2. An insult. Suggestion that the target is the result of such a pregnancy, due to physical or mental shortcomings.
2. A person you know that is high and acting retarded or unable to control themselves. Not a functioning social user.
3. A person that is addicted and jonesing for some of whatever they are addicted to, unable to obtain what they need they appear to be a crack baby.
Doctor: Actually, on examining these "crack babies," I find that their mothers were almost always alcholics and chain-smokers who were seriously malnourished during pregnancy. Any fetus would be extremely lucky to end up normal in that situation, with or without cocaine.
Interviewer: No, you're not getting the concept. We want to know about the *plague* of *crack babies*. If you won't cooperate we'll just interview someone else.
(true story, paraphrased)