Do you need the child's birth certificate to christen the child?

The law varies from state to state and from country to country.

In the United States, if you do not supply a name for the baby in enough time before the birth certificate is issued, the certificate will bear the first name "Baby Girl" or "Baby Boy" followed by the last name of the mother.

The certificate can be amended later, when the parents decide which name to give the child. Until, then, the child's legal name is "Baby Girl" or "Baby Boy".