Passport for baby

I'm not sure if there is a post about this already or if I should even post it here but... Do I need to get a passport for the baby??  We have plans to travel to Portugal in July and baby is due in a week.  I don't know if I need to have a passport of not.  Can anyone point me in the right direction??

I'm living in the UK as an EU citizen and was thinking she could get a UK passport because it would be easier/faster.

here in the states you have to have a passport for ANY person traveling. Even if they are newborn. We did have a hard time finding someone to take the passport picture though. They went thru 3 rolls of film trying to get a picture that would be accepted!!! Good Luck!