TUESDAY, Nov. 17 (HealthDay News) -- The United States is doing a poor job of reducing preterm births, according to a new report, which found Mississippi, Alabama and Louisiana have especially high numbers of early, life-threatening deliveries.

Vermont and New Hampshire were the only states with a preterm birth rate under 10 percent, while in Louisiana, Alabama and Mississippi, the premature birth rate ranged from 16.5 to 18.3 percent.

Each year, the March of Dimes ranks each state according to its rate of premature births -- babies born before 37 weeks of gestation. Preterm births contribute to infant mortality and can put children at risk for lifelong problems, including cerebral palsy and developmental disabilities.

The U.S. premature birth rate was 12.7 percent in 2007 (the year the birth data was collected), nearly twice the goal of 7.6 percent set by the federal government's Healthy People 2010 campaign.

In the March of Dimes report, states were graded on how closely they came to meeting the preterm birth objective. No state earned an "'A" and Vermont was the only state to earn a "B" grade. All the rest earned grades ranging from "C" to "F" and the nation overall earned a "D" grade.

Still, it wasn't all bad news. Seven states -- Arizona, Indiana, Missouri, Idaho, Massachusetts, Utah and Wisconsin -- improved their grade year over year. However, Ohio's and Oklahoma's grades dropped.

"This year, we found a slight reduction in the rate of preterm birth," said Jennifer Howse, March of Dimes president. "Overall, that's encouraging. But as any good epidemiologist will tell you, one year does not a trend make."

Howse said she was concerned that the recession, including job losses and loss of medical benefits, could reverse the trend when the birth statistics from 2008 and 2009 are analyzed. "I think we're moving in the right direction, but I am worried we are going to see slippage," Howse said.

The states that improved did so by targeting three key risk factors for premature birth: smoking during pregnancy, lack of health insurance for pregnant women, and elective inductions or cesarean sections done during the "late pre-term," or between 34 to 36 weeks' gestation. The March of Dimes recommends babies not be delivered by elective C-section or induction before 39 weeks.

Lack of health insurance keeps some women from getting prenatal care, which means health conditions that could affect the pregnancy, such as underlying infections, obesity, poor nutrition, diabetes, high blood pressure and periodontal disease, are less likely to be caught and treated.

About 33 states and the District of Columbia reduced the number of women of childbearing age who smoke; 21 states and Washington, D.C. insured more women year over year; while 27 states, Washington, D.C. and Puerto Rico lowered the late pre-term birth rate.

Though the target areas are important, Howse said physicians still don't know all of the reasons why babies are born prematurely.

"We probably understand roughly half the risks that are associated with preterm birth, but the other half are very poorly understood from a biological standpoint," Howse said

Dr. Harold Perl, a senior neonatologist at Hackensack University Medical Center in Hackensack, N.J., said that physicians in the United States are very skilled at taking care of premature babies after they are born, but more emphasis needs to be placed on preventing premature births in the first place.

"Overall, it's a very important point that the March of Dimes is making," Perl said. "We have to look not only at how well we take care of our premature babies, but what we can do to prevent mothers from having premature babies."

The report didn't explore some significant geographic variations in causes for preterm birth factors that need to be considered when designing education or intervention programs, Perl said. New Jersey and Missouri, for example, had roughly the same rate of premature births, 12.7 percent and 12.5 respectively.

But in Missouri, about 28.4 percent of expectant mothers smoked, ranking it among the states with the highest maternal smoking rates, compared to 12.8 percent in New Jersey, ranking it among the lowest.

In New Jersey, a key reason for premature births is the number of twins, triplets and higher-order multiples being born as a result of in vitro fertilization procedures, Perl said. Twins are delivered on average, at about 35 weeks, triplets at 33 weeks, and quadruplets at 29 weeks, according to the American College of Obstetricians and Gynecologists.

Perl recommends fertility doctors follow American Society for Reproductive Medicine guidelines that call for implanting no more than two embryos at a time for women under 35, and no more than three for women with poorer chances of becoming pregnant.

About 540,000 babies are born prematurely in the United States each year, costing more than $26 billion in additional health care costs.

It's one of the reasons that the United States is ranked 30th in infant mortality, behind most other developed nations, according to a U.S. National Center for Health Statistics report issued earlier this month. Premature births have risen 36 percent since 1984, according to the report.

More information

The March of Dimes has more about preventing premature births.

SOURCES: Jennifer Howse, Ph.D., president, March of Dimes, White Plains, N.Y.; Harold Perl, M.D., senior neonatologist, Hackensack University Medical Center, Hackensack, N.J.; March of Dimes 2009 Premature Birth Report Card

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