Reviewing the Utuado birth registries I bumped into an Aviles Perez family which registered all 9 of their kids on the same day.
Parents: Avelino Avilez Hernandez and Victoria Perez Sanchez.
These records can be found at https://familysearch.org/pal:/MM9.3.1/TH-1-9794-5610-40?cc=1...
Familysearch.org - Puerto Rico Civil Registries - 1911-1914 Births pgs 1082-1089. Happy Huntings!
I am not researching this family but I like to post good finds like this for those that are searching.