Hyperthyroidism
People ask me a lot of questions, and unfortunately I rarely get a chance to post very many of them here. However, I thought this was a particularly good one, and might be useful to other readers as well, so here we go:
- “I came across your website when I was google searching the words “Ina May” and hyperthyroidism. Reading a bit on your blog, I saw that you did a monstrous report on the condition. I have a ten month old baby girl (my first) and was recently diagnosed with hyperthyroidism (my TSH was .004) but have not yet been to an endocrinologist. My physician put me on atenolol, but I am still breastfeeding so I’m not taking it. Anyway, I was wondering what your report was about, and if you might have any suggestions that you could share. Many thanks in advance.”
Funny that you should ask about this, because we actually had our lecture on thyroid conditions during pregnancy today. My earlier report was on different thryoid conditions which are often seen during primary care of women (not necessarily during pregnancy), although today’s lecture focused only on pregnancy. My first suggestion would be to go to an endocrinologist as soon as possible. There are many different causes of hyperthyroidism, the most common cause being Grave’s Disease, which is an autoimmune disorder caused by thyroid stimulating antibodies. However, there are many other different causes of hyperthyroidism, running the gamut from pituitary tumors (very rare) to iodine-induced hyperthyroidism. This is why you’ll really need an endocrinologist to help figure all of this out; it’s complicated stuff, with many different etiologies.
Another thing to think about is when your symptoms first began. Was it before your pregnancy, during your pregnancy, or has it been only during the postpartum period? If only during the postpartum period, there might be another cause for the hyperthyroidism: postpartum thyroid dysfunction (also called lymphocytic thyroiditis or postpartum thyroiditis), which occurs in about 5-10% of all pregnancies. With this disorder, usually hyperthyroidism develops first, about 2-3 months postpartum, and will continue for up to 4 months postpartum, followed by a hypothyroid phase lasting 1-3 months. In 70-90% of all cases, this will usually resolve spontaneously without treatment, usually within 6 months. However, 10-30% of women with postpartum thyroiditis may have permanent hypothyroidism, so again, it would be a good idea to have an endocrinologist following this in order to determine the true cause of your hyperthyroidism, and whether it will resolve or not.
Treatments for hyperthyroidism usually include either PTU (Propylthiouricil) or Methimazole (Tapazole), both of which interfere with the synthesis of thyroid hormones by preventing iodine uptake. Both of these medications can be used during pregnancy AND are safe for breastfeeding. Atenolol (a beta blocker) was also listed in our lecture as one of the drugs used to help control the severe hypermetabolic symptoms of hyperthyroidism, such as tachycardia (fast pulse), tremors, palpitations and heat intolerance. Beta blockers are actually the treatment of choice for thyroiditis, and are safe to use during pregnancy. There is no contraindications to using beta blockers while breastfeeding. I just visited the website forum of Dr. Thomas Hale, one of the leading experts on pharmacology during breastfeeding, and looked up Atenolol. In this post, as you can see, one woman was concerned about the possibility of a baby having hypoglycemia after breastfeeding from a mother who was taking atenolol, but it seems that while atenolol might cause hypoglycemia in adults, he didn’t think it was present in breastmilk in suffiicient quantities to cause hypoglycemia in an infant:
- I spoke with a Pediatric Cardiologist whom I greatly respect. He assured me that he’s used beta blockers and atenolol many times in pediatric patients and has yet to see hypoglycemia.It is true that in adult diabetics, it may induce hypoglycemia, but I’m reassured that his probably does not occur in infants, particularly from minor exposure via milk.He also told me that infants are apparently less sensitive to beta blockers and that even higher doses are sometimes required to be effective.So I’d look for something else causing hypoglycemia in your infants.
The thread on antihypertensives makes it very clear that beta blockers are fine during breastfeeding, so I think you would be okay taking atenolol and nursing at the same time. Medications in Mother’s Milk might be a really good resource for you.
Other treatment options for hyperthyroidism, if that is indeed what you have (as opposed to postpartum thyroiditis), include radioactive iodine treatment or surgery (partial thyroidectomy), but again, these are options best discussed with your endocriniologist.
I’m including a few resources here in case you want to look any of this stuff up yourself. These were some of the references from my presentation. Hope this helps!
Smeltzer, S., Bare, B. (2000) Metaboloic and Endocrine Function; Assessment and Management of Patient with Endocrine Disorders. Brunner and Suddarth’s Textbook of Medical-Surgical Nursing, Lippincott, Williams and Wilkins: New York.
Reid, J., & Wheeler, S. (2005) Hyperthyroidism: Diagnosis and Treatment. American Family Physician, 72(4): 623-630.
American Association of Clinical Endocrinologists. (2002). Medical Guidelines for Clinical Practice for the Evaluation and Treatment of Hyperthyroidism and Hypothyroidism. Endocrine Practice, 8(6):458-469.
