NEW YORK -- Tiny ''miracle babies" make for heartwarming stories, but the reality is that nearly half of all infants born extremely premature have significant learning and physical disabilities by the time they reach school age, the largest such study found.
Medical advances have allowed doctors to save earlier and smaller babies. While some developmental problems are known to be common among such children, the long-term consequences were not entirely clear.
''We needed to have some idea of really what this group was like when they grew up," said one of the researchers, Dr. Neil Marlow, a neonatologist at the University of Nottingham in England.
Guidelines call for not resuscitating the most severely premature babies, but where to draw the line is a controversial and emotional decision. The study's findings may help guide doctors and parents about whether it is wise to use heroic measures.
''Parents need to go into this situation with their eyes wide open and with an open dialogue with their doctors as to what they should do," Marlow said.
Normal pregnancy is 37 to 42 weeks. Marlow and his colleagues looked at 241 children about 6 years old who had been born between 22 and 25 weeks. They found that 46 percent had severe or moderate disabilities such as cerebral palsy, vision or hearing loss, and learning problems; 34 percent were mildly disabled; and 20 percent had no disabilities. Twelve percent had disabling cerebral palsy.
''This gives for the first time a real picture of what happens to these children who are at the limits of viability," said another researcher, Dieter Wolke of the University of Bristol in England.
Their findings are reported in today's New England Journal of Medicine.
The rate of premature births in the United States has crept up in recent years, in part because of a rise in multiple births and older mothers.
''It's important to realize that prematurity is a major public health problem. One in eight babies are born prematurely," said Dr. Scott Berns of the March of Dimes.
The British researchers tracked all extremely premature births in Britain and Ireland over a 10-month period in 1995. Of those who were born live, only a quarter survived and eventually went home from the hospital -- 1 percent of those born at 22 weeks; 11 percent at 23 weeks; 26 percent at 24 weeks; and 44 percent at 25 weeks.
The survivors were tested at 2.5 years, and about a quarter had severe disabilities. They were evaluated again at about 6 years.
Standard intelligence tests showed 21 percent of them had moderate or severe learning disabilities. That figure rose to 41 percent when compared to the test scores of a group of similar classmates who were born at full-term.
In an accompanying editorial, Drs. Betty Vohr of Women and Infants Hospital in Providence, and Marilee Allen of Johns Hopkins Hospital in Baltimore, said the study shows the limits of what medicine can do to help such babies.
''We wish they all were little miracle babies, but they're not," Vohr said.
Jamie Anderson of Logan, Utah, had to make a quick decision right before her twins were born at 23 weeks in 1997. She decided to have them resuscitated, although she knew the chances of survival were low and there was a risk of disabilities.
Her son, born at 1 pound 2 ounces, died within hours. Her daughter, Navy, who was 1 pound 6 ounces, endured four months of operations and blood transfusions before going home.
''We were fortunate to have one survive, but we know what it's like to lose one," said Anderson, who will be a March of Dimes ambassador this year.
As for her now 7-year-old daughter, Anderson said she is doing great with no complications and recently passed two milestones: learning to read and ride a two-wheel bike.