World infant mortality rates in
is defined as the number of
deaths (one year of age or younger)
per 1000 live births. The most common cause worldwide has
traditionally been due to dehydration
. However, the spreading
information about Oral
(a mixture of salts, sugar, and water) to
mothers around the world has decreased the rate of children dying
from dehydration. Currently the most common cause is pneumonia
. Other causes of infant mortality
include malnutrition, malaria, congenital malformation
, child abuse
, and neglect
contribute to infant mortality.Related statistical categories:
- Perinatal mortality
only includes deaths between the foetal viability (22 weeks
gestation) and the end of the 7th day after delivery.
- Neonatal mortality only includes deaths in the first
28 days of life.
- Postneonatal mortality only includes deaths after 28
days of life but before one year.
- Child mortality
includes deaths within the first five years after birth.
Infant mortality throughout history
World historical and predicted infant mortality rates per
1,000 births (1950-2050)
UN, medium variant, 2008 rev.
During ancient times
, the infant mortality rate
was about 200 deaths per 1,000 live births and the under-5
mortality rate was about 300 deaths per 1,000 live births.
Infant mortality rate
Infant mortality rate
(IMR) is the number of
newborns dying under a year of age divided by the number of live
births during the year times 1000. The infant mortality rate is
also called the infant death rate. It is the number of deaths that
occur in the first year of life for 1000 live births.
In past times, infant mortality claimed a considerable percentage
of children born, but the rates have significantly declined in the
West in modern times, mainly due to improvements in basic health
care, though high technology medical advances have also helped.
Infant mortality rate is commonly included as a part of standard of living
The infant mortality rate is reported as number of live newborns
dying under a year of age per 1,000 live births, so that IMRs from
different countries can be compared.
Comparing infant mortality rates
The infant mortality rate correlates very strongly with and is
among the best predictors of state
. IMR is also a useful indicator of a country's level of
health or development, and is a component of the physical quality of life
. But the method of calculating IMR often varies widely
between countries based on the way they define a live birth and how
many premature infants are born in the country. The World Health Organization
defines a live birth as any born human being who demonstrates
independent signs of life, including breathing, voluntary muscle
movement, or heartbeat. Many countries, however, including certain
European states and Japan, only count as live births cases where an
infant breathes at birth, which makes their reported IMR numbers
somewhat lower and raises their rates of perinatal mortality.
The exclusion of any high-risk infants from the denominator or
numerator in reported IMRs can be problematic for comparisons.
countries, including the United States, Sweden or Germany, count an
infant exhibiting any sign of life as alive, no matter the month of
gestation or the size, but according to United States Centers for Disease Control
researchers, some other countries differ in these practices.
All of the countries named adopted the WHO definitions in the late
1980s or early 1990s, which are used throughout the European Union.
However, in 2009, the US CDC issued a report which stated that the
American rates of infant mortality were affected by the United
States' high rates of premature babies compared to European
countries and which outlines the differences in reporting
requirements between the United States and Europe, noting that
France, the Czech Republic, Ireland, the Netherlands, and Poland do
not report all live births of babies under 500 g and/or 22 weeks of
gestation.However, the report also concludes that the differences
in reporting are unlikely to be the primary explanation for the
United States’ relatively low international ranking.
Another well-documented example also illustrates this problem.
Historically, until the 1990s Russia and the
Union did not count as a live birth or as an infant death
extremely premature infants (less than 1,000 g, less than 28 weeks
gestational age, or less than 35 cm in length) that were born
alive (breathed, had a heartbeat, or exhibited voluntary muscle
movement) but failed to survive for at least seven days.
Although such extremely premature infants typically accounted for
only about 0.005 of all live-born children, their exclusion from
both the numerator and the denominator in the reported IMR led to
an estimated 22%-25% lower reported IMR. In some cases, too,
perhaps because hospitals or regional health departments were held
accountable for lowering the IMR in their catchment area
deaths that occurred in the 12th month were "transferred"
statistically to the 13th month (i.e., the second year of life),
and thus no longer classified as an infant death.
UNICEF uses a statistical methodology to account for reporting
differences among countries. "UNICEF compiles infant mortality
country estimates derived from all sources and methods of
estimation obtained either from standard reports, direct estimation
from micro data sets, or from UNICEF’s yearly exercise. In order to
sort out differences between estimates produced from different
sources, with different methods, UNICEF developed, in coordination
with WHO, the WB and UNSD, an estimation methodology that minimizes
the errors embodied in each estimate and harmonize trends along
time. Since the estimates are not necessarily the exact values used
as input for the model, they are often not recognized as the
official IMR estimates used at the country level. However, as
mentioned before, these estimates minimize errors and maximize the
consistency of trends along time."
Another challenge to comparability is the practice of counting
frail or premature infants who die before the normal due date as
(spontaneous abortions) or
those who die during or immediately after childbirth as stillborn.
Therefore, the quality of a country's documentation of perinatal mortality
can matter greatly
to the accuracy of its infant mortality statistics. This point is
reinforced by the demographer Ansley
, who finds dubiously high ratios of reported stillbirths
to infant deaths in Hong Kong and Japan in the first 24 hours after
birth, a pattern that is consistent with the high recorded sex
ratios at birth in those countries and suggests not only that many
female infants who die in the first 24 hours are misreported as
stillbirths rather than infant deaths but also that those countries
do not follow WHO recommendations for the reporting of live births
and infant deaths.
Another seemingly paradoxical finding is that when countries with
poor medical services introduce new medical centers and services,
instead of declining the reported IMRs often increase for a time.
The main cause of this is that improvement in access to medical
care is often accompanied by improvement in the registration of
births and deaths. Deaths that might have occurred in a remote or
rural area and not been reported to the government might now be
reported by the new medical personnel or facilities. Thus, even if
the new health services reduce the actual IMR, the reported IMR may
Global infant mortality trends
For the world, and for both Less Developed Countries (LDCs) and
More Developed Countries (MDCs), IMR declined significantly between
1960 and 2001. World infant mortality rate declined from 126 in
1960 to 57 in 2001.
However, IMR remained higher in LDCs. In 2001, the Infant Mortality
Rate for Less Developed Countries (91) was about 10 times as large
as it was for More Developed Countries (8). For Least Developed
Countries, the Infant Mortality Rate is 17 times as high as it is
for More Developed Countries. Also, while both LDCs and MDCs made
dramatic reductions in infant mortality rates, reductions among
less developed countries are, on average, much less than those
among the more developed countries.
Infant mortality rate in countries
Nearly two orders of magnitude separate countries with the highest
and lowest reported infant mortality rates. The top and bottom five
countries by this measure (taken from the The World Factbook
's 2009 estimates) are
Afghanistan's infant mortality rate is expected to improved by at
least 60% in the next ten years due to billions of dollars of
States, infant mortality is 630 per 100,000 live births or
6.3 per 1000 live births.
Infant mortality rates in the United
States per 100,000 live births for 10 leading causes of, 2005
- World Infant Mortality Rates in 2008
Population Reference Bureau
- UNdata: Infant mortality rate (per 1,000
- Gabriel Duc, "The crucial role of definition in perinatal
epidemiology," Sozial- und Präventivmedizin/Social and
Preventive Medicine, Vol. 40, No. 6 (November 1995):
- Definition of data collected in the European Union,
see item 8
- In 1991, the Baltic states moved to the WHO standard
definition; in 1993 Russia also moved to this definition.
- UNICEF, State of the World's Children 2003 infant
- United Nations World Population Prospects report,
for the period 2005-2010: 2006 revision – Table A.18, A.19
- CIA World Factbook, last updated on April 2,
- Centers for Disease Control and Prevention -->
QuickStats October 26, 2007 / 56(42);1115, in turn citing: Kung
HC, Hoyert DL, Xu JQ, Murphy, SL. E-stat deaths: preliminary data
for 2005 health E-stats. Hyattsville, MD: US Department of Health
and Human Services, CDC; 2007. Available at