Hi. I have thyroid before pregnant .before my pregnant my thyroid level is 2.0.whenever I am pregnant thyroid level is increased to 5.50.then I am using tretinoin 62. 5 mcg.yesterday I checked my thyroid level is 5.20.I heard that 1 trimester pregnant lady should have below 2.0.how much throdinum dosage should be use to reduce my thyroid level. Right now I'm using 62. 5 mcg.