Many more babies die in the United States than you might think. In 2014 more than 23,000 infants died in their first year of life in the United States, or about six for every 1,000 born. According to the Centre for Disease Control and Prevention, 25 other industrialized nations do better than the United States at keeping babies alive.

Infant mortality is the topic of this week's Healthcare Triage.

Our high infant mortality is hard for some to comprehend. Some will argue that the disparity isn't real. They'll assert that the United States counts very premature babies as infants and others don't because we have better technology and work harder to save young lives. 

Therefore, they say, our increased rate of infant death isn't due to deficiencies but differences in classification. These differences aren't as common or as great as many people think. Even when you exclude very premature births from analyses, the United States ranks very poorly. 

Even among people who accept the statistic, most assume that high infant mortality is because of poor prenatal care. But new evidence is coming to light that contradicts that conclusion. The problem appears to be focused on what happens after birth, not before. This new evidence could change our thinking on how to fix the problem.

Infant mortality is not distributed equally in the United States. In 2013, the infant mortality rate among non-Hispanic whites was 5 per 1,000 births, as was the infant mortality rate among Hispanics. The rate among non-Hispanic blacks, however, was more than 11 per 1,000 births. 

A number of other factors seem to play a role. Mothers younger than 20 years or older than 40 have children with a higher infant mortality. First babies have a higher chance of death than later siblings. Unmarried mothers also have a higher rate of death in their children. More than 70% higher than that of married mothers. 

The number one cause of infant mortality among newborns is premature birth. Which has traditionally been linked with inferior prenatal care. That may not be the case in the United States.

A 2006 study published in Epidemiology looked at how preterm delivery among women occurred among women in active-duty military installations. Such women received the same prenatal care regardless of race, or even socio-economic status. Because they were guaranteed care, their overall risk of premature delivery was low, just over 8%. But even among these women, black women were more than two times as likely as white women to deliver prematurely, regardless of military rank.

A Cochrane Systematic Review of the additional support women received during at-risk pregnancies included 17 studies and more than 12,000 women. Additional care was not associated with any improvements in any perinatal outcomes. C-sections were less common, as was hospital admission after birth, but infant mortality was not affected. 

Another such review examined how the number of prenatal visits affected infant mortality. Seven studies involved more than 60,000 women in countries of varying income. There was no difference in high-income countries in the number of deaths of those who had more or fewer visits. Although the number of deaths overall was low. 

In low- and middle-income countries, perinatal mortality was higher in groups with reduced visits but the overall difference was small. The authors concluded that in places where the number of visits was already low, reducing the number of visits further was a bad idea. This doesn't necessarily apply to standard care in the United States, though. 

A recently published paper in the American economic journal, Economic Policy, adds to this discussion. Alice Chen, Emily Oster, and Heidi Williams combined data from the United States with data from Finland, Austria, Belgium and Britain. The study adjusted for differences in coding of very premature births. And as other studies found before, the United States has a significant infant mortality disadvantage.

This study was different, however. It used microdata, or individual records of birth and death, as opposed to the aggregate data usually employed for cross-country comparisons. First, the researchers differentiated between neonatal mortality (death before one month of age) and post-neonatal mortality (death between 1 and 12 months of age).

The results showed that when it comes to neonatal mortality, the United States and other countries were pretty similar. If anything, the authors report, the United States might have a mortality advantage during this period.  Differences in post-neonatal mortality, or from one month to one year, however, were much more stark. In fact, they began to accelerate at one month of age. 

One explanation could be that this is just a delay in deaths. Perhaps the United States is just better at keeping these babies alive a little while longer than other countries are. Differences are seen all the way to one year though, making that unlikely.

The difference also doesn't appear to be because of race. A subanalysis that excluded African-American mothers from the sample still found a similar post-neonatal mortality disadvantage in the United States. Racial differences may be more applicable to neonatal mortality. 

Deaths in the post-neonatal period are due, in large part, to Sudden Infant Death Syndrome or SIDS, sudden death, and accidents. Moreover, they seem to occur disproportionally in poor women. It's not clear that healthcare is what would reduce deaths in this group. That doesn't mean that there's nothing we can do, it might even be cost-effective to try.

The authors of this paper estimated how much we might consider spending. They calculated that decreasing post-neonatal mortality to that of comparable European countries might lower the death rate by 1 in 1,000. Assuming a standard value of $7 million per life, it might make sense to spend $7,000 per infant. That might seem like a lot of money, but that's not out of the realm of what we spend on many other medical interventions. 

What exactly we might do with that money is up for debate. One suggestion made by the authors, with which I agree, is we consider programs of home nursing visits to reduce the incidents of SIDS an accidents. But some things do seem evident.

First, is that our constant calls for improved and more prenatal care may not significantly improve our disadvantage in infant mortality. The second is that spending a significant amount of money on poor women to improve the health of their 1-month to 1-year-olds might not only save lives; it might be cost-effective too. 

Healthcare Triage is supported, in part, by viewers like you through Patreon.com. A service that allows you to support the show through a monthly donation.

We'd especially like to thank our research associate Joe Sevits and our Surgeon Admiral Sam. Thanks, Joe! Thanks, Sam! 

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