As far as addiction for the baby at birth...no....you may need to get him to get tested for any spreadable diseases if he uses a needle....having a dad who uses heroin if he does not quit, would have its consequences in the longer term scope of things
There are of course legal issues if he gets busted. As long as you are not using, there will not be any drugs getting to the baby. I do hope you know that this is a serious situation if you plan on raising a baby in a drug environment!