The infant mortality rate correlates very strongly with and is among the best predictors of
state failure.
[1] 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 index. But the method of calculating IMR often varies widely between countries based on the way they define a live birth. The
World Health Organization (WHO) 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 IMR's can be problematic for comparisons.
A well documented example illustrates this problem. Historically, until the 1990's
Russia and the
Soviet 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 7 days.
[2] Although such extremely premature infants typically accounted for only about .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.
[3] In some cases, too, perhaps because hospitals or regional health departments were held accountable for lowering the IMR in their catchment area, infant 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.
[4]
Another challenge to comparability is the practice of counting frail or premature infants who die before the normal due date as
miscarriages (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 Coale, 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.
[5]
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