normal tsh low free T4 in 21 weeks pregnancy

[cloudhearter]

I am 21 weeks pregnant. I am tested to be Hashimoto's thyroiditis for more than 2 years. But I have not take any pills as I only got a high anti-tg and nothing more.
But from last month, I was tested to be with normal TSH, 1.76uIU/ml. lower FT4 10.91pmol/l (range 12-22pmol/l)
Do I need to take pills? My doctor suggested to have euthyrox 25ug/d, but will this influence my baby?

[cloudhearter]

Thanks, I have tested free T3 and it was normal
my test results was
TPO  0  IU/ml range(0-5.61)
Anti-Tg 17.92 IU/ml (0-4.11)
TSH  1.760 uIU/ml (0.27-4.20)
FT4 10.91 pmol/l (12-22)
FT3 3.89 pmol/l (3.1-6.8)
TT3 2.20 pmol/l (1.3-3.1)
TT4 118.4 nmol/l (66-181)
I am diagnosed as Hashimoto's 2-3 years ago and always with high Anti-Tg. Free T3 is OK. It is only Free T4 is low. Do I need to take Euthyrox then?

[Barb135]

I don't understand about the high anti-tg.  That's the antibody that was used to diagnose Hashimoto's?  Thyroid replacement pills should not cause that to be raised; those are the antibodies that are destroying your thyroid.

Your doctor is correct that you should be on thyroid medication, with an FT4 of only 10.91.  You really need to have an FT3 test done, also.  FT4 is a storage hormone and must be converted to the active FT3 prior to use by the cells.

Adequate thyroid hormones are essential for the growth and development of a fetus, so yes, the Euthyrox will influence your baby, but in a good way.