About 15 million premature babies are born every year — more than 1 in 10 of the world's births and a bigger problem than previously believed, according to the first country-by-country estimates of this obstetric epidemic.
The startling toll: 1.1 million of these fragile newborns die as a result, and even those who survive can suffer lifelong disabilities.
Most of the world's preemies are born in Africa and Asia, says the report released Wednesday.
It's a problem for the United States, too, where half a million babies are born too soon. That's about 1 in 8 U.S. births, a higher rate than in Europe, Canada, Australia or Japan — and even worse than rates in a number of less developed countries, too, the report found.
But the starkest difference between rich and poorer countries: survival.
"Being born too soon is an unrecognized killer," said Dr. Joy Lawn of Save the Children, who co-authored the report with the March of Dimes, World Health Organization and a coalition of international health experts.
Sophisticated and costly intensive care saves the majority of preterm babies in developed nations. The risk of death from prematurity is at least 12 times higher for an African newborn than for a European baby, the report found.
Globally, prematurity is not only the leading killer of newborns but the second-leading cause of death in children under 5. And no one knows how many suffer disabilities including cerebral palsy, blindness or learning disorders.
About 12 percent of U.S. births are preterm, about the same as estimates in Thailand, Turkey and Somalia. In contrast, just 5.9 percent of births in Japan and Sweden are premature.
Experts can't fully explain why. Part of the reason must be poorer access to prenatal care for uninsured U.S. women, especially minority mothers-to-be, said March of Dimes epidemiologist Christopher Howson. African-American women are nearly twice as likely as white women to receive late or no prenatal care, and they have higher rates of preterm birth as well, he said.
The report ranks the U.S. with a worse preterm birth rate than 58 of the 65 countries that best track the problem, including much of Latin America. Add dozens of poor countries where the counts are less certain, and the report estimates that 127 other nations may have lower rates.