High rates of premature birth are the main reason the United States has higher infant mortality than do many other rich countries, government researchers reported Tuesday in their first detailed analysis of a longstanding problem.
In Sweden, for instance, only 6.3 percent of births were premature, compared with 12.4 percent in the United States in 2005 — the latest year for which international rankings are available.
Infant mortality also differed markedly: for every 1,000 births in the United States, 6.9 infants died before they turned 1, compared with only 2.4 in Sweden. Twenty-nine other countries also had lower rates.
If America could match Sweden’s prematurity rate, the new report said, “nearly 8,000 infant deaths would be averted each year, and the U.S. infant mortality rate would be one-third lower.”
Dr. Alan R. Fleischman, medical director of the March of Dimes, said the new report was “an indictment of the U.S. health care system” and the poor job it had done in taking care of women and children.
Infant mortality is widely used as a way to gauge the health of a nation, and the relatively high rates in the United States have long dismayed health officials.
The high rates of prematurity in the United States have various causes. The smallest, earliest and most fragile babies are often born to poor and minority women who lack health care and social support. The highest rates of infant mortality occur in non-Hispanic black, American Indian, Alaska Native and Puerto Rican women.
When it comes to prematurity, fertility treatments — drugs that stimulate ovulation, and procedures that implant more than one embryo in the uterus — also play a role, by raising the odds of twins or higher multiples, which have an increased risk of being born too soon.
Another factor is the increasing use of Caesarean sections and labor-inducing drugs to deliver babies early, said Marian F. MacDorman, a statistician at the National Center for Health Statistics and an author of the report.“I don’t think there are doctors doing preterm Caesarean sections or inductions without some indications, but there sort of has been this shift in the culture,” Dr. MacDorman said. “Fifteen or 20 years ago, if a woman had high blood pressure or diabetes, she would be put in the hospital and they would try to wait it out. It was called expectant management. Now I think there’s more of a tendency to take the baby out early if there’s any question at all.”