The rate of infant mortality is defined as the number of infant deaths within the first year of life per 1,000 live births per year. The rate of infant mortality in the U.S. has declined dramatically since the beginning of the century. Perinatal deaths includes fetal deaths plus deaths to infants who die within the first 28 days of life. Neonatal deaths occur to infants after 28 days of life but before the first year. Each fetal death, live birth, and infant death is recorded on state fetal death certificates, birth certificates and death certificates.
Most states have a linked infant birth and death database to help track infant mortality.
The NVSS is a data collection system designed to provide information on all infant deaths that occur in the United States. These data include information on the infant's age, gender, race and ethnic origin, and cause of death.