All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Ash-Shaatibi stated in his book Al-Muwaafaqaat that the purpose and meaning are what counts in custom, as opposed to acts of worship. He
wrote, "The basic principle in acts of worship is compliance/submission without consideration of meaning/relevance; whereas in custom, the basic principle is consideration of meaning/relevance.”
Celebrating the coming of a baby is an expression of joy and happiness and this is a purpose approved by the Sharee‘ah. Therefore, such a custom is not held impermissible unless it involves a violation of the Sharee‘ah.
Allaah Knows best.