Some Catholic and other denominations view infant baptism and baby dedication differently. We do not baptize babies or small children since we believe that this happens when they are old enough to make a choice to follow Jesus. Child Dedication is really more about the parents publicly showing that they desire to raise their child and family in the way of the Lord Jesus Christ.
Christian Child dedication (from the Protestant perspective) is a symbolic ceremony undertaken by Christian parents soon after the birth of a child but also by parents who have older children who never were given the opportunity to dedicate their infant at a local church. The rite is intended to be a public statement by the parents that they will train their children in the Christian faith and seek to instill that faith in them. The congregation and family and friends affirm that they, as a church family, will also seek to encourage the parents to bring up the child in the faith. There is no implied salvation in the ceremony, it is a dedication of the child to the Lord. Infant baptism is a different matter. Churches that perform infant baptism usually tie salvation into it but as a Protestant church, we believe in infant and child dedication and baptism happens when the child or young adult makes a confession of faith in Jesus for salvation and then decided to get baptized to make a public profession of the inward faith that they have.
The idea of dedicating a child to the Lord can certainly be found in the Bible. Hannah was a barren wife who promised to dedicate her child to God if He would give her a son in 1 Samuel 1:11. Luke 2:22 begins the account of Mary and Joseph taking Jesus to the temple after forty days in order to dedicate Him to the Lord. This was slightly more involved since it involved a sacrifice, but once again this ceremony did not indicate any level of salvation.
Child / baby dedication is not one of the two ordinances—baptism and the Lord’s Supper—required of Christians in the New Testament. As Christians, we are baptized and participate in the Lord’s Supper as outward and public signs of what Christ has done within us. While baby dedication is not an officially instituted ordinance of the church, there does not seem to be any conflict with Scripture as long as parents do not view it as assuring the salvation of the child.