Written with people moving from Turkey in mind. The Portuguese rules still apply more broadly.
Citizenship for Babies Born Here
Children born in Portugal to foreign parents are automatically entitled to Portuguese citizenship if at least one parent has legally resided in the country for at least one year at the time of birth.
This applies even if the parent holds a temporary residence permit. You can register the baby directly at the maternity ward or a Civil Registry office, granting them an EU passport immediately.