One lead researcher considers 22 weeks a new marker of viability
By Dave Andrusko
The results of a massive study of nearly 5,000 extremely premature babies published last Wednesday in the New England Journal of Medicine found that the survival rate of babies born at 22 and 23 weeks increased substantially if hospitals actively treat the babies.
NEJM study shows nearly a quarter of babies born at 22 weeks survive if actively treated; 33% for babies born at 23 weeks.
Likewise the severity of disabilities was lessened when these very young babies were actively treated.
Active treatment (as opposed to comfort care) included assistance in breathing, feeding tubes, and surfactant to improve the babies’ lungs.
The study, funded by the NIH, ran between April 2006 and March 2011. The analysis examined 4,987 babies who born before reaching 27 weeks of gestation.
When Roe v. Wade was handed down, 28 weeks was thought to represent the threshold for “viability.” But the medical consensus figure has not only dropped to 24 weeks but more and more hospitals are now treating babies born at 22 and 23 weeks, according to the NEJM study.
But not all.
According to the Associated Press’ Marilynn Marchione
Researchers looked at rates of comfort care versus active treatment, such as breathing machines, feeding tubes or heart resuscitation. Active treatment was given to 22 percent of babies born at 22 weeks, 72 percent of those at 23 weeks and nearly all beyond that.
Survival rates were higher for the actively treated babies — 23 percent versus 5 percent for all babies in the study born at 22 weeks, and 33 percent versus 24 percent for those born at 23 weeks.
Survival without severe impairment also was higher with treatment: 15 percent versus 3 percent at 22 weeks, and 25 percent versus 18 percent at 23 weeks.
Four hospitals never actively treated babies at 22 weeks, but five other hospitals always did.
Two of the study leaders– Dr. Edward Bell of the University of Iowa and University of Iowa medical student Matthew Rysavy–talked to various publications to explain what their findings represented.
Dr. Bell told the New York Times’ Pam Belluck that at Iowa,
treatment is offered to most 22-week-olds, and he considers 22 weeks a new marker of viability.
“That’s what we think, but this is a pretty controversial area,” Dr. Bell said. “I guess we would say that these babies deserve a chance.”
Dr. Bell told the Associated Press that parents need to know that “the hospital that you go to might determine what happens to your baby,” although he acknowledged that many parents, when they find themselves in these emergency situations, do not have the opportunity to shop around.
Marchione continued that parents
also should be given better information on survival odds — not just by gestational age but also by what happens if active care is given, said another study leader, medical student Matthew Rysavy.
“A doctor might say ‘no 22-week infant has ever survived,’” but that might mask the fact that doctors there don’t try, because they don’t consider such babies viable, he said.
Belluck also noted that
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, and if you do something, some of them will make it,” said Dr. David Burchfield, the chief of neonatology at the University of Florida, who was not involved in the research.
But others quoted in the stories disagreed that babies this young should be actively treated, especially when many who survive will have disabilities.
Dr. Jonathan Muraskas, a neonatologist at Loyola University Medical Center in Maywood, Illinois, told the Times. “We just seem to be resuscitating more and more tinier babies, and there are consequences.” He added, “How low do we go and what are the implications?”
But by and large, there was much more optimism than pessimism in the coverage and some stories not only cited success stories but also cautioned about how imprecise estimates of fetal age can be. Belluck noted
The authors and other experts also noted that gestational age is an educated guess, based on women’s recollection of their last menstrual period and estimated fetal size. Other factors, including prenatal care and the fact that girls are often a week more mature than boys, should also influence decisions, experts say.
“It’s very difficult to say to a mother, ‘If you deliver today, I’m going to do nothing, but if you deliver tomorrow, I’m going to do everything,’ ” said Dr. Neil Marlow, a neonatologist at University College London.