Re: terrified

I would never do any medical action based on a single test. See my post on "tests" in a separate topic above. It appears to me that these infant T4 etc., tests are prone to false positives and false negatives. If the quality of services I've seen in all other aspects of "american" life are any indication, I'd say the medical techs aren't immune themselves from incompetency. Remember, licensed physicians cause over 750,000 iatrogenic deaths annually in the US alone, and they're supposed to know what the h377 they're doing. If the kid had a false test result and you give it synthroid, that could create a problem where one didn't exist in the first place.

Back when I worked in the lab, if we got a result that was out of spec., we'd re-run it. If it was still out of spec, we'd request a re-sample of fresh specimen.
If it still came out of spec, then we'd run a calibration standard on the instrument, one before the actual sample and one after running it.

Are you being told to take a medical action for an infant based on a single test result ?

I've noticed that fear is often used as a tool.