According to the Centers for Disease Control and Prevention, an almost decade long decline in infant-mortality rates has stalled and deaths directly linked to preterm births have increased, particularly for non-Hispanic black women. African-American babies stand twice more chances than white babies to die in their first year of life.

The study reveals a connection between infant death records and birth information. The oscillations in the U.S. infant mortality rate from 2004 to 2005 are few - 6.78 deaths per 1,000 live births vs. 6.86 deaths per 1,000 live births. Infant death rates were higher among boys than girls, said researchers.

Report’s findings show that overall death rates were lowest for Central and South American babies (4.68 per 1,000) and Pacific Islander or Asia babies (4.89 per 1,000) and highest for non-Hispanic black mothers (13.63 per 1,000.) Among Hispanics, infant mortality rates varied from 4.42 for mothers of Cuban origin to 8.30 for women of Puerto Rican ancestry.

Starting the mid-1980s, a stable rise in the number of preterm and low birth weight births has been noticed, the report disclosed. The reasons are said to be the increase in multiple births, partially the more frequent use of fertility methods and to the rising rate of women opting for C-sections, as well as labor induced before the 37th week of pregnancy.

"The differences in low birth weight and preterm births are major factors in the differences in infant mortality rates by race and ethnicity," the CDC report said.