Low TSH and normal T4

[Mmcauley]

I am 12 weeks pregnant and have been referred to a maternal fetal medicine (high risk) doctor by my regular OBGYN due to a very low TSH level. The first free T4 test showed abnormally high 4.1, TSH was .14; 1.5 weeks later, the free T4 showed in the normal range at 1.18 but the TSH continues to drop at .029 on this second blood test just done yesterday. This all seems to me to be onset by preganancy as at my last physical in Feb of this year, my non-pregnant levels were normal with TSH at 1.610 and Free T4 at 1.25. Could these levels just be thrown off by pregnancy hormones like HCG, etc.? Both of my doctors do not seem to be reacting to quickly to any of this. I am the one pushing to get some resolution on this and determine if I need to be concerned if these continued low TSH levels could affect the fetus negatively. I am 35 and this is my first successful pregnancy w/ no known prior thyroid complications. I had an ectopic pregnancy last fall so am trying to be overly cautious to take the right course of action / treatment if neccessary. Please help!! I'm most worried I could actually have this "Graves Disease" I read about and am praying this is not the case. Could you have Graves and still have a normal free T4 level? I have had lots of anxiety / nervousness / dry and sensitive eyes / heart palpitations, but aren't these all normal pregancy symptoms especially early on at 12 weeks when there is so much going on the body? Is it common to have low TSH and normal T4 in early pregnancy?? Would appreciate any medical feedback.

[redheadaussie]

You don't mention if you are taking any thyroid medication to start with. Many women have to have their levels adjusted throughout the pregnancy, as the body does go through a very intense time to keep up with the changes in the body.
  No, anxiety etc as you mention is not normal in early pregnancy. You are becoming hyperthyroid and that is giving you the symptoms you mention.
  If you aren't on medication already, you need to be! Really push with your high risk doctor to get you on some thyroid medication as soon as possible.
  Grave's Disease tends to have continually high T4, so it is more likely you are just hyperthyroid at this stage.
Good luck.!

[Mmcauley]

I have never had a thyroid condition that I know of, so I am not on any thyroid medication. Thanks for your response!