For data from household surveys, infant mortality estimates are obtained directly (using birth history, as in Demographic and Health Surveys) or indirectly (Brass method, as in Multiple Indicator Cluster Surveys). When estimated indirectly the under-one mortality estimates must be consistent with the under-five mortality estimates.
Data collection and source
The best source of data is a complete vital statistics registration system—one covering at least 90 percent of vital events in the population. Such systems are uncommon in developing countries, so estimates are also obtained from sample surveys or derived by applying direct and indirect estimation techniques to registration, census or survey data. A wide variety of household surveys, including Multiple Indicator Cluster Surveys and Demographic and Health Surveys, are used in developing countries.
References
The State of the World’s Children, annual, United Nations Children’s Fund (www.unicef.org/publications).
World Health Organization, www3.who.int/whosis.
World Development Indicators, annual, World Bank (www.worldbank.org/data).
Human Development Report, annual, United Nations Development Programme (www.undp.org).
Periodicity of measurement
Vital statistics are typically available once a year, but they are unreliable in most developing countries. Household surveys that include questions on births and deaths are usually conducted every three to five years.
Gender issues
Girls have a survival advantage over boys during the first year of life, largely based on biological differences. This is especially so during the first month of life when perinatal conditions are most likely to be the cause or a contributing cause of death. While infant mortality is generally higher for boys than for girls, in some countries girls’ biological advantage is outweighed by gender-based discrimination (see also indicator 13, Under-five mortality rate). However, under-five mortality better captures the effect of gender discrimination than infant mortality, as nutrition and medical interventions are more important after age one.
Disaggregation issues
Infant mortality generally shows large disparities across geographical areas and between urban and rural areas. Infant mortality may also vary across socioeconomic groups, and this indicator is often used as a general indicator of social distress in populations. Infants in some ethnic groups might also be at higher risk of malnutrition, poorer health and higher mortality. However, showing and analyzing data on specific ethnic groups may be a sensitive issue in the country. Gender differences may also be more pronounced in some social and ethnic groups.
International data comparisons
Mortality rates are among the most frequently used indicators to compare levels of socioeconomic development across countries. The United Nations Population Division, the United Nations Children’s Fund and the World Health Organization regularly produce estimates of under-five mortality based on available national data. These data series may differ, however, because of differences in methodologies used to estimate data and differences in reporting periods.
The State of the World’s Children, annual, United Nations Children’s Fund (www.unicef.org/publications).
World Health Organization, www3.who.int/whosis.
World Development Indicators, annual, World Bank (www.worldbank.org/data).
Human Development Report, annual, United Nations Development Programme (www.undp.org).
Comments and limitations
The infant mortality rate is considered to be a more robust estimate than the under-five mortality rate if the information is drawn from vital statistics registration.
In developing countries, household surveys are essential to the calculation of this indicator, but there are some limits to their quality. Survey data are subject to recall error, and surveys estimating infant deaths require large samples, because such incidences are uncommon and representative households cannot ordinarily be identified for sampling. Moreover, the frequency of the surveys is generally only every three to five years. Therefore, when using household survey estimates, it is important to take sampling errors into account.
Agencies
Ministries of health.
National statistical offices.
United Nations Children’s Fund.
World Health Organization.