The brain has a longer duration of development than any other organ. This, combined with its enormous complexity of regional interaction, accounts for its relatively high degree of major congenital malformation.
The formation of the brain begins with the appearance of the neural groove at 20 days post-conception, and the development of neurones and their connections carries on throughout pregnancy up until 2-3 years of age.
Only a small proportion of major congenital CNS abnormalities produce external changes.
Last reviewed 01/2018