The longest-running U.S. study of the effects of being born premature is a mixed bag of bad and good news: while the effects of prematurity can persist into adulthood, babies born too early are largely evolving into children and adults who are remarkably resilient.
On the one hand, premature babies struggle more in school and social situations, are less healthy and stand a greater chance of having heart-related problems as adults, reports Mary Sullivan, a professor of nursing at the University of Rhode Island and principal investigator of the study, which has tracked 213 infants who are now 23. But despite that, premature babies are also driven to succeed, a characteristic that can be encouraged by nurturing parents and supportive school environments. “We are seeing some continual effects of prematurity, but except for those who had severe illness as babies, many seem to do pretty well after they get over the initial preemie period,” says Sullivan, an adjunct professor of pediatrics at Brown University.
Study participants fall into five categories: a control group of full-term healthy infants and four cohorts of pre-term infants born between 24 to 34 weeks, weighing between 1 pound, 7 ounces and 3 pounds, 15 ounces. They have all taken part in nine waves of research — much of it funded by the National Institutes of Health — that assessed their IQ, functioning, sociability, behavior and academic abilities.
Researchers are now compiling data from when the children were 17 and are in the midst of collecting more information. Some of the preliminary findings from the latest phase of research include:
• Babies who suffered medical and neurological effects of pre-term birth had up to a 32% increased risk of asthma, vision problems and trouble with fine motor and hand-eye coordination.
• Babies born weighing less than 2.2 pounds (1,000 grams) had worse pulmonary outcomes and higher resting blood pressure than those who were heavier.
• Data from the children who were age 17 suggests that the pre-term group has poorer health, growth and neurological outcomes than those who were born full term.
• Being a boy and of low birth weight affects breathing when they reach early adulthood.
The multi-pronged study has concentrated on various aspects of prematurity; the latest focus is whether premature infants’ stress can translate into adult illness. It’s part of what’s known as the “fetal origins hypothesis,” which maintains that preemies’ response to stress can underpin chronic diseases of adulthood. When babies are born too early, delivery sets into motion a stress response, which is marked by accompanying higher levels of the hormone cortisol. Cortisol helps regulate metabolism and immune response, among other things, and Sullivan is comparing cortisol levels in the adults who were born pre-term with adults who were full-term babies.
Even pre-term babies who don’t have significant medical or neurological conditions are unlikely to escape some impact of prematurity. They don’t seem to have as many friends as healthy, full-term babies. Boys, in particular, struggle more in school. Learning disabilities, for example, may not manifest themselves until at least second grade, says Sullivan, who has reported that at least 30% of premature infants needed special academic accommodations at some point during their time in school.
At age 8, she notes, kids who appeared to have been doing pretty well seemed to have trouble in school. “There’s a need for continual vigilance and observation because you might think they’re doing okay but they’re actually not,” she says. “By second grade, when abstract concepts and more complex concepts come into play, we are seeing problems.”
That’s the bad news. On the flip side, however, Sullivan found that pre-term babies countered the effects of being born early by displaying a “persistent drive to succeed.” Pre-term babies with mothers who advocated for them in school also did better academically, socially and physically.
“There is a lot of great news about how well children do,” says Sullivan “We’re also looking at what helps children do well.”
One major factor: parents who are observant but not overprotective are the most effective advocates for their children when it comes to negotiating the health-care and school systems in order to help their child get the services they need. “They have to be persistent,” says Sullivan. Being born premature may put kids at a slight disadvantage when it comes to certain developmental milestones, but that doesn’t mean they can’t make up for them with the proper support.