Visa is provided for new born babies who are less than 3 months upon their arrival along with his/her mother at the entry border.

Requirements:

The baby should have a passport or his/her name should be added in the passport of mother or father.

To produce original birth certificate of the baby

The father and mother should have a valid residence permit in Qatar.

Official Link
https://www.moi.gov.qa/site/english/departments/PassportDept/news/2011/0...