Hawaii received a grade of “C” on the latest March of Dimes Premature Birth Report Card.

With the state falling short of an above-average grade for the past several years, Lin Joseph, director of program services for the March of Dimes Hawaii chapter, said, “We are disappointed that we didn’t see greater improvement.”

The national organization released its annual report based on 2014 data as part of November Prematurity Awareness Month. The overall national grade was also “C.” The U.S. preterm birth rate was 9.6 percent. In Hawaii it was 10 percent.

States that earned an “A” had premature birth rates less than or equal to 8.1 percent. States that earned a “B” were between 8.2 and 9.2 percent.

Premature birth is the leading cause of infant death. Babies born in less than 37 weeks are at a higher risk of developmental delays as well as breathing and vision problems.

Hawaii is among 18 states and the District of Columbia that received a “C.” Only Idaho, Oregon, Vermont and Washington earned an “A,” with 19 states receiving “B,” six receiving “D” and three (Alabama, Louisiana and Mississippi, plus Puerto Rico) receiving “F.”

In an effort to lower preterm birth rates, the local March of Dimes chapter is part of the Hawaii Maternal and Infant Health Collaborative, which also includes the state departments of Health and Human Services; Healthy Mothers, Healthy Babies Coalition of Hawaii; Hilopa‘a Family to Family Health Information Center; and hospital administrators and insurance providers.

The collaborative’s goal is to reduce the premature birth rate in Hawaii to 8 percent by 2018 by increasing access to prenatal care and encouraging women to wait at least 18 months between pregnancies to reduce risk, Joseph said.

Though there are factors that increase the risk — such as smoking and high blood pressure — women with no health-related concerns can also give birth prematurely, Joseph said. “We don’t know all the causes of preterm births.”

In addition to states, the report for the first time included grades for cities and counties with the highest number of births in 2013.

Portland, Ore., received the top “A” grade among the cities, with the lowest preterm birth rate of 7.2 percent. Shreveport, La., received the worst failing grade among the 100 cities with the highest number of births, with 18.8 percent.

Honolulu’s grade was a “C,” at 9.9 percent. Kauai County earned a “B” and both Hawaii and Maui counties received a “C.”

A breakdown of premature birth rates by race and ethnicity for each state is also included in the report. More information about the 2015 March of Dimes Premature Birth Report Card is available online at bit.ly/10FDWzF.