birth name vs forename

birth name

noun
  • A name chosen for a child at birth, as opposed to a different name used subsequently. 

forename

noun
  • A name that precedes the surname. 

verb
  • Synonym of prenominate 

  • To assign (someone) a first name. 

  • To appoint in advance. 

How often have the words birth name and forename occurred in a corpus of books? (source: Google Ngram Viewer )