Teens and adults who were born prematurely may have ‘older’ brains than those who were born full-term. It is the main conclusion of the study carried out by scientists from the Institute of Psychiatry of Psychology and Neuroscience of King’s College London (United Kingdom) and collected by the journal Neuroimage .
A baby’s brain is fully developed in the last weeks of gestation, so being born too early interrupts this process; hence, premature babies are at higher risk of developing disabilities, including problems with learning, language, and behavior.
But how does premature birth affect the brain in adulthood?
The brain does not fully mature until we reach 25 years of age, and there are even areas of the brain that do not mature until the age of 36 (specifically the cortex that is responsible for visual perception), showing that this magnificent plastic organ is changing and developing lifelong.
However, the experts wanted to investigate how preterm labor could affect the adult’s brain maturation process.
Using MRI, the researchers analyzed the brain structure of 328 adults who were born before 33 weeks’ gestation. The subjects were evaluated at two moments: adolescence (mean age 19.8 years) and adulthood (mean age 30.6 years).
The brain scans of these participants were compared with those of 232 full-term adults (control subjects), along with 1,210 brain scans obtained from open access MRI archives.
Specifically, the researchers examined the volume of gray matter in the participants’ brains, as a marker of “brain age.”
Acceleration of brain maturation
Compared with control subjects, the team found that prematurely born subjects had less gray matter volume in adolescence and adulthood, particularly in brain regions associated with memory and emotional processing.
They also pointed to a series of structural brain abnormalities that demonstrated resistance to the effects of preterm birth. For example, they identified increased gray matter volume in regions associated with behavioral control.
“Although one can only speculate about the functional significance of these alterations, previous studies suggested that compensatory mechanisms may support language and cognitive processing in samples of the very preterm,” the authors write.
Upon further investigation, the scientists found that the reduced gray matter volume identified in premature infants was associated with accelerated brain maturation. As a result, the brains of the premature subjects appeared older than those of the control subjects.
“The finding of structural signatures of accelerated brain maturation in those born prematurely was unexpected “, explains Vjaceslavs Karolis, leader of the work.
The authors cannot explain how these structural brain changes identified in adolescents and premature adults translate into everyday functioning, but they believe this is something that should be investigated in the future.
Reference: Volumetric gray matter alterations in adolescents and adults born very preterm suggest accelerated brain maturation. NeuroImage2017. doi.org/10.1016/j.neuroimage.2017.09.039
