For the first time in thirty years, premature births in the US has shown improvement, but the nation has a long way to go compared to other developed nations.
The study by the nonprofit March of Dimes group saw improvements in 32 US states and in the District of Columbia in percentage of pregnancies that continue for at least 37 weeks, with 40 weeks being full gestation for a newborn.
The group, which observes birth data over a two-year timeframe, reported a four-percent decline in premature births from 12.8 percent in 2006 to 12.3 percent in 2008.
Dr. Jennifer Howse, president of the March of Dimes, credited improved health policies for the change.
"The policy changes and programs to prevent preterm birth that our volunteers and staff have worked so hard to bring about are starting to pay off," said Howse.
"The two-year declines we have seen nationwide, though small, are encouraging," she said.
"We believe this decline is the beginning of a trend, but must be supported by better health care, new research and adoption of intervention programs to lower the risk of preterm birth."
Health officials said premature births are the leading cause of newborn death, and babies who survive early birth often face a lifetime of health challenges, including breathing problems, cerebral palsy, and intellectual disabilities.
Health officials said the last few weeks of pregnancy are particularly critical to a baby's development because the many important organs, including the brain, are developed during that time.
The US Institute of Medicine said that complications from preterm birth are a serious health problem that costs the United States more than 26 billion dollars each year.
Howse said that despite its declining premature birth rate, her group gave the United States a near-failing "D" grade, noting that there are stil1l more than half a million US infants born prematurely each year.
She also pointed out that most of the developed world fares far better in the percentage in the vital US health statistic.
"The United States has a high rate of preterm birth compared to top scoring states and, notably, most industrialized countries," said Howse.
US Surgeon General Regina Benjamin said in a statement accompanying the report that high preterm birthrate remains a serious problem that US officials must finally begin to tackle seriously.
"As a family doctor, I've seen the terrible impact of premature birth," the top US public health official said.
"It can cause life-long disabilities, and it is the leading cause of deaths in newborns," she said.
"Our country has one of the highest rates of preterm birth in the world, said Benjamin. "We have to do better."