Baby Rabies
Apparently "baby rabies" is one of many derogatory terms used to indicate "the condition of desiring to have a child". The term is most often used by some (not all) childfree folks, which is not the same as childless. "Breeders" is another, more familiar term. One might run across the term in some of the online pro-choice forums, where artificial birth control, particularly the birth control pill and other drugs that may have an abortifacient effect, are referred to simply as medication. One might also note how television ads for birth control are remarkably similar to television ads for Herpes treatments. Children are a great responsibility, but when a society equates children with disease, I just don't see how much longer it can survive. That's just my observation.
In an effort to cover my bases here, I want to add that I also know the term has been used to refer specifically to an inordinate desire to have a baby, as in, a desire for the wrong reasons, lacking a sense of responsibility, etc... But I have seen it used generally (primarily in pro-choice circles, as I mentioned) to refer to any strong inclination toward motherhood, something that is quite natural, and should never be associated with a disease, as though it were some sort of unnatural affliction.