Pregnancy and Thyroid

Is thyroid important in pregnancy?

Yes, it is. A normal thyroid is needed for regular egg production. Very low thyroid in man also can effect sperm production. This is the reason why thyroid function test is included in the investigation of infertility.

Again a normal thyroid state is needed for maintenance and continuation of pregnancy. The incidence of miscarriage is high with low or high thyroid.

How do we treat under active thyroid in pregnancy?

Treatment is actually very simple. If diagnosed to have under-active thyroid, treatment should be started immediately. Mother’s under-active thyroid may affect the baby in the tummy in different ways. This is a sort of natural treatment, replacing the deficient hormone. We now prepare in the laboratory same thyroid hormone (same chemical nature) that is produced by our thyroid gland, so the chance of reaction or not tolerating is not there. You need to take the tablet regularly in empty stomach and in the correct dose.

Remember iron and calcium tablet do not allow thyroid tablet to get absorbed from the stomach. You will be taking are iron and calcium tablet in pregnancy, there should be a gap of four hours between thyroid tablet and iron/calcium.

What is the correct dose?

There is no correct dose; we need to give you the dose your body needs. Remember, you dose of thyroid medicine will go up in pregnancy, because for the growing baby the demand is more. So, we need blood check in pregnancy a bit more frequently.

Treatment of Overactive Thyroid in pregnancy

Treatment of overactive thyroid is always with tablet that suppresses the thyroid gland (Carbimazole and Propylthiouracil). Radioiodine is NOT to be given in pregnancy. If we can not manage with tablets, we might have to proceed to surgery, that is taking the thyroid gland out. This is actually very rare.

Can I plan pregnancy when I am on thyroxine tablet?

Safely you can. As we have told, the structure of the thyroid hormone in our body and that of the thyroid tablet is the same, so there is no chance of baby getting problem of any sort. Also, another information of comfort is thyroid hormone does not cross the placenta meaning it does not reach baby. Commonly, pregnant ladies stop treatment because of the fear but stopping can be very harmful and can end up with termination of the pregnancy. The dose requirement of thyroid tablet in pregnancy goes up simply because demand increases. Hence it is recommended to have thyroid tests done at least three-times during pregnancy. Also a fine tuning of the dose is required in pregnancy for normal growth of the baby.

Can I plan pregnancy with overactive thyroid?

You can safely plan for pregnancy if you have overactive thyroid but it is best to sort out thyroid problem before conception if possible. If you have received radioactive iodine, you should not conceive within four months of treatment. We start medical treatment with tablet if you have been diagnosed to have overactive thyroid for the first time in pregnancy and control the thyroid function. This time you may require frequent testing of the blood, may be once a month. Also we monitor baby’s growth carefully by ultrasound. Baby getting a problem of thyroid if mother has overactive thyroid is rare and we can not predict. So it is better not get worried and follow the suggestion of your Obstetrician and Endocrinologist.