hyperthyroidism Archives - Hormones Matter

Thyroid Disease and Testing During Pregnancy

Published on May 17, 2020

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One in five women of reproductive age suffers from some form of thyroid disease, mostly hypothyroidism (Gharib et al. 2005; Hollowell et al. 2002). In adult women, 95% of clinical hypothyroidism results from primary disease of the thyroid gland, generally, the autoimmune condition Hashimoto thyroiditis (Wartofsky et al., 2006). Autoimmune thyroid disease is also common among women with Type 1 diabetes mellitus, Sjogren syndrome, Addison disease, or pernicious anemia. Up to 25% of patients with Type 1 diabetes will develop postpartum thyroid disease (Alvarez-Marfany et al., 1994).

Hypothyroidism During Pregnancy

What happens when a woman with untreated thyroid disease gets pregnant? Depending upon the diagnostic criteria, hypothyroidism affects 0.3% (Casey & Leveno, 2006) to 5% (Gharib et al. 2005) of pregnancies. The symptoms are vague and are similar to other pregnancy concerns making diagnoses based on clinical symptoms alone difficult. Hypothyroid symptoms include fatigue, constipation, cold intolerance, muscle cramps, insomnia, weight gain, carpal tunnel syndrome, hair loss, voice changes, and slowed thinking.

The consequences of undiagnosed hypothyroidism during pregnancy are significant. Hypothyroidism is associated with premature birth, pre-eclampsia, abruption, low birth weight (LBW), postpartum hemorrhage, and impaired neuropsychological development in childhood (Burman, 2009). Research found that fetal loss was higher in untreated hypothyroid women (29%) vs hypothyroid women taking levothyroxine (6%), highlighting the need for early detection (Hallengren 2009).

Hyperthyroidism During Pregnancy

Hyperthyroidism, the result of an excess of thyroid hormones, complicates less than 1% of pregnancies (ACOG Practice Bulletin, 2002). Symptoms of hyperthyroidism are uncommon in normal pregnancy and thus somewhat easier to identify clinically. Maternal symptoms include weight loss or failed weight gain despite increased dietary intake, resting tachycardia, hypertension, tremor, eye stare, eyelid lag, proptosis, and thyroid enlargement or nodule.

Graves’ disease, an autoimmune disorder occurring in 0.5% of the population, accounts for more than 90% of the hyperthyroidism associated with pregnancy. Complications associated with undiagnosed or poorly managed hyperthyroidism during pregnancy include pre-term labor, pre-eclampsia and maternal thyroid storm, fetal tachycardia, low birth weight, congenital abnormalities, and stillbirth.

Should Pregnant Women Be Tested for Thyroid Disease?

Yes, but there is little consensus among the major medical associations regarding who, when, and how to test for thyroid function during pregnancy. It is argued that by the time TSH (the gold standard in thyroid diagnostics) becomes hyper-elevated and the clinical symptoms emerge, the damage to fetal neurodevelopment related to insufficient maternal T4 stores, has already been done (Calvo et al. 2002). Emerging evidence suggests that maternal T4 levels may not track directly with elevated TSH levels especially in the first trimester when the demands for maternal T4 are greatest (Morreale de Escobar et al. 2000), making the need for more advanced testing techniques even more important.

Iodine Deficiency and Hypothyroidism: One More Factor to Consider

Complicating matters even further, in iodine-deficient populations, neither TSH, T4 nor T3 denote the underlying deficiency, which as it progresses, inevitably elicits the range of fetal developmental issues and maternal complications associated with hypothyroidism. In the US, approximately 10% of the population is iodine deficient while 50% of Europe is iodine deficient (Zimmerman 2009). In recent years, iodine deficiency has increased in the US in women of reproductive age with 14.9% percent potentially iodine deficient (Hollowell et al. 1998). Similarly, the incidence of congenital hypothyroidism in newborns has also increased in the US over the last two decades (Parks et al. 2010).

Iodine deficiency in women can lead to overt hypothyroidism and consequent anovulation, infertility, gestational hypertension, spontaneous first-trimester abortion, and stillbirth (DeLong et al., 1997). Iodine deficiency is also associated with an increased risk for thyroid carcinoma in animal models and humans (Mellemgaard et al., 1998). In the Bryansk region of Russia, an area of known radioactive I-131 exposure following the Chernobyl disaster, the risk of all types of thyroid cancer was inversely associated with urinary iodine excretion levels (WHO Health Risk Assessment).

What Constitutes Hypothyroidism in Pregnant Women?

In addition to the debate over whether to test pregnant moms routinely for thyroid disease, especially hypothyroid moms, there is much debate regarding what constitutes elevated TSH and whether to include subclinical hypothyroidism (SCH) or mild hypothyroid cases in the testing matrix (Fatourechi 2009; Surks et al. 2004). SCH or mild hypothyroidism is suggested by only slightly elevated TSH concentrations without the normally accompanying changes in T4. Arguments against testing for SCH include the enormous increase in cases; up to 28 million more people could be diagnosed with hypothyroidism, and the conflicting data regarding treatment benefits and disease progression. Moreover, recent evidence suggests significant age and race-based differences in TSH reference ranges across the non-pregnant population complicating diagnoses even further (Surks & Boucai 2010).

Given the dire consequences of untreated thyroid dysfunction during pregnancy, there is a need for more accurate, non-invasive and less expensive thyroid function tests with reference ranges specifically identified for this population of women. Screening for thyroid function in women of reproductive age and in pregnant women could reduce maternal and fetal complications.

Our view on thyroid disorders during pregnancy can be summarized as follows:

Thyroid disease is common in pregnancy.
Hypothyroidism and hyperthyroidism are associated with adverse pregnancy outcomes, and treatment may improve these outcomes.
Untreated hypothyroidism during pregnancy is associated with impaired intellectual development in childhood.
Routine, universal screening for thyroid function in women of reproductive age and in pregnant women could reduce could reduce maternal and fetal complications
Normal reference ranges for thyroid function tests in pregnancy must be established

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Postscript: This article was originally published on February 21, 2012 and updated on July 11, 2014. If I were to rewrite this post now, I would attribute much of the thyroid dysfunction to nutrient deficiencies.

Personal Story: My Thyroid Cancer

by Myrna Wooders

Published on October 18, 2012

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I am a Professor of Economics at Vanderbilt University, VU. I teach and do research. My life is my work and my family. Inside me there is Myrna Holtz, a kid from very humble beginnings on a small farm in rural Alberta, a nerd who loved math puzzles and books but had few of either. Through my own research and through helping others with theirs, I want to contribute to our ability to understand social and economic interaction. I want to be close to my family and now to increase awareness of thyroid cancer and its potential effects. Here is my story.

Some History

In 2008 and 2009 I felt fatigued. My home treadmill rested, unused. In September 2009, my VUMC (VU Med Center) physician palpated my thyroid and detected no problem. Two months later, after a quick swipe of my throat, my gynecologist found that my thyroid was enlarged. We both notified my VUMC physician. He responded (recorded on a VUMC web interface for patients) with, effectively, “See you when you next come in.” I thought, “Oh, that’s good, no problem then. Maybe I had a cold.” But as time progressed, I pressed and pressed again for an appointment with my physician. Finally, in mid-May 2010, after five and a half months, I had an appointment. When my VUMC physician palpated my thyroid, he immediately detected the enlargement and ordered an ultrasound, which I had the same day.

Too Busy to Call: Hearing about my Thyroid Cancer from a Stranger

A few days later, out of the blue, some unknown person phoned to schedule an appointment for me with an endocrinologist and to advise me that I would probably need surgery. What! How could something treated so casually by my VUMC physician be serious? Was it really? If so, why had my physician not seen me sooner? Why had he himself not called? Maybe it was only another surgery opportunity.

My former VU physician always called me “Myrna”. I called him “Dr. Hock”. A trusting patient is like a small child who places her hand in the hand of a benevolent, caring adult. The asymmetry in use of titles reflects this relationship of trust and confidence; the patient wants to be confident that the physician is competent, knowledgeable, and will take care of her. But maybe the asymmetry is designed to keep the physician in a position of unquestioned superiority, above the patient. I started to call my former VUMC physician “Rich”. And he switched, immediately, to “Professor Wooders”. It was almost funny.

With all confidence in VUMC gone – this was the most disturbing but not my first negative experience – I searched for a specialist on the internet and in September 2010 saw Dr. Erik Alexander, at Brigham and Women’s (B&W) in Boston. Erik advised me to have a thyroidectomy and also recommended a surgeon, Dr. Francis Moore, also of B&W. Dr. Moore interviewed me on November 10^th, 2010, and I had a total thyroidectomy on November 11^th. 2010

The Diagnosis: Thyroid Cancer

B&W Pathology reported a tall cell papillary thyroid cancer with extrathyroidal extension (minimal). Not good. Tall cell thyroid cancer has an estimated mortality rate about 16 times that of papillary cancer generally. At least one study proposes that tall cell thyroid cancer can become anaplastic cancer, which is extremely aggressive. “Extrathyrodial extension” means that the cancer has extended beyond the thyroid capsule. With extrathyroidal extension, for individuals over forty-five thyroid cancer becomes Stage III. Whether the extrathyroidal extension occurred during VUMC’s delay is unknown, but I believe it is likely; my VUMC physician was unable to detect the enlargement of my thyroid in September 2009, but detected it immediately in May 2010. I complained to VUMC.

Post-Surgery Treatment

My treatment involved thyroid hormone withdrawal to raise my TSH (thyroid stimulating hormone) and a low-iodine diet lasting some weeks followed by ablation with radioactive iodine (RAI). “Glowies” are not allowed to fly so I had the RAI at VUMC. The endocrinologist at VUMC referred me to his nurse for instructions for the procedure. I was not following the VUMC standard procedure of injection of Thyrogen (a form of TSH) to raise TSH but instead hormone withdrawal. The instructions for my procedure were somewhat garbled. I sought and obtained clarification, but still it was anxiety-provoking.

In January 2011, three men in hospital garb brought my RAI pill into a small, cold room at VUMC where I had been waiting on a small, cold hard chair. Might they be like three co-authors, each of whom relies on the other two to catch any mistakes? Might something else have been garbled? But I was at VUMC to swallow the pill so I swallowed the pill.

A few days after swallowing the pill, standard procedure is to have a whole body scan to see where the RAI was soaked up. I lie in a cold machine in a cold room, while in the adjoining small room with a glass window and open door several hospital personal watched monitors, laughed and giggled. Was it funny? Most important, though, the RAI was soaked up where it was supposed to be – in the thyroid bed.

Surgery and Treatment Side Effects: Hyperthyoidism

After my surgery I had a sore throat. But the frequent sensation of clutching around my neck, the heaviness in my chest, my sometimes racing heart, and extreme fatigue seemed to only get worse. Last year, 2011, was a very bad year. I had MRIs, electrocardiograms, nuclear stress electrocardiograms, nuclear perfusion tests, CT scans with contrast, and blood tests for everything. But no explanations of my symptoms were offered. The symptoms intensified.

It now seems that I was suffering effects of hyperthyroidism. To suppress the activity of any remaining thyroid cells, thyroid cancer patients are prescribed high levels of levothyroxine (thyroid hormone). Individuals react differently to hyperthyroidism. I had multiple symptoms – fatigue, anxiety, palpitations, and an atrial fibrillation. (At the time of my atrial fibrillation I was in Sydney. My wonderful daughter-in-law came to the hospital. I was so glad that she was there to keep watch. By the way, there everyone – doctors, paramedics, nurses – called each other by their first names. I was “Mrs. Wooders”.) It might have helped to know that my symptoms were those of hyperthyroidism, not of the return of cancer. See http://www.myrnacatharsis.com/what-it-is-like/ for more of the story.

All Clear

My first post-thyroidectomy exam was on August 20^th, 2011 at B&W. There was no observable evidence of cancer. It was wonderful. The sun shone, the trees glistened, the streets of Boston were filled with happy, smiling people.

Last March we reduced my levothyroxine. And, as time passes, it becomes less and less likely that I will have any recurrence. Back in rural Alberta, I had learned to “never let them see you cry” so I tried to keep my thyroid cancer private. This spring I decided to go public; I let my colleagues in VU Economics know in an email and via my website: Myrna’s Catharsis. I found the Thyca website (Thyroid Cancer Survivors Association) and learned that my experience with extreme hyperthyroidism had been shared by others. See: What it is Like.)

In the spring of 2012, my tests looked very fine. My treadmill squawked a bit with its first use this summer, but now runs smoothly! Except for emotional scarring, I feel back to normal. If I have to increase my levothyroxine again, I will recognize symptoms of hyperthyroidism. If I have a recurrence, I think that it will not be for some years; I am hoping for forty. It may be useful for other thyroid cancer patients to know the symptoms that may occur as a result of their treatment, for persons in positions of power over others to better understand that thyroid cancer survivors may be hyper (or hypo) thyroid. And for physicians to recognize that not all thyroid cancers are slow growing so a patient with an enlarged thyroid should not be ignored.

Some fantastic reference books that I found along my journey:

Kenneth Ain, A specialist in thyroid cancer, author, with Sara Rosenthal, of The Complete Thyroid Handbook, which includes a discussion of various levels of care, including “standard community care” – what one might expect of their local GP.

Another excellent, more technical and specialized book is Thyroid Cancer: A Patient’s Guide By D. Van Nostrand, G. Bloom, L. Wartofsky

This article was posted previously on ThyroidChange and re-posted with permission.

From Myrna Wooders (www.myrnacatharsis.com)

hyperthyroidism