Babies are usually only tested at birth if the mother is a suspected user or if the mother has had more than one positive drug test result for THC during her pregnancy. Don't believe all of the rumors about smoking pot. Most people have been blindly led to believe that marijuana is a terrible drug that leads to harder and more addictive substances but this is rarely true. Occasional usage of marijuana has actually proved beneficial in relieving morning sickness in pregnant women. This is the same concept as giving THC to chemotherapy patients that suffer from nausea and appetite loss. If you know that you are going to be tested then stop using at least 3 months before your due date. Just remember that THC is stored in fat cells so the more fat you have, the longer it will take to clean your system. Please do not use commercialized cleansing products to rid your system if you are pregnant because these products are not designed for those individuals.