LB, congrats on your pregnancy! Also on your sobriety.
I am begining to sound like an advocate for Methadone anonymous here but if you enter a google search you will find it and it is a great place for just this kind of thing. They are all great folks and have been exactly where you are and many are pregnant now or have had treatment during several pregnancies.
I cant urge you enough to go there and also look up any local chapter or affiliate as support is a major major part of having a successful recovery and that is essential to you and your baby.
There is absolutely NO pain med that is 100 percent safe for a unborn child and everything that you take passes thru your baby.
They can use past experiences from folks who have used pain meds of a variety during pregnancy but they as far as I have found dont have a controlled study,the insurance for something like that would be astounding! Not alot of Moms to be are going to enroll in drug studies that intentionally put their fetus at risk.
I also here and please dont take this wrong or out of hand as you obviously are concerned for your baby or you wouldnt have come here,make sure all of your treating Docs are aware of all aspects of your addiction and be straight up honest as it may mean the difference between a healthy baby and not.
The best outcomes for addicts that become pregnant occur when the Mom is honest and upfront about how much she is doing and what all she is doing.
I want to add here this also can save yourself alot of heartache and battle with childrens services as well. They will take a backseat to your addiction treatment and monitor you from afar if you have been upfront from the get go and you sought out help with the addiction and didnt try to cover it up. They will support you in everyway possible to assure that you stay clean during and after the baby is born.
They are not as compassionate and understanding if you do not come clean with all Docs involved.
Most every state offers free methadone or Sub-X treatment to pregnant ladies thru the entire pregnancy and offer a detox off afterwards for baby and yourself,a nice place to get off and stay off and this is beneficial to you and the baby for years to come.
Your baby will also have to be detoxed after it is born from either the methadone or Sub-x as both of these enter the baby thru you but it is better then giving birth to a baby addicted and untreated for that addiction.
I urge you to look up the Methadone anonymous forum for their help and their assistance as they will have so many more answers then we have here.
I am not in anyway trying to turn you away from here but all of us have chronic pain issues and are not as familiar with the issues of addiction and use of Sub_x as it as not generaly used in chronic pain like methadone is.
We will always be glad to respond in the best way we can here but you deserve the best and correct answers you can get.
Good luck to you and your baby and I hope all goes well for you both.