It’s no secret that the US—when compared to similarly well-off countries—is not that great at keeping its infants (and new moms) alive. But a new study published Tuesday in PLOS-Medicine offers a detailed state-by-state look of how short of the mark we’re falling: Infants born in the US can be over twice as likely to die before their first birthday than in stable European countries. And the new work also seems to rebut a common theory for why these deaths are happening.
Because more women in the US deliver their children prematurely than elsewhere, earlier studies have suggested this could largely explain the mortality gap. But when the researchers of this current study compared rates of infant mortality across the US from 2010 to 2012 to six European countries where rates have been historically low, that’s not what they saw.
“Surprisingly, we found that the US actually performs comparably to other high-income countries when it comes to the survival of preterm infants,” lead author Neha Bairoliya, a researcher at the Harvard Center for Population and Development Studies, told Gizmodo via email. “The same is not true for infants born full-term, where children born in the US face more than twice the mortality risk of children in leading European countries.”
Specifically, full-term infants in the US were anywhere from 50 percent to 200 percent more likely to die within the first year of life than infants in Austria, Denmark, Finland, Norway, Sweden, and Switzerland, depending on the state. Some of the best performing were coastal states such as New York, California, and Massachusetts, while the worst states were concentrated in the Southern and Central US, such as Ohio, Kentucky, and Georgia.
The major drivers of infant deaths were two-fold, Bairoliya and her co-author found. There were children who died from birth defects, and children who suddenly and unexpectedly died, oftentimes from Sudden Infant Death Syndrome, or SIDS. Sudden, unexpected deaths accounted for 43 percent of all infant deaths during the study period, the largest slice of any cause, while birth defects accounted for 31 percent.
Deaths caused by birth defects are difficult to predict or actively prevent, Bairoliya says, although better access to prenatal screening and family planning services could catch these defects earlier. But while there’s still a lot we don’t understand about SIDS, the findings do suggest there are meaningful things we can do to reduce these deaths as well as those caused by accidental suffocation.
Children sleeping on their bellies or sides are more likely to die of SIDS and suffocation. And sleeping on very soft beds, in hot rooms, or with their parents are also risk factors. “Given the high mortality burden due to SIDS and suffocation, policy efforts to promote compliance with recommended sleeping arrangements could be an effective first step in this direction,” Bairoliya said.
The findings also provide an important reminder about the hardships mothers living in some states are more likely to face.
“Full-term deaths due to SIDS, suffocation, maltreatment, neglect, or violence are four times higher in Mississippi as compared to Connecticut,” Bairoliya noted. “When comparing across US states, we do find that low education of mothers, poor health, and other risk factors can explain part of these mortality differences.”
It’s estimated that over 7,000 infants die annually in the US every year. And according to the CDC, there were 5.9 infant deaths per 1,000 live births in 2015. The authors estimated that 4,000 infant deaths a year may have been prevented if all 50 states lowered their rate to match the best performing state in each major category of the cause of death.
However, it’s likely these numbers have improved overall since 2012, thanks largely to the Affordable Care Act, which expanded Medicaid eligibility in several, often poorer, states. Past studies of pregnant women in the 1990’s have shown a similar pattern of reduced infant deaths following Medicaid eligibility, Bairoliya notes. She and her colleagues are already in the middle of a project that will study more recent years.
“We would also like to get a better understanding of how much of the differences in mortality risks among full-term infants, both across US states and between US and Europe, can be explained by differences in risk factors like low household incomes or differential [prenatal] care standards as well as differential access to health services,” she said.