maternity vs parentage

maternity

noun
  • The state of being a mother; motherhood. 

  • The state of being pregnant; pregnancy. 

  • A ward or department in a hospital in which babies are born. 

parentage

noun
  • The identity and nature of one's parents, and in particular, the legitimacy of one's birth. 

  • The social quality of one's class in society. 

  • Origin; derivation. 

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