NEW YORK – Over the past 15 years, survival rates among infants born extremely early (before 24 weeks of pregnancy) have not improved, but it's not for lack of trying.
According to a UK study released today, there has been an increase in the number of extremely preterm babies receiving active, yet ultimately unsuccessful, treatment. These tiny babies are surviving a bit longer today than in the past, but it's measured in hours.
"The reality is that over the years we are getting better; survival is improving at 24 weeks and above, and serious outcomes (bad cerebral palsy) are less," Dr. Nick Embleton of Newcastle Neonatal Service, Royal Victoria Infirmary, Newcastle upon Tyne, told Reuters Health by email.
"But there has been no consistent improvement with birth at 23 weeks, either because we are right at the edge of what is possible or because we still have more to learn. It might be that we need more experience," he said.
But to put it in perspective, Embleton noted: "When neonatal care started out, you were lucky to survive at 28 weeks; now you have a 50 percent chance at 24 weeks. So maybe another 5 years will tell." Currently, a baby born at 23 weeks has about a 20 percent chance of surviving.
A normal pregnancy lasts 40 weeks. It is not clear how many babies born after only 22 or 23 weeks of pregnancy, which is considered the margin of viability, are offered active treatment.
The new study, spanning 15 years, indicates that babies born at this tender "gestational age" are increasingly actively resuscitated and treated and for significantly longer -- but with no overall improvement in outcome.
The researchers analyzed data on all 480,662 live births that occurred between 1993 and 2007 in one region in the north of England. Just 229 of these babies, or 0.05 percent, were born alive after just 22 or 23 completed weeks of pregnancy and 210 of them died (92 percent).
Aided by intensive care, 71 of these infants (34 percent) lived for more than 6 hours and the length of time alive gradually increased over the years. From 1993 to 1997, average survival time of babies who died but were actively treated was 11 hours; it jumped to 20 hours from 1998 to 2002, and 3.7 days from 2003 to 2007.
Keeping these tiny babies alive, even for a few hours, takes "a real team approach; it's definitely not due to heroic medical actions," Embleton said. "Very occasionally these small babies need some complex procedure like an operation -- and that might be considered heroic -- but that is the minority. Improvements are due to tiny improvements in a multitude of different processes so you can't put your finger on a specific one."
As time went on, the number of babies ultimately surviving did not go up, the researchers report. Among the small group of 19 survivors over the 15-year period, 6 survived between 1993 and 1997; 6 survived between 1997 and 2002; and 7 survived between 2003 and 2007.
When to Say No
Guidelines published in the UK last year recommend that, "in the best interests of the baby," resuscitation not be performed in infants born at 22 weeks, if that gestational age is "certain." At 23 weeks, the guidelines state, resuscitation should be an option if the fetal heartbeat is heard during labor; the heart response is then critical in deciding whether to continue or stop resuscitation.
For extremely preterm infants, the cutoff point for providing active care remains an "extremely contentious" issue, mainly among doctors, Embleton said.
"Many (doctors) would not offer resuscitation to babies at 23 weeks because the chances of survival are so small, and because as doctors there always comes a limit to what is 'reasonable'," he explained. "Doctors are also concerned that many who do survive have problems."
New parents, on the other hand, often push for treatment at 23 weeks. "Our local (anecdotal) experience is that most parents request an active approach immediately after delivery at 23 weeks (of pregnancy), despite counseling from experienced doctors using nationally consistent survival data," the investigators note in their report.
While the current study was conducted in the north of England, Embleton thinks studies on survival and resource use for births at 23 weeks in other developed countries would "almost certainly" yield similar results. "Except where there have been clear decisions never to offer support to very small babies (e.g., Holland)."
"But, importantly, even in Holland, they are struggling with not providing care," Embleton said. "These babies appear wriggling and breathing - it is very hard not to help them even though you know the chances of survival are small. That is human nature."
He added that he thinks it unlikely there will ever be a consistent improvement among infants born at 22 weeks, but it's possible there will be advances for those born at 23 weeks.
The researcher also made this point: "There would be no other branch of pediatrics or medicine where a 1 in 5 (20 percent) chance of survival would be deemed too small."
Embleton is of the opinion that: "financially, it is a no-brainer. Yes, a survivor uses a lot of resource -- maybe $200,000 for hospital care, and more afterwards if they have problems. But that might get you 60 years of life; set alongside that, it is far cheaper than cancer treatment."