A new study published in the online edition of the journal Radiology suggests that babies who are born after 32 and 36 weeks after gestation may develop smaller brains and other brain abnormalities, leading to long-term developmental problems.
Much of the existing knowledge on preterm birth and brain development has been drawn from studies of individuals born very preterm, or less than 32 weeks into gestation at birth.
For the new study, researchers in Australia focused on moderate and late preterm (MLPT) babies —those born between 32 weeks, zero days, and 36 weeks, six days, into gestation. MLPT babies account for approximately 80 percent of all preterm births and are responsible for much of the rise in the rates of preterm birth over the last 20 years. Despite this, to date there have been no large-scale studies published on brain alterations associated with MLPT birth that may provide insight into brain-behavior relationships in this group of children.
"In those very preterm babies, brain injury from bleeding into the brain or a lack of blood flow, oxygen or nutrition to the brain may explain some of the abnormal brain development that occurs," said the study's lead author, Jennifer M. Walsh, M.B.B.Ch., B.A.O., M.R.C.P.I., from the Royal Women's Hospital in Melbourne, Australia. "However, in some preterm babies, there may be no obvious explanation for why their brain development appears slow compared with babies born on time."