Information for women with thyroid disease

You have been diagnosed with thyroid disease. If you wish to become pregnant in the future we would advise the following:

• Before you plan to become pregnant please have your thyroid function tested. Your GP should aim for a TSH level of 2.5mU/L or less (if on thyroxine) or within the normal range (if not on thyroxine).
• If you miss a period, perform a pregnancy test. If this is positive and you are on thyroxine immediately increase your dose. You may choose either of these two ways to do this (but not both).

1. Take an extra 25micrograms of thyroxine every day.

OR

1. Double your daily dose of thyroxine, but only on two days per week. For example:

• If you have a positive pregnancy test, please make an appointment with your GP as soon as possible for a thyroid blood test. Your GP should aim for a TSH level of 2.5mU/L or less.
• You should also arrange to be referred to the thyroid clinic by your GP so that we can monitor your thyroid function during pregnancy.
• An antibody level (called an anti-TSH receptor antibody) should be checked in the later part of pregnancy. Your obstetrician or endocrine/thyroid physician will do this, but please remind them that you have been advised to have this done.

Please keep this leaflet in a safe place and give a copy to your GP.