From flesh + loaf. Apparently derived from "pinching off a flesh loaf" (attested in 1999), which likens childbirth to a bowel movement (pinch a loaf being slang for "to defecate").
fleshloaf (plural fleshloaves)
- (slang, derogatory) A baby.
2001 October 21, JD Kidkill [username], “Re: Stupid Breeder LTTE”, in alt.support.childfree, Usenet:
- Elderly don't bug me, however loud drunken adults bother me as much as screaming fleshloaves.