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Age Of Fetal Viability Lowered by Full Month Since Roe vs. Wade

April 22, 1989 GMT

WASHINGTON (AP) _ In 1973, when the Supreme Court issued the Roe vs. Wade decision that legalized abortion, the fate of babies born more than two months premature was simple.

They died. Almost invariably.

In the 16 years since that court decision, advances in treatment have lowered the age of viability for premature infants by a full month.

Human beings who at birth are smaller than a person’s palm and weigh just over a pound now are nurtured by an arsenal of equipment, drugs and skills that didn’t exist in 1973.

Now, babies born in major hospitals after only 24 weeks of gestation have a fighting chance to survive, flourish and go home.

Thus, if certain conditions are met, some abortions still may be performed on fetuses with a potential for viability outside the womb, forcing hospitals, clinics and doctors to make rending decisions that touch the very heart of the abortion controversy.

Maureen C. Edwards, a physician who specializes in treating premature babies at George Washington University Hospital, believes that in many cases the lines have ″merged.″

″The therapeutic abortions are being performed within a range that we might have a viable baby,″ said Dr. Edwards. Such abortions usually follow prenatal tests, such as amniocentesis, that detect some genetic abnormality in the infant, she said. But some abortions at the edge of the second trimester are performed for the convenience of the mother.

″There are places that will terminate at 23 or 24 weeks,″ said Dr. Edwards. ″It is part of the problem.″

The Supreme Court is hearing arguments Wednesday on a Missouri case in which the justices are being asked to overturn or substantially limit the landmark Roe vs. Wade decision legalizing abortion. Among the issues before the court is a regulation that requires doctors in some cases to determine whether the fetus is viable. If such a determination is made, the regulation says, the doctor must perform the abortion in a way best designed to preserve fetal life.

An infant brought into the world after only 24 weeks of gestation faces an awesome struggle to survive. There’s not a single organ in the baby’s body that is yet ready to live unaided outside the womb. The lungs, heart, brain, liver and digestive system all are only partially formed. All of the blood in the body of such a baby equals only about three tablespoons.

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The lungs are usually the organs most threatened by early birth. In many cases, the air sacs have yet to develop the blood vessels needed for the body to absorb oxygen from inhaled air.

A critical substance, surfactant, is also missing. This sudsy protein, which a fetus usually develops in about the 30th week, keeps the lungs from collapsing between breaths. Its absence often leads to respiratory distress and death.

In many cases, a premature infant’s brain is not yet ready to support life and is unable to control breathing and other automatic body processes.

Often, the preemies’ heart valves and vessels are still unfinished and not functioning well.

And, almost invariably, the babies are unable to take food by mouth, a factor that for decades meant death.

″The rule was, if they can’t take food by gut, then they died,″ recalled Dr. Edwards.

In 1973, size alone could determine fate. Premature infants were micro- creatures in a macro-world of medicine that was unable to cope with miniscule needs.

Needles were too large for veins almost as fine as human hair. Breathing machines overpowered fragile lungs. Medicine or nutrition could not be delivered in the precise, fractional measure needed. Some babies actually drowned when health care workers attempted to feed or medicate them using intravenous, gravity drips.

But the doctors and nurses kept trying, and learning. Mistakes that cost lives in 1973 became knowledge that saves lives today.

Catheters small enough for the infants were made and became common in nurseries. Engineers developed a micro-pump that splits a daily dose of liquid nutrition or medicine into fractional ounces and delivers the precise amount, drop by drop, through the catheters to the small, struggling humans.

Nutritionists learned how to feed babies by needle, helped by the micro- pumps to deliver the exact balance of sugar, fat and protein in small doses.

New ventilators were developed to deliver air to incubators at the exact pressure, temperature and humidity needed for tiny lungs.

Medical workers began to recognize that it was possible to save these small humans and the challenge attracted new talents. Doctors and nurses who might have chosen other types of medicine now worked with premature infants in the nursery.

″The possibility of intervention brings more people into the field,″ said Dr. Charlotte Catz of the National Institute of Child Care and Human Development, a part of the National Institutes of Health. ″The passive observer is not a very exciting thing.″

All of these factors worked together to slowly drop the viability age to 24 weeks.

″There hasn’t been a single breakthrough, but more a refinement,″ said Ernest N. Kraybill, a neonatal expert on the faculty at the University of North Carolina school of medicine. ″There’s been a refinement of both our technology and our ability to use it on very small babies. We’re now having the results with 700-gram babies that we once had with 1200-gram babies.″

The survival rate at the limit of viability, now less than 50 percent, may improve soon when researchers perfect an artificial surfactant, the protein that helps the lungs absorb oxygen. The new drug is now being tested in selected hospitals and appears to be successful in relieving some respiratory problems of the premature. But experts don’t expect the age of viability for preemies to ever drop below 24 weeks.

″In most species, premature babies just don’t live. Premature puppies don’t live. Premature sheep don’t live,″ said Dr. Edwards. ″There is a natural limit.″

″I think we are at the limit now,″ said Dr. Maria Delivoia-Papadopoulos, chief of perinatal services at the University of Pennsylvania Hospital. ″Below 24 weeks, the whole system - brain, lungs, heart - is not developed enough.″

More and more, doctors also are questioning whether society should push for survival below 24 weeks.

By some estimates, it takes about $1 million dollars to assure just a year’s survival for a baby born three months premature. And nearly all such children require later medical care to correct problems of prematurity.

″When you think about ... the tremendous cost for that purpose and contrast it with all the simple, inexpensive things that need to be done for bigger babies with better prospects of survival - such as immunization - it suggests that we maybe shouldn’t be investing resources into such extremely high technology for a tiny group of babies with such poor prospects,″ said Kraybill. ″Keeping 23-week babies alive may not be an appropriate national priority.″