Preemies' Thinking Skills Catch Up by Adolescence?
Study hints at the importance of nutrition and a stimulating home environment
By Barbara Bronson Gray
TUESDAY, Aug. 12, 2014 (HealthDay News) -- A new Australian study offers some potentially reassuring news to parents of preemies who are worried about their child's intellectual development: By adolescence, many of these infants appear to catch up to classmates who weren't born early.
But some U.S. experts said the findings may be overly optimistic because only the healthiest premature babies were studied.
Premature infants are born more than three weeks before their due date, but brain volume typically doubles in those final weeks before birth, explained Dr. Deborah Campbell, chief of neonatology at Children's Hospital at Montefiore in New York City. "There is tremendous growth and activity in that last month," she said.
Without that time in the womb for the brain to develop normally, preemies can experience a wide range of issues, including thinking and memory problems. "Fifty percent of preemies will have learning problems," said Campbell.
The Australian researchers found the strongest predictors of thinking ability in teenagers who were born prematurely seemed to be a combination of factors that occurred both before and after birth, most particularly birth weight, height and socioeconomic level at the time of birth.
Of those factors, early nutrition and enrichment through physical and intellectual stimulation in the home environment are likely to have key roles, the study authors concluded. The research was published recently in The Journal of Pediatrics.
For the study, Luke Schneider and colleagues at the University of Adelaide looked at 145 adolescents who were born prematurely: 78 boys and 67 girls. Gestational age -- which is normally 40 to 42 weeks -- ranged from 25 to 41 weeks. None of the participants had abnormal brain ultrasounds at birth, any genetic or chromosomal disorder or known syndrome, or any physical or intellectual disability that would interfere with their ability to follow directions.
Data related to gestational age at birth, each teenager's birth weight and current height and weight, birth head circumference and socioeconomic level (based on their address at birth and parents' occupation, employment and income) were also collected. The thinking abilities of the teenagers were then assessed using standard tests.
The researchers noted that the only extremely preterm children who were included in the study were those with good fetal growth at the time of their birth. As a result, they said that the sample may not be representative of all preterm children, only the most neurologically normal.
One expert agreed that the research may not reflect the full spectrum of preemies.
"This is an abnormally rosy picture of preterm birth," said Dr. Catherine Herway, an assistant director of maternal-fetal medicine at Staten Island University Hospital, in New York City.
Herway added that she was concerned that research suggesting that problems of prematurity may be resolved by adolescence may fuel a current trend where women are asking that their babies be delivered a couple of weeks before their due date.