By Anthony J. Brown, MD
NEW YORK (Reuters Health) – The infant mortality rate in 1999 was 7 deaths per 1000 live births, 3% lower than the rate in 1998 and 21% lower than the rate at the start of the decade, according to a report released on Wednesday by the US Centers for Disease Control and Prevention (CDC).
The report, entitled "Infant Mortality Statistics from the 1999 Period Linked Birth/Infant Death Data Set", indicates that the three leading causes of death–congenital malformations, low birthweight, and sudden infant death syndrome (SIDS)–accounted for almost 50% of the infant deaths in 1999.
Socioeconomic factors had a dramatic impact on the risk of infant death, the report notes. Mortality risk was higher among infants with mothers who received little or no prenatal care, were teenagers, had 9 to 11 years of education, were unmarried, or smoked during pregnancy. Infant mortality rates were generally higher in states in the south and lowest for western and northeastern states.
Mortality rates were higher for male infants, infants from multiple births, and those born preterm than other infants, according to the report by the Atlanta-based disease surveillance group.
The report also indicates that the infant death rate varied according to maternal race, even after correcting for socioeconomic factors. The lowest rate, 2.9 deaths per 1000 live births, was found among Chinese mothers, while Black non-Hispanic mothers had the highest infant mortality rate, 14.0 deaths per 1000 live births.
"The leading causes of infant death identified in 1999 have not changed from years past," lead author Dr. T. J. Mathews told Reuters Health. "But there has been a dramatic reduction in the number of SIDS cases and this may, in large part, account for the overall reduction in infant mortality," he said. Improvements in neonatal intensive care have also had a strong impact on the infant mortality rate, he added.
"There are populations in the US whose infant mortality rates are very low," Dr. Mathews noted. "These populations, such as Chinese and Japanese mothers, really set the standard and make us question 'what is it that they're doing right?'" he said. "They are setting a great example of how it should be for all populations in the US."