I am 37 and have had an underactive thyroid for 10 years. I had a miscarriage at 18 weeks in February 2011. My thyroid was not checked until week 12 of my pregnancy and at 15 weeks my dose was upped from 125mcg daily to 175mcg. I was later told that my baby had died between 12-13 weeks and my thyroid should have been tested far sooner. I want to try for another baby as soon as possible. My thyroid has taken a while to stabalise after the miscarriage. My question is how often should my thyroid be tested during a future pregnancy?