Jon Marin wrote on A.I.M.L.:

Alfred Hitchcock used the word "McGuffin" to describe the central
"thing"  in a movie  - the document or the address, the bomb or the gun - that
 the story revolves around. Nearly all of us, from before we were born
 until we were placed for adoption, were just such a center of a
 (sometimes fascinating) story. I humbly suggest "McGuffin" as a
 non-offensive, non-intolerant, politically correct, general-use
 alternative to b*****d.

 Where the circumstances surrounding conception are known,
 quite specific euphemisms may be substituted for the B-word. (Or the
 M-word.)
 
 Indeed, more than one euphemism may be applicable to any particular
 case. To the b-mom in my case, for example, I was a Bargaining Chip,
 which the b-father should regard as a Risk Factor.  To the b-father, I
 was a White Elephant, which the b-mom was using as a Guilt Trip.
 
 Select one or more as appropriate:
 
 Placid Ingestation
 Naval Maneuver (or Shore Thing)
 Negligee Case
 Back Seat Striver
 Bargaining Chip
 Party Favor
 Blue Plate Special
 
 Paradise Mislaid
 Experimental Artifact
 White Elephant
 Unforeseen Development
 Providential Implantation
 Passion Fruit
 
 Guilt Trip
 Chagrin D'amour
 Risk Factor
 Stress'ed Event
 Joint Communique`
 Floor Prize