On Methimazole, TSH decreasing

Hi there.  My name is Sheena and I was dx with Graves last year. At the time my TSH was .01.  I was put on Methimazole 20mg/day and my TSH when up over the months of tx and now I am taking 5mg/day.  I get my TSH checked every 6 weeks.  Last week I got my results and my TSH had gone from 3.3 to 1.06 and my dosage hasn't been changed for at least 4 months.  Should'nt my TSH be going back up?  I've been taking meds for a year now.  I was just hoping to be in remission after a year so I can stop taking the meds.  I love being a mother and I'd like to have one more child.  Thanks for taking the time to read my question

[Mark Lupo, M.D.]

TSH going a bit lower is suggestive but not conclusive that remission is less likely.  At this point, I often check a TSI and compare to initial TSI  (if tested, aka TSH-Receptor Ab) -- if still high, less chance remission.  If cannot wean off tapaole (going to 2.5mg/day to see response may be worth a try), then options include using PTU (instead of tapazole) and going ahead with pregnancy OR going to I-131.  Remember - only about 40% of patients achieve remission with anti-thyroid drugs.  IF I-131, then wait at least 6 months before trying to conceive.