To give an infant the best start in life is, to some degree, a matter of time. It takes about 40 weeks to make a baby, or at least that is the ideal period. Babies can be born before this time of course, and anyone born before 37 weeks after conception is regarded as being born preterm.

There are often problems with a lack of development in preterm babies, particularly with the lungs. In fact, babies born before 23 weeks are not considered viable; there is no legal obligation for doctors in the UK for instance to resusitate babies born before this age.

The final few weeks before a full term birth is critical for brain development and researchers at Imperial College London have carried out work that casts some light on the nature and significance of the developmental problems of the brains of babies born before 30 weeks.

The study was based on a sample of 82 babies. Magnetic resonance imaging (MRI) scans were carried out of the brains of infants between the ages of 24 to 44 weeks (some of these babies weighed less than 700 grams or around about 1 1/2 pounds), and these were compared to cognitive tests on the children at the ages of 2 and 6 years. These tests evaluated attention, language, memory, planning and the ability to conceptualise numbers.

Comparing the overall brain volume to performance on the tests showed that there was no link. This means that bigger brains in babies doesn’t necessarily lead on to more intelligent 6 year olds.

The significant finding of the study however was the relationship between the outer layer of the brain, the cerebral cortex, and cognitive ability. The researchers compared the surface area of the cerebral cortex at 40 weeks and found that a 5-10% reduction resulted in significantly lower scores on intelligence tests later in life.

As the cerebral cortex is responsible for cognitive functions this relationship may not be a complete surprise but nevertheless should illuminate some of the background to problems experienced by preterm babies. In turn this may one day provide a focus for a treatment so that those that have a premature start to life don’t suffer long term consequences.

See the original article at Perinatal cortical growth and childhood neurocognitive abilities