Last year, one of every eight babies born in the United States was premature, a number that is growing because of an increase the use of in vitro fertilization and other reproductive advances.
But the medical triumphs that allow a tiny 10-ounce baby to survive are often fraught with trauma and tragedy.
Consider this: At 25 weeks gestation or younger, a tiny baby can fit in the palm of a hand. Its skin is gelatinous -- red and shiny and prone to infection like a burn victim -- and sloughs off in the doctor's hand. The baby's windpipe is so small it can be crushed by a breathing tube.
And there is the pain, treated with narcotics that can cause dependency and withdrawal symptoms.
The long-term prognosis for babies this young includes mental retardation, blindness, deafness, cerebral palsy and — in the best scenario — learning disabilities.
Just Monday, Amillia Taylor — born at just 21 weeks and six days — suffered a setback after she was nearly ready to head home from Baptist Children's Hospital in Florida at a plump 4 pounds and 25 inches long.
Amillia is perhaps one of the world's smallest surviving babies -- although doctors say her age was determined by the day of conception (she was an IVF baby), rather than the conventional method of using the date of the mother's last menstrual period, making her actually two weeks older.
Still, even at 23 weeks of life, she is at a controversial crossroads, one week younger than the age at which a fetus can be legally aborted. Born just past the halfway point in a normal 37- to 40-week pregnancy, Amillia faces a likely struggle with health and learning problems.
"These babies survive, but they are extremely impaired," said Dr. Robert J. Boyle, professor of pediatrics at the University of Virginia's Center for Biomedical Ethics. "To do all of this for tiny babies takes a long time. From the time they are born until they go home, they go through a lot. How much do you subject a baby to, and what is the cost -- and I am not talking money -- in terms of discomfort."
In 2005, 12.5 percent of births in the United States were preterm or less than 37 weeks gestation, costing $26 billion a year, according to the National Institute of Medicine of the National Academies.
The number of babies born prematurely has dramatically increased in the last 20 years because of fertility treatments including IVF and fertility drugs like Clomid. The resulting infant death and long-term disability poses a serious public health issue, says the Institute.
A database run by the University of Iowa's Department of Pediatrics lists seven babies born at 23 weeks between 1994 and 2003, still a small number. Without extraordinary care, most of these babies die. But in the 25-week age group, about 50 percent survive.
"The incidence of these babies being born and entering the neonatal realm has increased; 20 to 30 years ago they never left the delivery room," said Dr. Boyle. "There are more of them overall now, and we take care of them."
Guidelines established by the American Academy of Pediatrics and the American Heart Association do not oblige a doctor to resuscitate an infant under the age of 22 weeks or one that weighs less than 400 grams -- or about a pound.
But with older babies "there needs to be an active discussion between parent and doctor," said Dr. Boyle.
Doctors who care for these babies find mixed reaction in parents. "We see both ends of the spectrum," said Dr. Boyle. "We live in a culture in which people believe in miracles and want to save a life, but there are other parents who don't want to take major risks have a child with a disability. For most, this is a sudden emergency and tragedy that they have never thought about before."
Such was the case with Sara Vassallie, a 26-year-old middle school teacher, who credits her doctors at St. Louis Children's Hospital with saving the lives of her twins born last November at 25 weeks gestation.
Experiencing pre-eclampsia that threatened to shut down her liver, Vassallie underwent a Caesarian section to deliver Hanna and Halie — each barely over a pound. The girls spent two months on a ventilator, and little Halie nearly died from an infection.
"Hanna made a little noise like a squeak when she came out," said Vassallie. "Their skin was see-through."
The family's bill for the babies' first 30 days of care -- excluding the doctor's bills -- was more than $700,000. Since January, the girls have been home breathing on their own and breast feeding. Hanna, now four pounds, has made it to a crib, but Halie, only three pounds, is still sleeping in an isolette.
"The doctors were really good talking to us about what to expect," Vassallie said. "They gave us the best and worst scenarios. From the very beginning we decided to do whatever was necessary. But it's been an ongoing process. There have been a lot of ups and downs like a roller coaster."
All babies born prematurely are at risk, but in those born before 25 weeks about half will have significant neurological problems like blindness, deafness, seizure or cerebral palsy.
A few -- about 25 percent develop mild symptoms like attention problems, stiffness in their legs and mild learning problems. Only about three percent to five percent have good cognitive and other functions, according to Dr. F. Sessions Cole, professor of pediatrics at Washington University School of Medicine, a neo-natal research center.
"But we can't tell in the delivery room which baby is in the top one-quarter," said Dr. Cole, a neo-natalogist who has treated more than 1,000 babies in 17 years.
The key to a premature baby's survival lies in its ability to breathe. All four chambers of the heart are pumping at 16 weeks, but the fetal lungs are not able to cope until much later, according to Dr. Cole. Even when the lungs are mature, they need to be able to "remodel" to adapt to the outside world.
"The machines are better than they used to be," said Dr. Cole. But ventilators can induce scarring and injury. "There are other risks when organs are not ready to be in the outside world: blood vessels in the brain bleeding and the intestines are not prepared to ingest breast milk or formula and there is a risk of infection from outside germs."
"There is no point when a premature baby is out of the woods and there are multiple medical problems that restrict and make acutely difficult their long-term survival," said Dr. Cole. "All these factors improve the later the baby is delivered."
In the case of Amillia Taylor, who was born with a mild brain hemorrhage, respiratory problems and digestive problems, she will need to be constantly monitored at home. But, she had a strong will to live, said her physician, Dr. William Smalling. "Her future looks bright at this point," he said.
But, Dr. Cole said, that often this is not the case, and families are often misinformed by friends or television programs. Families often don't want to hear about problems. Or what they have seen on television or heard from friends is often it is not transferable to their own baby's situation.
"They all want hope," said Dr. Cole. "The baby represents the future for parents, and that is a common theme. But most families have never experienced a premature birth. It is important for pediatricians to speak with the families and engage them in talking about their baby. My approach is we do everything we can for the baby, but if we get to the point where there is no chance for survival, or what we are doing is causing the baby pain."
Pain in these tiny infants is not as obvious as in older children, so doctors must look for clues: changes in their vital signs, heart rate or amount of oxygen in the blood stream, or grimacing or body movements.
"Parents want everything possible done for their baby," Dr. Cole said. "We let the baby be boss of this. If he comes out and he is vigorous and looks around and appears older, we go forward. Generally, we try to talk things over and air on the side of giving a baby a chance."
In the United States, the federal Baby Doe Law was passed in the 1980s to protect children with Down Syndrome and spina bifida. The law requires the doctor to try to save a baby unless it is "imminently dying or with most of its brain missing," according to Arthur Caplan, chairman of the department of medical ethics at University of Pennsylvania.
But, said Caplan, "At that time, it didn't apply to babies this small. There is a kind of ethical loophole here. The truth is, the law gives tremendous discretion to doctors, families and hospitals."
Other nations have policies on the treatment of premature babies. In The Netherlands, babies under the age of 26 weeks are not allowed to be resuscitated. Just last year, after two years of research, Britain's Nuffield Council on Bioethics issued recommendations on treating infants younger than 22 weeks.
"We don't think it is always right to put a baby through the stress and pain of invasive treatment if the baby is unlikely to get any better and death is inevitable," said professor Margaret Brazier, who chaired that ethics committee.
The British report gives guidance on how parents should resolve arguments with doctors over the fate of their babies. It rejects suggestions that active steps be taken to end life.
"Part of the problem is that despite advances in modern medicine, it is not always obvious to doctors, which babies will survive and thrive," she said. "Natural instincts are to try to save all babies, even if the baby's chances of survival are low."
This was not the case with Brian Dunlap, now a healthy 24-year-old snowboarder and New Hampshire dairy farmer who was one of the youngest babies ever saved at Denver Children's Hospital in 1983. Born 840 grams at about 26 weeks, he was given a 10 percent chance of surviving.
"He was right on the borderline," said his father, Bob Dunlap. "When he was born, they immediately asked us if we wanted a priest to give him the last rites. But as soon as he cried, we said, 'Heck, this kid doesn't look like he's dying.'"
Like other tiny newborns, Brian was given oxygen and intravenous feeding. His parents were warned that the oxygen he received could damage his retinas or burn his lung tissue, and he was monitored for months.
But today, Dunlap can laugh, even though there were some rough times.
"Brian is the only one in the family not to wear glasses, and he's never had respiration problems," Dunlap said. "Looking back, he didn't pay much attention in school, and that may have had something to do with his being a preemie. But he's doing what he wants to do, and that's always been his personality."