The link between preterm birth and risk of lower academic achievement has been established in a number of studies. But new research suggests that – when it comes to brain development – even for full-term babies, every week counts. Scientists have now found that babies born at the earlier end of the “full-term” range are more likely to have lower reading and math scores in third grade than those born just a few weeks later.
Researchers from Columbia University, Morgan Stanley Children’s Hospital and Mount Sinai School of Medicine started with birth records for all singleton babies born to mothers residing in New York City from 1988 to 1992. They then matched the records for those born between 37 and 41 weeks’ gestation (the range considered “full term”) with those same children’s third grade reading and math scores on standardized tests administered in New York City public schools.
In all, they matched records for more than 128,000 children, a group large enough to add significance to their findings. In general, test scores in both reading and math improved for each additional week babies spent in the womb. The most significant deficits were found in children born at 37 and 38 weeks.
Children born at 37 weeks’ gestation had a 14% greater risk of having mild reading impairment, 23% greater risk of having moderate reading impairment and 33% greater risk of having severe reading impairment than those born at 41 weeks. They also had a 16% greater risk of mild and 19% greater risk of moderate math impairment.
This was true even when researchers took a host of other factors that could hamper academic achievement – from the number of years a mother spent in school to lack of prenatal care, substance abuse, history of smoking, race/ethnicity and characteristics of the neighborhood where the mother resided – into account.
The study’s authors note that babies’ brains are growing rapidly between 37 and 41 weeks’ gestation, increasing their gray matter 50% and their white matter threefold. Being in the uterus, they say, likely supports this development. “Early term birth,” as the authors call it, could disrupt this growth. Based on their findings, the authors have two take-home messages for parents and doctors.
First, women and doctors planning early deliveries for nonmedical reasons should consider the potential impact of their decisions – which, as this study shows, lasts at least into elementary school. And second, pediatricians and parents should watch “early term” children in case they need extra educational support.
The study was published online July 2, and in the August issue of Pediatrics.