Your wife needs to be tested every month from now until the end of
pregnancy. It is normal that thyroid meds need to be increased
during pregnancy. Ask the doctor to test TSH, FT3 and FT4. The T4 should also be at the top of the reference range (if it's not the meds need to be increased), regardless of whether TSH is high or low.
Anyway, I think your baby should be fine. The level was fine at week 1 sot that's a very good start. 5.