Baptism must follow understanding and belief...
In every recorded instance of baptism in Scripture, it applies to those who were mature enough to understand and believe the Gospel message. Infants are in no position to understand and believe.
Afterward he appeared unto the eleven as they sat at meat, and upbraided them with their unbelief and hardness of heart, because they believed not them which had seen him after he was risen. And he said unto them, Go ye into all the world, and preach the gospel to every creature. He that believeth and is baptized shall be saved; but he that believeth not shall be damned.
But when they believed Philip preaching the things concerning the kingdom of God, and the name of Jesus Christ, they were baptized, both men and women.