U.S. infant mortality rates (deaths under one year of age per 1,000 live births) are about 42 percent higher than the comparable country average. Differential reporting methods are likely a factor: a recent working paper from the National Bureau of Economic Research (NBER) found that data difference may explain about 40 percent of the difference in infant mortality rates between the U.S. and comparable countries.
While differences in data collection may explain some of the difference in mortality rates, assuming that collection methods have not changed considerably overtime, the differences should not affect the relative rates of change overtime. From 2000 to 2013, the infant mortality rate in the U.S. improved by about 13 percent, while the comparable country average improved about 26 percent.
The infant mortality rate among all races in the U.S. declined about 14 percent from 2000 to 2013. Non-Hispanic blacks saw about a 18 percent decrease during this time period but continue to have the highest infant mortality rate among all races. American-Indian and Alaska Natives experienced an 8 percent decrease in infant mortality during this time period, and more importantly the infant mortality rates have fluctuated and this was the first major decrease in recent years. Rates among Non-Hispanic blacks, American-Indian and Alaska Natives are higher than average.
Neonatal deaths are deaths which occur less than 28 days after birth. The U.S. has about 66 percent more neonatal deaths than the comparable country average. Some of the variation in infant and neonatal mortality rates is due to variations among registering practices of premature infants. Most countries have no gestational age or weight limits, while some countries specify limits based on some combination of gestational age, birth weight and survival.
From 2000 to 2013, neonatal deaths (deaths less than 28 days after birth) decreased by 13 percent in the U.S. and by 23 percent in comparable OECD countries. A working paper from the National Bureau of Economic Research attributes the difference to health conditions at birth. In 2013, 11 percent of live births in the U.S. were preterm, and about two-thirds of all infant deaths in the U.S. occurred within that preterm group.
From 2000-2013, non-Hispanic Blacks saw the greatest percent change in the neonatal mortality rate (about an 18 percent decrease), but continue to have much higher neonatal mortality rates than all other races/ethnicities in the U.S. (about 88% more). In 2013, the neonatal mortality rate for non-Hispanic Blacks was more than twice the rate (about 125% more) for non-Hispanic Whites.
The United States has slightly fewer perinatal deaths than comparable OECD countries. Perinatal mortality measures deaths within one week of birth (early neonatal deaths), as well as fetal deaths of a minimum gestation period of 28 weeks or minimum fetal weight of 1000g. It should be noted that there are variations in the definition of fetal deaths between some countries. For example, in the U.S., federal guidelines recommend reporting fetal deaths for birth weight over 350 g or those having more than 20 weeks gestation. In contrast, Japan registers all live births, regardless of gestation period.
Postneonatal mortality in the U.S. is measured as deaths occurring between 28 days to under 1 year after birth. In the U.S., postneonatal mortality rates are twice as high among non-Hispanic Blacks, American Indian and Alaska Natives than all other races in the U.S. A working paper by the National Bureau of Economic Research characterizes postneonatal mortality inequality in the U.S. as “lower education groups, unmarried and African-American women having much higher infant mortality rates,” reporting that high postneonatal mortality rates among disadvantaged groups is almost entirely the reason these rates are higher in the U.S. than in Austria and Finland (comparable countries highlighted in the NBER report).
In 2013, 69 percent of all infant deaths in the U.S. were attributed to the 10 leading causes. The top 2 causes, congenital malformations and low birth rate, accounted for about 38 percent of all infant deaths in the U.S.