WEDNESDAY, June 6, 2018 (HealthDay News) -- Babies born prematurely or very small may not fare as well in life as those born full-term, a new research review suggests.
Adults who were born tiny or early may be more likely to lag behind educationally and professionally. They're also more likely to use social services, according to the review of 23 prior studies from eight countries.
Preterm birth occurs before the 37th week of pregnancy. The difficulties reported in the new study were greater for those born very prematurely -- before 32 weeks.
Despite the findings, study lead author Dieter Wolke stressed that people born early or at a low birth weight are not destined to struggle in adulthood.
"Most preterm-born adults are in employment and live independently. Most do well according to these markers," said Wolke, a professor of psychology at the University of Warwick in Coventry, England.
The studies involved more than 5.9 million adults in all. They were conducted across the United States, the United Kingdom, Canada, Denmark, Finland, Germany, Norway and Sweden.
Nearly 272,000 participants had been born before 37 weeks or weighed less than 5.5 pounds.
In adulthood, this group was less likely to have gone on to college, less likely to have a job, and more likely to receive social benefits, compared with their full-term peers, the study review found.
These odds tended to rise with the degree of prematurity, especially educationally.
The achievement markers were viewed as stand-ins for overall adult wealth. In other words, preemies were more likely to have financial problems as adults than babies carried to full-term.
Dr. Lisa Waddell, deputy medical officer of the March of Dimes, said these are "important" findings.
"They point out a clear association between preterm birth and adverse consequences down the road," she said.
"While we know that there are clinical consequences, this points out the impacts of preterm birth may have a long-term impact on the child into adulthood," added Waddell, who wasn't involved with the research.
Globally, about 11 percent of children are born prematurely. And nearly 9 percent of those are born in industrialized nations, according to background notes with the study.
Wolke said prior research suggests "super-sensitive" parenting is critical for helping these early, undersized arrivals to do as well as their average full-term peers.
But he cautioned that more research is needed to pinpoint the best way to foster and maximize resilience among preemies as they develop.
The news wasn't all troubling: No difference was seen between preemies and full-term births in the ability to live independently as an adult, though Wolke cautioned that this latter finding "requires further investigation."
What exactly might explain the findings? Wolke said that's difficult to say, because of differences among the studies.
He noted, for example, that not all the studies analyzed neurological deficits among preemies. That's one possible driver, among many, behind the findings, he said.
"Neurological deficits and disability will be part of the explanation," Wolke said. He added such deficits tend to be minor among premature babies born relatively close to full-term.
Waddell said the findings "really reinforce the urgent need to reduce the numbers of preterm births and especially those born very preterm."
Premature birth and its consequences are the leading contributor to deaths in the first year of life, she said.
"If we are going to give every baby the best possible start in life and the opportunity to grow, live, thrive and change the world, we must support the health of women before, during and after her pregnancy," said Waddell.
The findings appear in the June 6 online edition of Pediatrics.
There's more on premature births and related risks at the March of Dimes.