"Baby brain" is a cliche long-used to describe women becoming forgetful and feeling less capable during pregnancy. But a recent study - the largest to date - indicates that pregnancy has a profound structural impact on brains and offers new clues into the neurological changes in mums‑to‑be. It suggests that grey matter - the nerve-rich part of the brain involved in processing information, emotions and empathy - decreases by an average of nearly 5% during pregnancy. But rather than being a cause