Preterm Birth Rates Drop in the US, but Still The Highest Industrialized Nation

The percentage of babies born early in the United States has reached a 15-year low and dropped for a sixth consecutive year, according to a new report.

Despite the progress, the March of Dimes' annual premature birth report card gave the nation a "C" grade. Meanwhile, six states -- Alaska, California, Maine, New Hampshire, Oregon and Vermont -- earned an "A" because their preterm birth rates met the group's 9.6 percent goal.

Preterm or premature births are considered when a baby is born before 37 weeks of gestation. Preterm birth is the leading cause of newborn death, as babies born between 34 and 36 weeks of pregnancy have triple the risk of death, compared with babies born between 39 and 40 weeks. Preterm babies also face serious and sometimes lifelong health issues, such as breathing problems, jaundice, developmental delays, vision loss and cerebral palsy.

"A premature birth costs businesses about 12 times as much as uncomplicated healthy birth," March of Dimes President Dr. Jennifer L. Howse said in a statement. "As a result, premature birth is a major driver of health insurance costs, not only for employers."

The US preterm birth rate remains the highest among industrialized countries, the report cautions. Preterm births cost the nation more than $26 billion annually, according to the Institute of Medicine.

The preterm birth rate peaked at 12.8 percent in 2006 after rising for more than two decades, according to the March of Dimes. The 2012 rate represents a 10 percent drop and the best rate since 1998.