TUESDAY, July 19 (HealthDay News) — Infants weighing less than 2.2 pounds at birth are now much more likely to survive thanks to medical advances, but their survival often comes at a price, a new study finds.

These infants, technically termed extremely low-birth-weight, are at greatly increased risk of experiencing chronic health conditions as well as educational and functional limitations, compared to babies born at normal weight.

Researchers report that these health problems can persist to elementary school age, at least.

“I think none of us were surprised at the finding,” said Dr. Deanne Wilson-Costello, a co-author of the study and co-director of the neonatal high risk follow-up at Case Western Reserve University and Rainbow Babies and Children’s Hospital, Cleveland. But it was sobering that the problems were still present at school age, she added. “Our hope was they would have the problems [only] as a small child.”

The study appears in the July 20 issue of the Journal of the American Medical Association.

In the study, Wilson-Costello and a team led by Dr. Maureen Hack evaluated 219 extremely low-birth-weight children and 176 normal-birth-weight children, born from 1992 to 1995. They tracked their development for eight years, trying to determine if the low-birth-weight kids encountered special health, education or other needs.

Taking sociodemographic status and other factors into account, the researchers found the low-birth-weight children had many more chronic conditions than normal-weight children. For example, 64 percent of underweight babies experienced functional limitations — difficulties with eating, mental or emotional delays or difficulties dressing. In contrast, just 20 percent of normal-weight children faced these types of problems.

While none of the normal-weight children had cerebral palsy, 14 percent of low-birth-weight children did. Asthma, vision of less than 20/200, IQ less than 85, poor motor skills and limited academic skills were also more common among low-birth-weight than normal-birth-weight children.

About half of the low-birth-weight children, but just 23 percent of kids in the normal-weight group, had what experts call “compensatory dependency needs” related to a chronic condition lasting 12 months or longer. This meant that they required prescription medication regularly or needed special equipment to walk or feed themselves.

While 65 percent of the low-birth-weight children required services above those routinely needed for their age, just 27 percent of the normal-weight children did.

The authors believe their report is the first to describe school-age outcomes of extremely low-birth-weight children born in the United States in the 1990s.

Despite this sobering news, Wilson-Costello said there is reason to hope that the picture will become brighter with each year, as medical advances make not only the survival of these tiny newborns possible, but also improve their quality of life later on.

For instance, she said, the “cavalier” use of postnatal corticosteroid medications — used to help wean babies off ventilators — has “fallen out of favor,” she said.

According to Wilson-Costello, one side effect of postnatal steroid use is impaired cognitive function and inhibited brain growth. So their use is considered much more carefully nowadays, she said.

Despite medical advances, Wilson-Costello said “it’s still easier to keep low-birth-weight babies alive than to prevent low birth weights.”

To reduce the risk of giving birth to a low-birth-weight infant, she said, “getting good prenatal care is essential.” But as Wilson-Costello knows all too well, early monitoring isn’t foolproof — she gave birth to her first child, a 1.5-pound baby girl, last October.

Pre-birth ultrasound might help detect pro