The smallest premature babies, already at high risk of brain damage, are likely to develop even more mental disorders if they get any infection in the first weeks of life, researchers said on Tuesday.

The babies, a majority of whom contract an infection, face increased chances of brain injury and ailments such as cerebral palsy, according to a study by the U.S. government’s National Institute of Child Health and Human Development.

“This study shows us that successfully treating an extremely low birth weight infant’s infection does not automatically ensure that the infant will do well,” said Duane Alexander, director of the institute.

“Parents and health care workers need to monitor these children carefully as they grow, and be ready to provide them with developmental and educational services,” Alexander added.

The research at Emory University School of Medicine in Atlanta, published in this week’s Journal of the American Medical Association, found that 65 percent of more than 6,000 extremely low birth weight infants developed at least one infection in the first 120 days of life.

When examined at 18 and 22 months, those infants were more likely to have an impairment such as cerebral palsy, lower mental development, psychomotor problems and vision troubles than others who did not get an infection, the study said. The problems occurred regardless of the type of infection or where it was in the body.

Extremely low birth weight babies weigh from 14.2 to 35.3 ounces (402 to 1,000 grams) at birth. In general they run a high risk of short-term illness and death, as well as developmental problems later in life.

“Possible interventions to reduce brain injury associated with infection might include earlier diagnosis and improved therapies,” the study said. “Ultimately, efforts to reduce the high rates of infection in (such) infants are the most important interventions.”

SOURCE: Journal of the American Medical Association, November 17, 2004.