The infant mortality rate in Alabama increased sharply last year - jumping to more than 9 deaths per 1,000 births for the first time since 2008.

Alabama's infant mortality rate is among the worst in the nation, and much higher than the national average of 5.8 in 2014. Only Mississippi had a higher rate of infant deaths in 2014, the most recent year available for comparison.

The death rate for African-American infants is more than two times higher than the rate for white infants, a stubborn trend that has persisted for the last several years.

In 2015, the Alabama infant mortality rate measured 8.3 deaths per 1,000 live births, according to the Alabama Department of Public Health.

"I would describe it as very worrisome and daunting," said Assistant State Health Officer Dr. Grace Thomas.

The leading causes of infant death in Alabama are congenital malformation, premature birth and Sudden Infant Death Syndrome. Preterm births before 37 weeks increased in 2016 to 12 percent of pregnancies.

Babies born prematurely often struggle with breathing and weight gain. All told, 537 babies died before they turned one in 2016, according to the Alabama Department of Public Health.

The reasons for the increase are complicated and difficult to identify, Thomas said. Factors including maternal health, access to prenatal care and social variables such as poverty can contribute to high rates of infant death.

Women in impoverished areas may face particular challenges, Thomas said.

"Our infant mortality rate is troubling and disheartening and trending in the wrong direction," said Dr. Scott Harris, acting state health officer for Alabama. "Challenges include ensuring mothers have access to healthcare before, during, and after pregnancy, reducing premature births, the opioid epidemic, and addressing persistent racial disparities."

Medicaid pays for almost half the births in Alabama, but coverage typically does not begin until a woman enrolls after becoming pregnant, which may take weeks or even months. Coverage through Medicaid typically ends a few weeks after birth.

Many rural hospitals have ended labor and delivery services in recent years, which may make it difficult for women in these areas to access care.

"I don't think there is one particular cause you can pinpoint," Thomas said. "It's multiple factors."