As far as I know, there are no laws in the united states that say it is unlawful for babies to be born with THC in their system, so I don't think you need to worry about jail.

As for smoking while pregnant, this is usually frowned upon, it can cause problems for the baby. What those problems are, I am not sure, im no doctor. Having admitted that, I think it is best to talk to your doctor about your apparent marijuana withdrawals. I had smoked every day for at least the last 5 years, and have recently stopped, and I never experienced any kind of withdrawal type sickness, nor has any one I have ever known.

As far as going to jail or having your baby taken from you, I wouldn't worry much about that. That really only becomes a concern if you actually get arrested for possession, or a social services agency believes you are neglecting your child because you are out getting high all the time.

Hope this helps