What's causing the increased death rate among babies in the United States?
While the health of infants in many countries is improving, babies born in the United States now face an increased risk of dying in the first year of life.
The U.S. infant mortality rate is on the rise for the first time since 1958, according to the Centers for Disease Control and Prevention. In 2001, the infant mortality rate was 6.8 deaths per 1,000 live births -- in 2002, the rate rose to 7.0. (2003 data is not yet complete.)
At the same time, other countries are improving their infant mortality rates to the point that they have surpassed the United States. Cuba, for example, reported a lower 2002 rate than the United States at 6.3.
The CIA World Factbook estimates the infant mortality rate in the United States is now comparable to Croatia, Lithuania and Taiwan. Most analysts currently rank the United States 28th in the world in infant mortality, far behind other industrialized nations such as Sweden, France, Japan and Germany.
According to health care experts, there is no simple explanation for the increase in U.S. infant mortality.
"But there are a number of factors that could contribute," said Dr. William A. Engle, neonatologist with the Indiana University School of Medicine in Indianapolis.
"The number of babies born pre-term has increased in general, and pre-term populations are at a higher risk for morbidity and mortality," Engle said.
Births of two or more babies are often associated with prematurity, and, Engle said, "the number of multiple births has increased." Some of these multiple births are the result of fertility drugs and in-vitro fertilization procedures.
Engle explained that while a normal, healthy gestation period is 40 weeks, because of the increased number of pre-term deliveries, the gestation period in the United States now averages just 39 weeks. "The 34- to 37-week gestation group has increased over the last 10 years," he said. "There are fewer births after 40 weeks than there were even a few years ago."
Within the United States, there are important differences in the infant mortality rates between racial groups and across geographic boundaries.
"Infant mortality rates tends to trend with socio-economic status," said Dr. Nancy Green, medical director for the March of Dimes. "African-Americans have much, much higher rates of infant mortality than other groups."
The rate among African-Americans is nearly double that of the general population: 13.9 versus 7.0. Rates among some other ethnic minorities also tend to be higher: the infant mortality rate among Puerto Ricans is 8.2, and for Native Americans, the rate is 9.1.
"Some of that is due to poverty but it doesn't track perfectly with poverty," said Green. The infant mortality rate among Central and South American immigrants, for example, is only 5.1.
Infant mortality rates also vary from state to state. "The states in the Southeast tend to have higher infant mortality rates than others," said Green. Most of the Southeast has rates exceeding 7.5, while most West Coast and Northeast states have rates below 6.2.
Part of the reason U.S. infant mortality is rising in comparison to other countries is because while the U.S. rate has remained fairly stable, many other countries have greatly improved their health care systems.
"There has been a huge shift in infant mortality rates in what we call 'middle-income countries,'" said Christopher P. Howson, vice-president for global programs for the March of Dimes, referring to nation like Cuba and the Czech Republic.
Howson attributes much of this improvement to enhanced vaccination programs, improved nutrition and public hygiene, and a safer environment for families.
"We should look at these countries for lessons that we can learn and apply back in our country," said Howson.