It's a little life fraught with danger, for pre-mature babies who are born extremely small. Christened micro-preemies, as they weigh less than 1000 grams, they fall well below the lower limit for extremely tiny babies.
Doctors who care for these low-weight babies caution that surviving long enough to go home, after months in a neonatal intensive care unit, is not usually the end of their struggle. Though advances in medical technology have improved their chances of survival, the percentage with major complications, such as blindness, deafness and cerebral palsy, has not changed.
Says neonatologist Jonathan Muraskas of Loyola University Medical Center, Illinois: "It's one thing to survive, but another to live a life blind and deaf and in a wheelchair."
Incidentally, the chance of surviving without a major handicap depends on the length of gestation, and not on birth weight. At 23 weeks, the chance of survival could be termed- "maybe" 20 percent, while the risk of a major handicap is nearly 90 percent, according to Muraskas.
The outlook for babies born at 25 weeks is far brighter. Of them, 75 percent survive, with only 10 percent of them suffering a major handicap. Yet, about half will have a mild handicap, such as a learning disability, often not apparent until they're in school.
"These kids do tend to be smaller than their peers, especially skinny, but most of them are functioning in regular classrooms, and the families are glad to have them," says University of Iowa pediatrician Edward Bell. He created a registry of the "tiniest babies" after the parents of his smallest patient asked whether he knew of any others that size.
Some facts remain, like: survivors are more likely to be girls than boys, and they are all born small for gestational age, often because their mothers had pregnancy-associated high blood pressure. A normal-size fetus at just 20 weeks' gestation weighs 11 ounces, at which point the organs would be too immature for survival outside the womb.
Another fact remains that doctors can never predict which tiny babies will do well and which will not.
Says neonatologist Siva Subramanian of Georgetown University Hospital in Washington, D.C.:"I think we really should counsel the parents more carefully and not highlight the miracle stories, but give a clear picture of what is the evidence in terms of survival."
Most neonatologists believe babies born before 23 weeks' gestation have virtually no chance of surviving, no matter how aggressively they're treated.
Agrees William Caplan, a neonatologist at Memorial Hermann Southwest Hospital. Most of his colleagues tell parents of babies born 24 weeks or younger, that though they will strive to send the baby home, there could be 'big-time complications'. "We are presented with a little baby at delivery, and we really have no idea what they're going to be like in the next month or in the next 30 years, frankly', states Caplan.