I would probably want to wait until after the baby was born to include the birth date of the baby. I'd probably include something like: Tumbling Baby BLocks, Made in honor of the birth of Baby Blue, born on 0/0/0000, son/daughter of Momma Mary (b 4/8/2222) and Daddy Donny (b 4/7/8888). Given by momma's Auntie Em, made & quilted by Your name, Peaceful, PA , completion date.
I try to include as much of the history as possible...