Congratulations on your pregnancy!
I think that your GP is not fully up to date. If it was me I would phone your midwife straight away and tell her that your GP has refused to increase your thyroxine. Otherwise, or maybe as well, go back to your GP as soon as possible and show him the following from a GP magazine called Pulse. I've included the weblink to this but you need to register if you want to read it - free and easy to do. This is the latest up to date information about the treatment of pregnancy and has been made for doctors to study as part of their CPD.
I've also pasted an exerpt from the BTF website below that, some very up to date informationabout pregnancy.
I hope these help, do let us know how you get on.
Key questions on thyroid disease (1.5 CPD hours)
26 May 10
10 And what about hypothyroidism in pregnant women?
Untreated maternal hypothyroidism results in neuropsychological damage to the offspring. Patients with hypothyroidism who become pregnant need to have the dose of levothyroxine increased on average by 50µg daily in order to maintain normal serum TSH concentrations.
The advice to patients with established hypothyroidism is that they should increase their dose of levothyroxine by 25µg daily as soon as pregnancy is confirmed and make an appointment for thyroid function tests to be measured some two weeks later. The aim is to achieve a free T4 concentration of 16-20pmol/l.
Further measurement of serum free T4 and TSH should be made six weeks later and again in the middle of the second and third trimesters.
The pre-pregnancy dose of levothyroxine can be restored four weeks after delivery by which time the increased concentrations of thyroxine binding globulin will have returned to normal. It’s not clear whether this meticulous care is necessary and it may well be that any thyroxine therapy in the hypothyroid mother will allow normal foetal development.
Dr Tony Toft is consultant physician and endocrinologist at the Royal Infirmary of Edinburgh, and a former president of the Royal College of Physicians of Edinburgh and of the British Thyroid Association"
The aim of this project is to get out some important messages that all women with a history of thyroid disease need to know about: 1) increasing the dosage of thyroxine by approximately 25-50 mcg in women with existing hypothyroidism; 2) diagnosis and treatment of postpartum thyroiditis; and 3) the risks to mother and baby if a thyroid disorder is left untreated during pregnancy (miscarriage, pre-eclampsia, and placenta abruptio). The Pregnancy Project group met in February to outline strategies to publicise the message of thyroid disorder and pregnancy.
We have produced a TiP (Thyroid in Pregnancy) card that we will be giving out at conferences, meetings and mailers.
This little information card, the size of a credit card, contains brief but clear information about these points. If you would us to send you some TiP cards, so you can pass them on to friends and family, please contact us at email@example.com. You will be helping us to get our message out. And you can give us your feedback too - send an email to the address above.
Articles about pregnancy and thyroid have been accepted for publication in two midwifery journals and an article on thyroid, pregnancy and the risks has been accepted for publication in the DoH Children, Families and Maternity e-bulletin. We also highlighted pregnancy and thyroid disorders at the British Endocrine Society conference in March and will be doing so at the Royal College of General Practitioners' conference in October."