Italian to English Law/Patents Certificates, Diplomas, Licenses, CVs Declaration of natural child

This is a Modello D, declaring the birth of a child to natural parents. The birth is dated 2005, and the form completed on the same day. I am away of the reform of laws, regarding the child's parental links in terms of birth out of wedlock, since then, and am simply looking for good English usage for the translation of "contemporaneamente":

ATTO DI DICIARAZIONE DI NASCITA
(Figli naturali riconosciuti contemporaneamente del padre e Della madre)
Modello D....