A premature baby boy in an intensive care unit at a hospital. (iStock)

In hospitals where extremely premature babies are given intensive care, a small fraction of infants are surviving outside the womb earlier than was once believed possible.

That finding, from a study published Thursday in the New England Journal of Medicine, is heartening news in the world of pediatrics. But it also adds to a list of questions for parents, doctors and lawmakers by challenging the accepted age for “viability” — a standard that has defined the debates about abortion and intensive neonatal care.

Researchers examined the cases of nearly 5,000 infants born before 27 weeks after conception (most are born at week 40 of pregnancy) and found that hospital-to-hospital variations in how and whether they treated preemies significantly affected whether the babies lived. Among those born at 22 weeks — two weeks before the accepted 24-week standard for viability — babies had a nearly 1 in 4 chance of survival if actively treated. If a newborn’s parents and doctors decided not to pursue treatment, the baby had no chance at all.

According to Neil Marlow, a neonatology expert at University College London, many doctors have assumed that 22 weeks was too early for a child to be a candidate for intensive care because fatality rates were so high. But the NEJM study shows that those high rates are in part due to doctors’ reluctance to attempt a painful intervention on a newborn that’s unlikely to survive.

Telling parents that almost no newborns survive at 22 weeks without clarifying that few are given active care “helps to make poor survival a self-fulfilling prophecy,” Marlow wrote in an editorial accompanying the study.

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Edward Bell, a pediatrics professor at the University of Iowa and a co-author of the study, told the New York Times he considers 22 weeks a new marker of viability — a newborn’s potential to survive outside the womb.

“That’s what we think, but this is a pretty controversial area,” he said. “I guess we would say that these babies deserve a chance.”

The vast majority of the hospitals in the study agree with Bell — all but four of the 24 institutions examined offered active care to all or some of the babies born at 22 weeks. If he is right that 22 weeks has become the new age of viability, it could have implications far beyond the delivery room.

That’s because the Supreme Court has long crafted its abortion rulings around the idea of viability. In Roe v. Wade the court ruled that states could not restrict abortions before the 28th week of pregnancy, at the time thought to be the earliest a newborn could survive on its own.

The 1992 case Planned Parenthood v. Casey, acknowledging that advances in neonatal care made survival of even more premature babies possible, detached the “viability” marker from the 28-week standard but left the sentiment of the original ruling intact: “We reaffirm … the right of the woman to choose to have an abortion before viability and to obtain it without undue interference from the State,” read the majority opinion.

That standard is reflected in most state laws on abortion. According to the Guttmacher Institute, which advocates for reproductive health, the majority of states that limit abortion after a certain point of pregnancy peg their restrictions to either 24 weeks or a more vaguely defined point of viability.

Aside from the legal implications, the study has prompted ethical questions among doctors who work in neonatal care. Though 24-week babies are nearly always given treatment to help them survive, the slim chances for 23- and 22-week newborns makes the decision to pursue active treatment more difficult.

“We just seem to be resuscitating more and more tinier babies, and there are consequences,” Jonathan Muraskas, a neonatologist at Loyola University Medical Center in Illinois, told the Associated Press. These children are more likely to have cerebral palsy, blindness, deafness and asthma. Even though more premature babies are surviving, the rates of these medical problems have not changed.

“How low do we go and what are the implications?” he said.

Ian R. Holzman, chief of the division of newborn medicine at the Icahn School of Medicine at Mount Sinai in New York City, told the site MedPage Today that there is no one answer to the viability question.

“In an area with many philosophical issues, it is not possible to have a blanket policy on initiation of treatment,” he said. “Families need to be a part of that discussion as does society.”

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