They test for any illegal drug use, or any other drugs that may be a hazard for the infant. However, they do not always drug test when you give birth, as it is not a routine. Still, more states are...
A previous answerer wrote xanax, valium, mushrooms, acid. Any of these can be found with thorough testing. If you are subject to drug testing, just don't do drugs.
Ice is a term for methamphetamines, usually crystal meth. It's a strong and highly-addictive stimulant that can and often does cause serious health issues in users.