He collaborated with Bing & Grøndahl, Saxbo and Dahl Jensen Porcelain and also designed silver for Kay Bojesen.

He worked as a decorative sculptor in stucco artist Hans Lamberg-Petersen's workshop in Copenhagen from 1902 to 1905 and then continued his studies in Italy, France and Germany until 1908.

From 1907 to 1911, Bregnø created a number of ceramic works that were burnt in Patrick Nordström's workshop in Islev.

[1] He later created numerous statuettes for Bing & Grøndahl in collaboration with the company's artistic director Hans Tegner.

Bregnø also created unica works in his own name that were burnt at different workshops, including Saxbo in Herlev and Hjorth in Rønne on Bornholm.