fecundity vs pregnancy

fecundity

noun
  • Ability to produce offspring. 

  • Ability to cause growth or increase. 

  • Number, rate, or capacity of offspring production. 

  • Rate of production of young by a female. 

pregnancy

noun
  • The progression of stages from conception to birth. 

  • The condition of being pregnant; an instance of this. 

  • The period of time this condition prevails. 

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