Quoting Brookelynbaby:" I have been wondering this myself! I have been very honest with my OBGYN tho... I think if they do find ... [snip!] ... I was very honest because this is my un born child, and wish to give him the best most healthy start in life anyhow. "
I'm honestly not worried about it. My neighbor was the one who told me about it and said it can show if you've used any illicit substance at any point in your pregnancy. If the blood is constantly flowing through the cord, then I don't see it as possible. The only thing I can figure is maybe they test the cord tissue or something?
From my experience, if you test negative and have made your OB aware of the situation little will be done. I was honest with my OB with my forst child about my prenatal drug use and all CPS did was a quick home study to confirm that I was no longer actively abusing opiates.