I'm on 75mcg Levothyroxine a day, diagnosed about 10mths ago when my son was 7mths old. I'm only 5weeks pregnant but guidelines state that Levothyroxine should be increased by 25-50mcg to ensure minimal adverse effects on fetal development. Can anyone offer any further advice on this? I've spoken to two doctors at my clinic and neither have suggested increasing my dose or requested blood tests. Fortunately I had some blood tests outstanding so should get results next week.