fetal vs unborn

fetal

adj
  • Pertaining to, or connected with, a fetus. 

unborn

adj
  • Not yet delivered; still existing in the mother's womb. 

  • Not yet born; yet to come; future. 

  • Existing without birth or beginning. 

noun
  • A single unborn offspring at any stage of gestation. 

  • Unborn offspring collectively. 

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