the baby takes the nationality of its parents ....
in the past, this would 'automatically' be that of the Father ...
Times have changed, and in smany countries this old rule no longer applies -
so if you are a german married to a spaniard, living as residents in Spain ...... the baby would be granted spanish nationality ..... if you made application / notified authorities --------- residents here means where the authorities recognise the parents as being domiciled / ordinarily resident ......... although terminology is different in european countries....
so easy way is to apply for european citizenship !!!!!!!!! (does not exist yet)