In 2009, advocates working to reduce child mortality rates around the globe had cause to celebrate. The year marked the first time the number of children who died before the age of five dipped below nine million, according to UNICEF data.

Strategies aimed at improving the children’s chances to survive are working, but the United States can’t quite join in on the celebration.

According to the World Bank, the U.S. has the highest infant mortality rate among 33 countries that the International Monetary Fund defines as having “advanced economies.”

In 2006, the U.S. infant mortality rate was 6.71 deaths per 1,000 children. According to research estimates, that’s about the same rate as last year. On a broader global scale, the nation lags behind countries like Cuba and Chile. The U.S. ranks 42nd in the world in child mortality, according to a study by the Institute of Health Metrics and Evaluation at the University of Washington, published in the medical journal The Lancet last May.

For those who study child mortality, the fact that the U.S. fares worse than other developed nations is no surprise. But what shocks even researchers is that the country isn’t keeping up with global gains in reducing child mortality, despite significant health care spending.

“What is surprising is that the U.S. continues to fall even farther behind, while other developed countries such as Australia and New Zealand have shown much better improvements in child mortality,” Julie Rajaratnam, assistant professor with IHME and one of the study’s authors, wrote in an email to DOTmed News. “If we look at progress over time, we see the U.S. was ranked 29th in the world in 1990 and has dropped to 42nd now,” she said. “What that tells us is that we’re not making as much progress as other high income countries.”

And the study shows it’s not only the top industrialized economies leaving America in the dust. In 1990, Serbia and Malaysia had higher child mortality rates than the U.S., but by 2010, both countries managed to reduce their child mortality rates by 70 percent, while the U.S. only saw a 42 percent decline, in pace with Kazakhstan and Sierra Leone. Even Singapore, which has the world’s lowest child mortality rate of 2.5, slashed its rate by two-thirds between 1990 and 2010.

To make matters more complicated, it’s important to recognize that the rankings aren’t all black and white. International differences in data collection might unfairly impact America’s standing.

For instance, the definition of a “live birth” varies by country, points out Dr. Kimberly Gregory, vice chair of women’s health care quality and performance improvement at the OB/GYN department of Cedars-Sinai Medical Center, and professor at the David Geffen School of Medicine at the University of California, Los Angeles. Thus, we’re not always “comparing apples to apples,” says Gregory, who is also a member of the Society for Maternal-Fetal Medicine.

“But having said that, [our infant mortality rate] is embarrassing for us, given how affluent we are as a country. It would certainly be great to see us doing better,” she says.

So what accounts for America’s high IMR when compared to other industrialized nations? Contributing factors often intertwine, making it difficult to pinpoint problems, but the major issues are known, and fortunately, so are some strategies for improvement.

Before the due date
The leading causes of infant death in America are congenital defects, preterm birth and low birth weight and sudden infant death syndrome.

According to a 2009 report by the National Center for Health Statistics, compared to Europe, America has a higher percentage of preterm births, likely the main cause of its higher IMR. (Preterm is defined as birth before 37 completed weeks of gestation.)

According to the study, in 2005, in Sweden, 6.3 percent of babies were born prematurely, while 12.4 percent were born early in America. Per 1,000 births, the U.S. lost 6.9 infants before their first birthdays, while Sweden lost 2.4. If America could match Sweden’s prematurity rate, “nearly 8,000 infant deaths would be averted each year and the U.S. infant mortality rate would be one-third lower,” the study’s authors wrote.

About one in eight babies in the U.S. is born prematurely, a total of more than 500,000 babies a year, says Dr. Scott Berns, a pediatrician and a senior vice president with the March of Dimes Foundation.

Premature babies are at risk for a slew of health and developmental problems. In 2005, 68.6 percent of all infant deaths “occurred to preterm infants,” according to a NCHS data brief on U.S. trends in infant mortality.

But reducing preterm births is a complicated matter, as the baby’s arrival before the due date can have many causes.

Around 25 percent of the time, the baby’s premature birth can be explained, according to Berns. Maternal distress or a sign of fetal distress often require an early delivery for medical reasons. But then there are times when the baby comes early for reasons that are unknown. “About half the time, there’s no specific risk factor or cause. A woman can do everything right and still have a baby born prematurely,” says Berns.

Why us?
It’s well known that women who smoke, are obese, suffer from chronic medical conditions or have certain uterine problems are at a higher risk of having a premature baby. But if European countries and the U.S. are on par in understanding contributing risk factors, why are more babies born prematurely in the U.S.?

What we do know is that American women tend to have babies at a more advanced age, which heightens the risk for early delivery. American parents also commonly employ the aid of fertility treatments. The number of women who used assistive reproductive technologies doubled from 1996 to 2002, according to a 2006 Institute of Medicine report. Researchers found at least half of the women who used ART became pregnant with two or more babies, and multiple births are a high risk for preterm delivery.

Many experts also draw links between America’s vast socioeconomic disparities and infant death. While both preterm birth and SIDS can happen to any family, these conditions are more prevalent among poorer Americans. (According to Gregory, half of U.S. births are funded by Medicaid.)

There are also significant differences in IMRs by race and ethnicity. A 2008 NCHS report found that the infant mortality rate for black women was 2.4 times the rate for white women in 2005.

The report’s authors reasoned that high risk factors such as socioeconomic status and access to medical care in part play a role in explaining the variance in the rates but “many of the racial and ethnic differences in infant mortality remain unexplained.”

Elective delivery
Additional factors that distinguish the delivery of American infants from those in other developed nations are caesarean sections and drug inductions for early deliveries.

The American College of Obstetricians and Gynecologists maintains that unless there is a medical reason for doing so, babies should not be delivered before 39 weeks. And yet, the U.S. rate of early deliveries is higher than in other countries, and “medical justification for a significant proportion of early deliveries is questionable,” according to a 2010 March of Dimes report.

According to the report, 10 to 15 percent of births in the U.S. are elective deliveries that are carried out without medical indications and before 39 weeks. Elective delivery before 39 weeks is “associated at a minimum with significant short-term morbidity,” the report says.

Babies who are delivered early are also more likely to end up in intensive care units. And studies show that infants born before 39 completed weeks have higher rates of respiratory distress syndrome and infant death.

“The bottom line is babies should be born at the right time, for the right reason,” says Berns. “It shouldn’t be done for the convenience of moms, the family or a provider because it works out with his or her schedule.”

“The womb is the best place for the baby,” he adds.

What can be done?
Although the societal factors that may influence infant death rates are many, it doesn’t mean America can’t take steps to improve newborn survival rates.

For one, a simple strategy that should be ongoing is patient education and awareness. For example, many women will show up to the hospital with preterm contractions, only to be sent home and reassured that it’s not time yet. When a woman experiences the contractions again, she may be too embarrassed to come back. But women should be mindful of preterm contractions and “seek medical attention sooner and repetitively,” says Gregory.

When it comes to elective, non-medically indicated deliveries, March of Dimes recommends establishing quality improvement programs and facility-based protocols that would reduce or eliminate birth before 39 completed weeks of gestation.

The frequency of delivery before 39 but after 37 weeks may have created a “false sense of security,” says Gregory. Because physicians often tell women it’s OK to go into labor after 37 weeks, many have internalized it to be a safe number of weeks in the womb.

Thus, many physicians and patients have a hard time accepting that there is a true difference between a baby born at 37 and 39 weeks. “And that’s due to what you see every day,” explains Gregory. “If you delivered 100 babies at 37 weeks and they all came out perfect, it’s hard to believe it’s a problem. But in order to see the problem, you have to see maybe 1,000 or 2,000 babies. You need a bigger denominator to understand the implications of the problem,” she says.

Cedars-Sinai is in agreement with March of Dimes’ advice. At the facility, a birth prior to 39 weeks must be accompanied by a documented reason for the delivery. “A lot of hospitals are [carrying out] very active campaigns to educate both patients and doctors,” Gregory says.

Continuous research
Providers are also optimistic about evolving research around interventions that may reduce preterm births or provide better protection for vulnerable infants.

In early April, the National Institutes of Health shared the promising findings about progesterone, a naturally produced hormone. It was shown to reduce the rate of preterm birth before 33 weeks by 45 percent among women with short cervixes, a characteristic known to heighten the risk for premature delivery.

There is also ongoing research around the impact of magnesium sulfate on protecting a premature baby’s brain. “Learning how to use that judiciously may also help decrease the incidence of death after preterm birth,” says Gregory. “That’s something that’s evolving right now.”

Improvements in neonatal intensive care units and better access to health insurance and prenatal care among high-risk populations can all contribute to improved outcomes.

To ensure the research around infant death and preterm birth continues to uncover new trends and effective strategies, March of Dimes is pushing for the support of entities such as NIH and the National Institute of Child Health and Human Development on the policy front.

“What we’re really focusing on now is trying to advocate for key programs that we want to make sure continue to get the funding they deserve to address [preterm birth] issues,” says Berns.

Perhaps one of the most difficult aspects of improving infant death rates in the U.S. is rooted in understanding the effects of the country’s disparities. According to IHME’s Rajaratnam, looking at the U.S. child mortality rates by counties would likely identify areas that are performing just as well as Europe, and others on par with the world’s poorest countries.

To find the answer to the question of why we’re so slow in improving the health of our babies, researchers are looking to explore trends in child and infant death region by region. “We are starting to do some of that local level research now and those results will help us get closer to putting our finger on what needs to change in order to save more lives,” Rajaratnam said.