up the duff

up the duff

Pregnant. Primarily heard in UK, Ireland. You two have only been married for a couple of months, I can't believe you're up the duff already! I was pretty wild during my university years, which is how I found myself up the duff at 22.
See also: duff, up
Farlex Dictionary of Idioms.

up the duff

pregnant. British informal
1994 Daily Telegraph At 19, he was married (‘only because she was up the duff’ he explains gallantly).
See also: duff, up
Farlex Partner Idioms Dictionary
See also:
  • be up the duff
  • duff
  • be/go up the spout
  • be up the spout
  • spout
  • be up the stick
  • be up the pole
  • not quite the thing
  • great with child
  • knobstick wedding