Minnesota was one of only 17 states that failed to reduce its rate of preterm births in 2012, despite taking comprehensive steps to combat the problem.

The state’s rate of preterm births remained lower than the national average, but crept up from 9.9 percent of the total in 2011 to 10.2 percent last year.

The surprise result is contained in a report being released Friday by the March of Dimes on preterm births, those that take place before 37 weeks of gestation.

“When I saw this report, I was like, ‘aw, shoot!’ ” said Danielle Prenevost, communications director for the March of Dimes’ state chapter.

The rate of preterm births ticked upward even though Minnesota has successfully cut the number of pregnant women who smoke, the number of teens who have babies, and the number of doctors who induce labor too soon. The state has also increased the rate of pregnant women who have health insurance.

Health officials suspect the 2012 figure could prove a one-year setback in a decadelong run of improvement. But it shows the need for more work in preventing preterm births, which are strongly associated with birth defects, infant deaths and expensive hospital stays.

Health workers said it also underscores the growing need to focus on the overall health of pregnant women in the state, since they are increasingly likely to be overweight or have chronic health problems.

The number of births by women with chronic high blood pressure increased from 508 in 2006 to 688 in 2010, according to a Star Tribune review of federal birth statistics. Those women are twice as likely to give birth prematurely ­compared to others.

Many women who are obese, have diabetes or lupus also are at higher risk of giving birth early, said Dr. Lisa Saul, a high-risk pregnancy specialist at the Mother Baby Center in Minneapolis.

“Honestly, 20 years ago these women wouldn’t have been able to get pregnant and even consider having babies, but now they can” because of infertility treatments and other medical advances, she said.

It’s not clear, however, that the increase in pregnancies among women with serious health problems contributed to Minnesota’s increase in preterm births last year. The 2012 birth data in the March of Dimes report is still ­preliminary.

Other risk factors such as race, age and pregnancies involving twins or triplets are all associated with preterm birth risks, as well. And in four of 10 preterm births, the underlying cause is a mystery, ­Prenevost said.

Still, the health of mothers is key, she said. The March of Dimes has given $25,000 each to two Minneapolis community agencies this year to ­specifically improve the health of pregnant women by giving them information about diet, exercise and stress relief.

The first group of ­predominantly low-income women who participated have ­dramatically increased their purchases of fruits and vegetables. Most also have reported using stress-management techniques they learned in the Family Partnerships’ health ­decisions program.

Managing the stress of expectant mothers has emerged as a major challenge, said Princess Titus, co-founder of Appetite for Change, the other local agency supported by the March of Dimes.

“Most of these women are saying they are still at work or still caring for family members or caring for other children,” she said. “So their lifestyles haven’t changed but their ­bodies are changing. They’re caring for two people now.”

Convincing them to slow down means convincing them that they are not doing it just for their own well-being. “We ask them, ‘would you do it for your baby?’ ” Titus said.

Mira Vats-Fournier did a lot for her babies after learning that she would be at a high risk of preterm birth because she is diabetic and carrying twins. The Shoreview woman constantly monitored her blood sugar and kept regular appointments at the Mother Baby Center to make sure that she and her babies were healthy.

A vegetarian, she also increased the amount of ­protein she consumed — even though it revolted her husband when she ate peanut butter and salsa sandwiches. But she resisted other cravings.

“I craved salt a whole lot,” she said. “I have to admit it.”

Her twin girls, Kiran and Jaya, were born at 36 weeks on Monday. Everyone at the ­center wanted her pregnancy to last longer, Saul said, but the medical testing and prevention efforts resulted in a healthy mom and two healthy babies.

“Yeah, I kind of do a happy dance if 36 weeks is where we got and we had two healthy babies,” Saul said. “Sometimes that is the absolute best we can do.”