(CNN) -- The United States is getting a "D" grade for its preterm birth rate, even though it is improving in most states, according to the March of Dimes.
The organization released its 2010 report card on Wednesday, the eighth annual Prematurity Awareness Day.
The March of Dimes compared the U.S. and each state with the target set in "Healthy People 2010." That report is issued every decade by the Office of Disease Prevention and Health Promotion and the U.S. Department of Health and Human Services. The target rate for preterm births is 7.6 percent or less. There are currently no states that meet that. The current nationwide rate based on the report card is 12.3 percent.
"The reason for the 'D' is that more than half a million babies are born premature in the United States," says Jennifer Howse, the president of the March of Dimes Foundation. And premature birth is the leading cause of newborn death and many disabilities, including breathing problems, cerebral palsy, and intellectual disabilities, according to the March of Dimes.
"The United States has one of the highest rates of preterm births of industrialized countries in the world, " says Howse. The U.S. surgeon general also unveiled a new PSA on Wednesday, with similar findings.
Even with the "D" grade, there may be reason to be optimistic about the preterm birth rate: Following three decades of increases, there have been two years of decreases at a rate of 4 percent, according to Howse. That means 21,000 fewer babies were born preterm. Forty states and the District of Columbia have improved their preterm birth rates. And eight states improved their grade altogether.
"The good news is that we are getting better," says Dr. Hal Lawrence of the American College of Obstetricians and Gynecologists. He explains some people might choose to deliver preterm: "It can be by patient request or for the timing of delivery for both physician and patient. And, sometimes it's merely for convenience, or so they don't travel too far while in labor."
"States can help lower their rates of premature birth by ensuring that pregnant women have health insurance coverage and by supporting programs that help moms quit smoking during pregnancy," says Howse. She explains, women should not be induced or have an elected cesarean section before 39 weeks, unless there are medical reasons.
"The consecutive two-year drop suggests a downward trend in premature births, " says Carol Hogue of the Rollins School of Public Health for Emory University. But, she points out the percentage of uninsured women is going up, and that concerns her.
Hogue also thinks that a way to help reduce the rate of preterm births is in spacing.
"The ideal space between pregnancies is 18-23 months. If it is six months or less there is a 40 percent increase in preterm birth," Hogue said.
Howse also points to intervention programs that she says work.
They combine consumer awareness and education, screenings and referrals for women for treatable and preventable conditions, prenatal care and appropriate care between pregnancies; and professional education.
The March of Dimes says it will issue a report card every year until the target is met.