DefinitionInfant mortality rates are calculated as the number of resident infant deaths occurring in a given infant age group in a given year per 1,000 resident live births in the same year.
NumeratorFor infant mortality: number of deaths of resident infant younger than 1 year of age in a given year.
For neonatal mortality: number of deaths of resident infant younger than 28 days of age in a given year.
For perinatal mortality: number fetal deaths of at least 28 weeks gestation, plus the number of infant deaths less than 7 days old in a given year.
For post-neonatal mortality: number of deaths of resident infants from 28 days of age to less than 1 year in a given year.
DenominatorTotal number of resident live births in the same year.
For perinatal mortality, the denominator is the total number of resident live births plus fetal deaths of at least 28 weeks gestation.
Data Interpretation IssuesThe Infant Mortality Rate is most often calculated as infant deaths in a given year per 1,000 live births in the same year (death period method). The rate may also be calculated as death of infants born in a given year per 1,000 infants born in that year (birth cohort method).
Why Is This Important?The infant mortality rate is often used as an indicator of the level of health and is a commonly-used measure of public health for countries around the world. While the infant mortality rate has been declining in the U.S., in New Mexico the trend has remained fairly level.
Healthy People Objective: MICH-1.3, All infant deaths (within 1 year)U.S. Target: 6.0 infant deaths per 1,000 live births
Other ObjectivesCDC Environmental Public Health Tracking, Nationally Consistent Data and Measures (EPHT NCDM)
How Are We Doing?Overall, congenital malformations, deformations and chromosomal abnormalities are the leading cause of infant death (20.1% of deaths). Disorders related to short gestation and low birth weight are second, making up 16.6% of deaths. However, it is important to keep in mind that cause of death varies over the first year of life, and combining all causes during the first year of life obscures the importance of sudden infant death syndrome as the leading cause of death in the postneonatal period.