HOLLANDALE, Miss. — For decades, Mississippi and neighboring states with large black populations and expanses of enduring poverty made steady progress in reducing infant death. But, in what health experts call an ominous portent, progress has stalled and in recent years the death rate has risen in Mississippi and several other states.

The setbacks have raised questions about the impact of cuts in welfare and Medicaid and of poor access to doctors, and, many doctors say, the growing epidemics of obesity, diabetes and hypertension among potential mothers, some of whom tip the scales here at 300 to 400 pounds.

“I don’t think the rise is a fluke, and it’s a disturbing trend, not only in Mississippi but throughout the Southeast,” said Dr. Christina Glick, a neonatologist in Jackson, Miss., and past president of the National Perinatal Association.

To the shock of Mississippi officials, who in 2004 had seen the infant mortality rate — defined as deaths by the age of 1 year per thousand live births — fall to 9.7, the rate jumped sharply in 2005, to 11.4. The national average in 2003, the last year for which data have been compiled, was 6.9. Smaller rises also occurred in 2005 in Alabama, North Carolina and Tennessee. Louisiana and South Carolina saw rises in 2004 and have not yet reported on 2005.