Some parents might want to celebrate the gift of a child but without the commitment that baptism involves. During the Thanksgiving service parents and families give thanks for the birth or adoption of a child and everyone prays for family life. It can take place in church with the congregation, or with just family and friends gathered, or elsewhere such as home, or even in hospital.
A Thanksgiving Service is not a Baptism. There are no promises to make about the Christian faith. The child will be blessed and prayed for, and supporting friends will promise to support the parents in bringing up their baby.