Babies born prematurely at more than 4.4 pounds appear to benefit from preschool education longer than their lighter premature peers, according to recent research by an interdisciplinary team that includes psychologist Jeanne Brooks-Gunn, PhD, of Columbia University Teachers College.
In the study, published in Pediatrics (Vol. 117, No. 3, pages 771-780), researchers followed for 18 years low birth-weight children born prematurely at or before 37 weeks gestation. The researchers classified those born at 4.4 pounds or less as lighter preemies and those born at 4.4 to roughly 5.5 pounds as heavier.
The researchers randomly assigned one-third of almost 1,000 children--from eight sites nationwide and varying in ethnicity and socioeconomic status--to a treatment group and two-thirds to a follow-up group. Both groups received pediatric follow-up and referrals. The treatment group also received home visits and center-based education from professionals who had at least bachelor's degrees and child-development training. The children experienced home visits in their first three years of life and the center program in their second and third year of life. They also were offered transportation to the year-round, full-day center-based program. Professionals working with the children in their homes and in the centers used the "Learning Games" child-development curriculum.
Differences emerged between the lighter and heavier preemies who'd received the intervention: The researchers found apparent lasting benefits among the heavier preemies when they were 18 years old--a pattern also found in normal-weight children in previous longitudinal research, Brooks-Gunn notes. Lighter preemies did not show these sustained effects.
Specifically, heavier preemies performed notably better at age 18 on math and vocabulary testing. They also performed slightly better than lighter preemies on reading and IQ testing, but those results fell shy of significance. The groups showed no marked differences on behavioral and delinquency measures.
Previous testing of the cohort had revealed, however, that the lighter preemies did appear to benefit from the intervention at age 3. They and their heavier preemie peers both scored higher on IQ and behavioral testing than nonintervention children did. By ages 5 and 8, though, those IQ and behavioral benefits dropped away for the lighter group--as was also found in the 18-year follow-up.
Why the apparent loss of benefits for the lighter preemies? It could be they need higher doses of preschool services, speculates Brooks-Gunn. In this cohort, exposure to the educational intervention varied according to parents' schedules. A previous analysis of the same cohort, led by Jennifer Hill, PhD, and published with Brooks-Gunn and Jane Waldfogel, PhD, in 2003 in Developmental Psychology (Vol. 39, No. 4, pages 730-744), indicated that lighter preemies who spent more time in the educational center than their other comparatively light peers had higher achievement testing scores at ages 5 and 8.
"Clearly the big bang for preemies is high-quality, center-based care early on," says Brooks-Gunn. "But our results suggest that beyond that, we need kids to attend regularly."
In future analyses, Brooks-Gunn and her colleagues will assess if the high-dose lighter preemies saw sustained effects at age 18.
--B. Murray Law