Hello Shanefinlan,

Your baby will have Vietnamese Nationality, as Vietman recognizes as Vietnamese Nationals those children born to Vietnamese Nationals outside the country. Therefore, as your baby won´t be regarded stateless, he will be born Vietnamese and will hold the same residency status as his/her parents. After one year holding the residency status, you will be able to apply for his/her Spanish Nationality as he/she has been born in Spain. You can check this information here.

Regards,