baby brainnoun [ U ]
/ˈbeɪ.bi ˌbreɪn//ˈbeɪ.bi ˌbreɪn/informalthe condition of forgetting things and not being able to think clearly that pregnant women are often said to experience:
Baby brain makes you feel so silly when you forget the most basic things.
I was pregnant with my second baby and my baby brain was in full force!
How could I make such a dumb mistake? My mum said maybe it was baby brain.