The fetus is about 45cm long and weighs 2.8kg. The fine, downy hair (lanugo) which covered it now disappears, and a little fat starts to accumulate under the skin.
The brain grows particularly rapidly at this stage: it now weighs a little over 300 grams, and will also grow significantly after the birth, throughout the first few years of life. At birth, the brain weighs 350 to 400 grams. An adult brain weighs around 1400 grams.
As baby develops, acquires new experiences and becomes capable of new things every day, the brain grows and more specialised neural circuits become 'wired'.