Hi XXXXXXX

Thanks for posting your query.

During pregnancy two hormones are produced; these are hCG and estrogen which cause increased thyroid hormone levels in the blood.

Made by the placenta, hCG is similar to TSH and mildly stimulates the thyroid to produce more thyroid hormone. Increased estrogen produces higher levels of thyroid-binding globulin, a protein that transports thyroid hormone in the blood.

Moreover it can be due to subclinical hypothyroidism which is a mild form of hypothyroidism that has no apparent symptoms. Investigations show high levels of TSH and normal free T4 levels and hence it is advisable to initiate treatment in such cases also.

Although you had normal TSH levels prior to pregnancy, you have raised TSH levels now in pregnancy. During the first trimester, the fetus depends on the mother’s supply of thyroid hormone but after 10-12 weeks it starts producing its own thyroid hormone.

We cannot predict at the moment whether you have had the tests late because you are 17 weeks pregnant and by this time the baby has started producing his/her own thyroid hormone.

However get regular ante natal checkups done to rule out or detect early complications of hypothyroidism. These include anemia, low birth weight and pre eclampsia. So get your hemoglobin count, ultrasounds and BP monitored at regular intervals.

Continue with the synthetic thyroid hormone like Eltroxin and keep a watch on above mentioned parameters. Also get the tests repeated every 6-8 weeks to keep an eye on the levels and hence adjust the dose accordingly.

Hope this answers your query. If you have additional questions or follow up queries then please do not hesitate in writing to us. I will be happy to answer your queries.

Wishing you good health.

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Hi XXXXXXX

The risk of the baby having hypothyroidism is more if the mother remains undiagnosed of hypothyrodism during pregnancy or remains untreated or under-treated.

Remember that the dose of thyroid supplements increase by approximately 50% during the pregnancy and hence the dose needs to be 50% more compared to the non-pregnant adult.

If the development of the baby is fine till now, I assume everything should be fine. The best way to know the growth of the baby is by ultrasound only and there's no other method to know about the neurological development of the growing fetus.

You should not take iron as that enhances the possibility of iron toxicity in beta-thalassemia trait.

It's good that you have been advised TPO antibodies as that gives us a good idea about the underlying auto-immune damage to the thyroid gland. The presence of TPO antibodies in high titer is indicative of a definitive need for the thyroid supplementation.

I sincerely hope that helps.

Wishing you good health.

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Hello XXXXXXX

Thanks for writing back with the reports.

It is good that the TPO antibodies have come out negative. Basically TPO antibodies represent tissue destruction, such as Hashimoto's disease and Graves disease and may also indicate chances of post partum thyroiditis. But since it is negative, hence these conditions are ruled out.

However your TSH levels are high and not borderline high. So you should continue with Eltroxin and get your TSH levels checked after a few weeks. TSH levels need to be checked continuously throughout pregnancy and after delivery for a few weeks. The dose of Eltroxin can be adjusted accordingly.

Hope this helps you.

Wishing you good health.

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