One dozen infants weighing less than three pounds each were born at Columbia Hospital for Women in the past two months.

Less than seven years ago, the infants would have had less than a 1-in-8 chance of survival. Yesterday 11 of the 12 were still alive even though they each weighed about one third or less than the average full-term baby. According to Dr. John Scanlon. chief of the nurseries at Columbia, the one infant who died had severe birth defects and did not die because of low weight.

"I haven't got the faintest idea what the reason is" for the sudden large number of extremely premature births, Scanlon said. It is not unusual for some area hospitals with specialized nurseries to have up to five such babies under care at a given time. A dozen, however, is practically unheard of.

Columbia was so overburdened by the influx that Scanlon had to send one of the premature babies to Fairfax Hospital and two others to Georgetown University Hospital.

The influx of premature babies at Columbia comes at a time when the other intensive care nurseries in the Washington area are already at, or near, capacity.

Fairfax is full, the Children's Hospital National Medical Center is full, Georgetown has space for only two infants and the Washington Hospital Center has room for one.

"We have a woman in house at 30 weeks [a full-term pregnancy is 39 to 41 weeks] with triplets," Scanlon said late yesterday. "With these triplets coming up who will require an enormous amount of care-what am I going to do?"

Such infants also require an enormous amount of money to finance their care. According to area neonatologists - specialists in the care of infants from birth to 28 days - bills for the care of babies weighing under 21/2 pounds average $50,000.

According to Scanlon, 60 per cent of the babies cared for in the hospital's nursery last year were the children of poor women on Medicaid, which, he said, "pays zero to 30 per cent of the cost.

"It's not a question of alternatives, it's a question of priorities. Medicaid and health insurance can't turn a blind eye to this problem. We're going broke in our unit because we can't meet the costs of these things."

Even if Medicaid pays 30 per cent of the cost of care for the 11 babies. Columbia Hospital could be left absorbing up to $231,000 in charges for this one small group of patients.

At the same time, the babies will be in the unit for up to three months. occupying space that will not be available to babies born during that period.

"Where these babies ought to go, and where they will go," said Dr. Federick C. Battaglia, chairman of the department of pediatrics at the University of Colorado, "is into expanded perinatal facilities."

Battaglia, a nationally noted authority on the care of such infants, said that "the costs in the past dwarf these present costs. The literature in 1960 quoted over 60 per cent of the babies around (3 pounds) developing cerebral palsy. By the late 1960s it was down to around 10 per cent and now is almost extinct. Those things aren't taken into account when we talk about costs.

"I don't think these cases didn't occur in the past. They were just handled badly so you had mortality or 'mental or physical handicaps." Now we have these cases being sent to the special centers and the centers are swamped.

"Every intensive care unit is seeing a crush because the lay public is insisting on their obstetricians transferring them to the centers and because we didn't increase capacity. we're swamped. People are demanding the care before we build the facilities."

The demand for specialized care is one of the factors contributing to an "unprecedented baby boom" at Fairfax Hospital, said Dr. Lloyd Krammer, chief of the infant intensive care unit there.

"Selected hospitals have a good reputation now and they're getting swamped," said Kramer, who said the hospital will top all the records it set in the 1960s if it records the 5,000 births it expects this year.

"So far we haven't had to turn anybody away." he said, "but if it keeps on going like this I don't know that we're not going to get into trouble."

Such increased demand for limited space raises the spector of physicians having to decide which infants to treat and which to turn away for want of a bed. That, said Robert Veatch, author of "Death, Dying, and The Biological Revolution" is the wrong way to handle health care allocation questions.

"We're going to be in trouble if we try to make decisions of resource allocation with the hard cases in front of us, like 'what are we going to do with these triplets,'" said Veatch, an ethicist with the Institute for Society, Ethics and the Life Sciences, in Hastings-on-Hudson, New York.

"The more sound approach is to do our resource allocation at the level of policy, so the questions are answered far in advance and by a group different than the obstetricians and pediatricians negotiating over an individual baby . . . It's much harder to make the decisions when the baby'sin the intensive care unit."