So, an observation in passing.

Season 10, episode 24, Thursday's Child, starring the great Jean Arthur. She plays Kitty's mentor (in salooning, I suppose) who comes to Dodge to (secretly) help deliver her outlaw son's wife deliver their child.  When the young wife keeps saying she's very very tired, Jean Arthur laughs quietly and tells her in that great throaty voice, "oh honey, you're just pregnant, that's all."

First use of that word on this show, probably an early use for American TV generally.  And along those lines:

Season 11, episode 7, The Bounty Hunter.  Robert Lansing finds out from the wife of his intended target that he beat a man to death because - that man had raped her.

 The first use of this word seems even more significant, since rape and the threat of rape are constant themes on Gunsmoke, usually presented in stomach-turningly low-key realistic ways. for example in season 3, episode 24, The Cabin. But the word was never spoken.