Through not being able to conceive naturally I discovered amongst other issues (PSO and low sperm count) That I had an under active thyroid TSH 13. My doctor started me on liothyronine and got my TSH down to 3.4 with a 75g dose which is within guidelines. However the ivf clinic said we could not do the egg transfer unless my TSH was under 2.5 as it will cause a miscarriage. My doctor upped my dose to 100g and my TSH dropped it within 2 weeks to 1.7, it then continued to drop and went to 0.13 which was causing my heart to race. So my doctor told me to alternate between a dose of 100 and 75 everyday. While all this was happening we had the egg transfer and I found out it worked and I'm now 3 weeks pregnant. I just had another blood test and my doctor just rang me very concerned as my TSH has shot up to 10! I had told her the ivf clinic said I needed to be under 2.5. She has told me I can increase my dose to 125 or 150 what ever i feel i need ??!! She is not a ferity expert so I thought I'll ring the ivf clinic and ask them what my TSH level needs to be when pregnant and is it normal for my TSH to have shot up like that. They won't help me at all, they now won't even confirm that it needs to still be under 2.5 just keep saying speak to my doctor. I so worried I'm going to harm our baby. I started on 125g this morning and booked in for a blood test in 2 weeks. I'm scare 150 will be too much but getting from 10 to 2.5 is a big jump.