A new study of thousands of premature births found that a small minority of babies born a week or two before what is now generally considered the point of viability can be treated and survive, in some cases with relatively few health problems.
While the odds of success are long, they are nonetheless likely to intensify the agonising decisions that parents and doctors face about whether to actively treat a baby born as early as 22 weeks into pregnancy.
The study, one of the largest and most systematic examinations of care for very premature infants, found that hospitals with sophisticated neonatal units varied widely in their approach to 22-week-olds, ranging from a few that offer no active medical treatment to a handful that assertively treat most cases with measures like ventilation, intubation and surfactant to improve the functioning of babies' lungs.
"It confirms that if you don't do anything, these babies will not make it, but if you do something, some of them will make it," said Dr David Burchfield, chief of neonatology at the University of Florida. "Many who have survived have survived with severe handicaps."
Results of the study, published on Wednesday in The New England Journal of Medicine, are likely to influence a discussion taking place among medical professionals about how to counsel parents and when to offer treatment to such tiny babies.
The findings may also have implications for the abortion debate. In the US the Supreme Court has said states cannot ban abortion before a foetus is viable outside the womb, and 24 weeks has generally been cited by medical experts as the estimated time of viability.
Recently, physicians who work with very premature infants have begun to consider it reasonable to offer parents active medical treatment for babies born at 23 weeks. A 2014 summary of a workshop that involved the American College of Obstetricians and Gynecologists and the American Academy of Pediatrics said that "in general, those born at 23 weeks of gestation should be considered potentially viable" because more than a quarter of such babies survive when treated intensively.
The report said nothing helps babies less than 22 weeks old to survive.
But babies born between 22 and 23 weeks are a question mark. Their chances for survival slim but vary as a result of birth weight and whether the mother received corticosteroid treatment, which can help the baby's lungs and brain, before delivery.
The study, involving nearly 5000 babies born between 22 and 27 weeks gestation, found that 22-week-old babies did not survive without medical intervention. In the 78 cases where active treatment was given, 18 survived, and by the time they were young toddlers, seven of those did not have moderate or severe impairments. Six had serious problems such as blindness, deafness or severe cerebral palsy.
Of the 755 babies born at 23 weeks, active treatment was given to 542. About a third of those survived, and about half of the survivors had no significant problems.
As techniques for keeping babies alive improve, parents face wrenching choices that are sometimes based on whether the estimated age is 22 weeks and one day or six days. Indeed, the study found that hospitals tend to "round up" with babies closer to 23 weeks more likely to receive treatment.
Matthew Rysavy, a medical student at the University of Iowa, who led the study with Dr. Edward Bell, pointed to Chrissy Hutchinson, 32, as a success story. Her water broke in 2010 when she was 21 weeks and six days pregnant. The first hospital she went to "said there really was no chance of survival, and if the baby was born not breathing that they weren't going to resuscitate or anything," she said.
The Hutchinsons called the University of Iowa, and there, at 22 weeks and one day, Alexis was delivered, weighing 1.1 pounds (499g). Alexis was treated and stayed in neonatal intensive care for almost five months.
Now, aside from being more vulnerable to respiratory viruses, Alexis is a healthy 5-year-old.
Some of the study's results suggest that among 22-week-olds who are treated, experiences like the Hutchinsons' would be exceedingly rare because she delivered so close to 22 weeks and did not have time for corticosteroids beforehand.
Another couple, Danielle Pickering and her husband Clayton, chose treatment when Danielle was hospitalised at 22 weeks. She received corticosteroids and delivered baby Micah four days later. He spent more than four months in intensive care, had heart surgery and was "one of the sickest babies" there.
Fortunately, now, "he is a spunky almost 3-year-old" with chronic lung disease and a slight speech delay.
"We figured he was our baby, and he was what the Lord had given us, and we would just do everything we could," the proud mum said.
New York Times