Is it true that much of the really important brain development happens in the first trimester?

The brain starts to form soon after conception – brain cells begin to form at the tip of the embryo. After about three weeks, the neural tube begins to change in order to form the spinal cord and the brain. Brain cells (neurones) start to develop and send messages to each other.

At first, brain cells multiply at a rate of about 250,000 per minute. This slows down after about twenty weeks of pregnancy as the brain has to have a chance to organise itself into over forty systems to direct vision, language, movement, hearing and other functions.

By the time the half-way point of pregnancy has been reached, almost all the brain cells needed for life are present. During the last trimester, the connections between the brain cells mature and the baby’s nervous system becomes more developed. Many important brain connections that help to determine personality develop after birth. ¹

Omega 3 fatty acid is thought to play an important part in an unborn baby’s brain development. It can be found in oily fish, but you can also buy an omega 3 supplement specifically designed to take during pregnancy.

So, it is possible to see that fetal brain development occurs throughout pregnancy, and after, but crucial foundations are certainly laid during the first three months.

¹ Sadler 2006: “Langman’s Medical Embryology”