pregnant vs up the duff

pregnant

adj
  • Of a couple: expecting a baby together. 

  • Fertile, prolific (usually of soil, ground, etc.). 

  • Having numerous possibilities or implications; full of promise; abounding in ability, resources, etc. 

  • Carrying developing offspring within the body. 

noun
  • A pregnant woman. 

up the duff

prep
  • Pregnant. 

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