in utero vs initiatory

in utero

adj
  • Occurring or residing within the uterus or womb. 

adv
  • Occurring or residing within the uterus or womb. 

initiatory

adj
  • Of or pertaining to initiation 

  • inceptive, initial, inaugural or introductory 

noun
  • An introductory act or rite. 

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