Postpartum thyroiditis: long-term follow-up

Assessment and treatment of thyroid disorders in pregnancy and the postpartum period

Thyroid disorders are prevalent in pregnant women. Furthermore, thyroid hormone has a critical role in fetal development and thyroid dysfunction can adversely affect obstetric outcomes. Thus, the appropriate management of hyperthyroidism, most commonly caused by Graves disease, and hypothyroidism, which in iodine sufficient regions is most commonly caused by Hashimoto thyroiditis, in pregnancy is important for the health of both pregnant women and their offspring. Gestational transient thyrotoxicosis can also occur during pregnancy and should be differentiated from Graves disease. Effects of thyroid autoimmunity and subclinical hypothyroidism in pregnancy remain controversial. Iodine deficiency is the leading cause of hypothyroidism worldwide. Despite global efforts to eradicate iodine deficiency disorders, pregnant women remain at risk of iodine deficiency due to increased iodine requirements during gestation. The incidence of thyroid cancer is increasing worldwide, including in young adults. As such, the diagnosis of thyroid nodules or thyroid cancer during pregnancy is becoming more frequent. The evaluation and management of thyroid nodules and thyroid cancer in pregnancy pose a particular challenge. Postpartum thyroiditis can occur up to 1 year after delivery and must be differentiated from other forms of thyroid dysfunction, as treatment differs. This Review provides current evidence and recommendations for the evaluation and management of thyroid disorders in pregnancy and in the postpartum period.

Thyroid Disease in Pregnancy: ACOG Practice Bulletin, Number 223

Both thyrotoxicosis and hypothyroidism are associated with adverse pregnancy outcomes. There also is concern about the effect of overt maternal thyroid disease on fetal development. In addition, medications that affect the maternal thyroid gland can cross the placenta and affect the fetal thyroid gland. This document reviews the thyroid-related pathophysiologic changes that occur during pregnancy and the effects of overt and subclinical maternal thyroid disease on maternal and fetal outcomes. This Practice Bulletin has been updated with information on the diagnosis and the management of thyroid disease in pregnant women and includes a new clinical algorithm on management of thyroid disease in pregnancy.

Postpartum Follow-Up of Patients with Subclinical Hypothyroidism During Pregnancy

Background: Subclinical hypothyroidism (SCH) in pregnancy is associated with adverse pregnancy and perinatal outcomes. However, few studies have investigated the evolution of postpartum thyroid function in these women. This study aimed to determine the postpartum outcomes of SCH during pregnancy and the clinical and biochemical factors related to the evolution of long-term hypothyroidism. Methods: A total of 393 women diagnosed with SCH during pregnancy (defined as thyrotropin [TSH] >4.0 μIU/mL with normal free thyroxine levels according to the 2017 American Thyroid Association guidelines) were prospectively followed up after delivery. Among them, 216 underwent long-term follow-up [median (interquartile range) follow-up time: 11 (7-19) months] postpartum. The clinical and biochemical characteristics of the women with long-term postpartum hypothyroidism and euthyroidism were compared. Linear mixed model (LMM) was used to explore the risk factors for longitudinal changes of TSH, and logistic regression analysis was employed to identify the independent predictors of long-term postpartum hypothyroidism. Results: The probability of long-term hypothyroidism after delivery in SCH during pregnancy was 38.9%. Among the subjects with normal thyroid function 6-week postpartum, 28.2% developed hypothyroidism during long-term follow-up. The LMM showed that gestational age at the time of SCH diagnosis (estimate: -0.018, p = 0.004) and thyroid peroxidase antibodies (TPOAb) (estimate: 0.001, p = 0.020) were significantly associated with longitudinal changes of TSH. The logistic regression model showed that TPOAb positive both during pregnancy and six-week postpartum was a risk factor for long-term hypothyroidism after delivery (odds ratio = 4.686 [95% confidence interval 1.242 to 17.680], p = 0.023). Conclusions: More than one-third of patients with SCH during pregnancy had persistent hypothyroidism after delivery. We recommend that patients with TPOAb positive both during pregnancy and six-week postpartum undergo close follow-up to detect persistent hypothyroidism, especially before the next pregnancy.

[Thyroiditis: What's new in 2019?]

Thyroiditis is a frequent and mostly benign disease that can sometimes disrupt the thyroid balance. Their diagnosis, as well as their aetiology, is a necessary step in the management of the patients. Painful thyroiditis includes acute thyroiditis of infectious origin and subacute thyroiditis. The first one can be treated by antibiotics or antifungals depending on the germ found. The second one will be treated with non-steroidal anti-inflammatory drugs or corticosteroids. In cases of Hashimoto's thyroiditis with overt hypothyroidism, replacement therapy with L-thyroxine will be adapted to the TSH level. As amiodarone treatment provides dysthyroidism, the thyroid status should be monitored regularly. Hypothyroidism will be treated using thyroid replacement therapy. Hyperthyroidism imposes a stop of amiodarone when it is possible. Treatment with synthetic antithyroid drugs (propyl-thio-uracil) or corticosteroids could be used whether there is an underlying thyroid disease or not. Immunotherapies with anti-PD-1/PDL1 or anti-CTLA-4 can also provide dysthyroidism. A monitoring of the thyroid assessment needs to be done in these patients, even if there are no clinical signs, which are not very specific in this context. The treatment of hypothyroidism will be based on thyroid replacement therapy according to the TSH level and the presence or absence of anti-TPO antibodies. Treatment of symptomatic hyperthyroidism may involve a prescription of beta-blockers, or synthetic antithyroid drugs in case of positive anti-TSH receptor antibodies. In all cases, it is desirable to contact an endocrinologist to confirm the diagnosis hypothesis and to decide on a suitable treatment.

Changes suggestive of post-partum thyroiditis in women with established hypothyroidism: incidence and predictors

OBJECTIVE

Post-partum thyroiditis (PPT) is a common phenomenon in the general population. To date there have been few studies examining the incidence of PPT in women with hypothyroidism antedating pregnancy. This study aimed to assess the incidence and potential predictors of PPT in women with treated hypothyroidism antedating pregnancy.

DESIGN

Retrospective cohort study.

PATIENTS AND METHODS

We compiled a cohort of 97 women with previous hypothyroidism antedating pregnancy seen in the Endocrinology in Pregnancy clinic from 1999 to 2011, collecting data on thyroid function, antibodies and levothyroxine doses post-partum. The incidence of PPT and its predictors were analysed.

RESULTS

A total of 66 (68%) women had fluctuations in thyroid function consistent with PPT. Of these, 22 (33%) had a hyperthyroid phase alone, 22 (33%) had a hypothyroid phase alone and 22 (33%) had both a hyper and hypo phase. The majority of women had their dose of thyroid medication adjusted during the PPT episode. Women who were on a full dose of thyroxine post-partum were significantly less likely to have a hypothyroid phase. In multivariable analysis, the only predictor of PPT was the presence of thyroid antibodies, with 83% of antibody positive women having PPT compared to 44% of antibody negative women (P = 0·0001).

CONCLUSIONS

In our cohort, 2/3 of women had fluctuations in thyroid function consistent with PPT and most required adjustment of their thyroid dose. Women with hypothyroidism antedating pregnancy are at high risk for PPT and should be closely monitored during the first year post-partum.

Subacute, silent, and postpartum thyroiditis

Subacute, silent, and postpartum thyroiditis are temporary forms of thyroid dysfunction caused by thyroid gland inflammation. They classically present with a triphasic course: a brief period of thyrotoxicosis due to release of preformed thyroid hormone that lasts for 1 to 3 months, followed by a more prolonged hypothyroid phase lasting up to 6 months, and eventual return to a euthyroid state. However, the types and degree of thyroid dysfunction are variable in these disorders, and individual patients may present with mild or more severe cases of thyrotoxicosis alone, hypothyroidism alone, or both types of thyroid dysfunction.

Thyroid peroxidase antibody and screening for postpartum thyroid dysfunction

Postpartum thyroid dysfunction (PPTD) is a common disorder which causes considerable morbidity in affected women. The availability of effective treatment for hypothyroid PPTD, the occurrence of the disease in subsequent pregnancies and the need to identify subjects who develop long term hypothyroidism, has prompted discussion about screening for this disorder. There is currently no consensus about screening as investigations hitherto have been variable in their design, definitions and assay frequency and methodology. There is also a lack of consensus about a suitable screening tool although thyroid peroxidase antibody (TPOAb) is a leading contender. We present data about the use of TPOAb in early pregnancy and its value as a screening tool. Although its positive predictive value is moderate, its sensitivity and specificity when used in early pregnancy are comparable or better compared to other times during pregnancy and the postpartum period. Recent studies have also confirmed this strategy to be cost effective and to compare favourably with other screening strategies. We also explore the advantages of universal screening.

Low urinary iodine postpartum is associated with hypothyroid postpartum thyroid dysfunction and predicts long-term hypothyroidism

BACKGROUND

Postpartum thyroid dysfunction (PPTD) is characterized by an early hyperthyroid phase followed, with peak prevalence at 6 months, by a hypothyroid phase which carries a risk of long-term hypothyroidism. Iodine has a major effect on thyroid function. Western Australia has previously been shown to be iodine replete.

OBJECTIVE

To examine the iodine status of women with and without PPTD and the relationship of iodine status postpartum with long-term hypothyroidism.

DESIGN

Case-control with follow-up.

PATIENTS

A total of 149 women at 6 months postpartum (74 PPTD, 75 controls) with 98 (46 PPTD, 52 controls) followed up at 12 years.

MEASUREMENTS

Urinary iodine concentration (UIC) and thyroid function at 6 months postpartum; thyroid function at 12-year follow-up.

RESULTS

At 6 months postpartum, median UIC (quartiles) for observed TSH ranges were: for TSH < 0·4 mU/l 130·0 μg/l (82·0, 170·0); for TSH 0·4-4·0 mU/l 123·0 μg/l (80·5, 168·0); for TSH > 4·0 mU/l 85·0 μg/l (40·0, 141·5), P = 0·018. The odds ratio (OR) of hypothyroid PPTD with each unit of decreasing log iodine was 2·54, (95%CI: 1·47, 4·35), and with UIC < 50 μg/l, OR 4·22, (95%CI: 1·54, 11·55). In the long term, decreased log UIC significantly predicted hypothyroidism at 12-year follow-up (P = 0·002); as did UIC < 100 μg/l (P = 0·03) and UIC < 50 μg/l (P = 0·02). The association was independent of antibody status.

CONCLUSION

Low UIC measured at 6 months postpartum is associated with hypothyroid PPTD and independently predicts long-term hypothyroidism. We believe that it results from more severe preceding destructive thyroiditis, with discharge of thyroidal iodine, and thereby predicts a greater risk of long-term hypothyroidism.

[Autoimmune thyroiditis (Hashimoto's thyroiditis): current diagnostics and therapy]

Hashimoto's thyroiditis is a common autoimmune thyroid disease with preference of female gender. The chronic thyroiditis is characterized by autoantibodies against thyroid peroxidase and thyroglobulin. With manifestation, there is often a subclinical hypothyroidism that finally progresses to a persistent hypothyroidism with typical clinical symptoms and the need of hormonal substitution in succession of the lymphocytic infiltration of the thyroid. The ultrasound of the thyroid shows a hypoechogenic and inhomogeneous parenchyma. Autoimmune thyroiditis is frequently associated with autoimmune disease of other organs, such as vitiligo, Addison's disease, diabetes mellitus type 1, often in the sense of polyglandular syndrome 2.

Thyroid function and human reproductive health

Via its interaction in several pathways, normal thyroid function is important to maintain normal reproduction. In both genders, changes in SHBG and sex steroids are a consistent feature associated with hyper- and hypothyroidism and were already reported many years ago. Male reproduction is adversely affected by both thyrotoxicosis and hypothyroidism. Erectile abnormalities have been reported. Thyrotoxicosis induces abnormalities in sperm motility, whereas hypothyroidism is associated with abnormalities in sperm morphology; the latter normalize when euthyroidism is reached. In females, thyrotoxicosis and hypothyroidism can cause menstrual disturbances. Thyrotoxicosis is associated mainly with hypomenorrhea and polymenorrhea, whereas hypothyroidism is associated mainly with oligomenorrhea. Thyroid dysfunction has also been linked to reduced fertility. Controlled ovarian hyperstimulation leads to important increases in estradiol, which in turn may have an adverse effect on thyroid hormones and TSH. When autoimmune thyroid disease is present, the impact of controlled ovarian hyperstimulation may become more severe, depending on preexisting thyroid abnormalities. Autoimmune thyroid disease is present in 5-20% of unselected pregnant women. Isolated hypothyroxinemia has been described in approximately 2% of pregnancies, without serum TSH elevation and in the absence of thyroid autoantibodies. Overt hypothyroidism has been associated with increased rates of spontaneous abortion, premature delivery and/or low birth weight, fetal distress in labor, and perhaps gestation-induced hypertension and placental abruption. The links between such obstetrical complications and subclinical hypothyroidism are less evident. Thyrotoxicosis during pregnancy is due to Graves' disease and gestational transient thyrotoxicosis. All antithyroid drugs cross the placenta and may potentially affect fetal thyroid function.

Postpartum thyroid dysfunction and the long-term risk of hypothyroidism: results from a 12-year follow-up study of women with and without postpartum thyroid dysfunction

BACKGROUND

The long-term risk of hypothyroidism following postpartum thyroid dysfunction (PPTD) is uncertain. Most previous studies have been small, short-term or have lacked a control group.

OBJECTIVE

To ascertain the long-term risk of hypothyroidism in women following PPTD. Design and participants A 12-year longitudinal study of 409 women (including 71 with PPTD) who previously participated in a PPTD prevalence study.

MEASUREMENTS

The primary outcome measure was hypothyroidism (defined as TSH greater than 4 mU/l or on thyroxine replacement) at follow-up. Outcomes in women with and without PPTD were compared by logistic regression. Receiver operating characteristic analysis was used to determine the optimal cut-off for baseline TSH as a predictor of hypothyroidism in the cohort.

RESULTS

At follow-up, hypothyroidism was present in 27 of 71 women who had PPTD at baseline (38%) and 14 of 338 women without PPTD (4%). From multivariate analysis, odds ratios (with 95% confidence intervals) for hypothyroidism were - 4.8 (1.6, 14.1) for PPTD; 8.2 (2.8, 24.6) for positive thyroid peroxidase antibodies (TPOAb); 9.7 (2.6, 37.0) for the hypothyroid phase of PPTD and 51.4 (19.2, 137.5) for hypothyroid PPTD with positive TPOAb. A baseline TSH above 2.6 mU/l was the optimal cut-off for predicting hypothyroidism (sensitivity 76%, specificity 86%).

CONCLUSIONS

PPTD is a strong predictor of hypothyroidism in the long-term. Women who present with postpartum hypothyroidism or have positive TPOAb are at particularly high risk, suggesting that close long-term follow-up is advisable if thyroxine replacement is not instituted at an early stage.

Screening for thyroid disease: defining high-risk populations

The pros and cons of population screening for thyroid disease have been hotly debated over the past several decades. This article addresses the issue from the point of view of the potential benefit of screening, that is, disease detection. Earlier diagnoses of hypothyroidism, hyperthyroidism, thyroid nodules, thyroid cancer and so on, with implementation of the indicated diagnostic and therapeutic interventions, avoid the adverse consequences of unrecognized and untreated progressive disease. Arguments against screening and case-finding often focus on cost considerations. To achieve the greatest yield at the lowest cost, our emphasis is on vulnerable populations with associated risk factors, and special situations such as pregnancy.

Thyroid dysfunction and autoantibodies during pregnancy as predictive factors of pregnancy complications and maternal morbidity in later life

CONTEXT

Knowledge is scarce concerning the significance of thyroid dysfunction/antibodies during pregnancy in regard to pregnancy complications/later maternal morbidity.

OBJECTIVE

The aim of this study was to evaluate the association between maternal thyroid dysfunction/antibodies during pregnancy and pregnancy complications or later maternal hypertension, diabetes, and thyroid disease.

DESIGN AND SETTING

We studied a prospective population-based cohort, Northern Finland Birth Cohort 1986 (NFBC 1986), with follow-up of 20 yr. Medication and hospital discharge records were used to assess maternal morbidity to hypertension, diabetes, and thyroid diseases.

PARTICIPANTS

The study consisted of mothers of NFBC 1986 with early pregnancy serum samples for thyroid function and antibody analyses (n = 5805). Mothers were grouped and compared according to these test results.

MAIN OUTCOME MEASURES

We focused on preeclampsia and gestational diabetes during index pregnancy, later maternal hypertension, diabetes, and thyroid disease morbidity and total mortality.

RESULTS

Thyroid dysfunction and antibodies were not associated with pregnancy complications. Overt hypothyroidism was associated with subsequent maternal thyroid disease [hazard ratio (HR) (95% confidence interval), 17.7 (7.8-40.6)] and diabetes [6.0 (2.2-16.4)]. Subclinical hypothyroidism [3.3 (1.6-6.9)], TPO-Ab-positivity [4.2 (2.3-7.4)], and TG-Ab-positivity [3.3 (1.9-6.0)] were also associated with later thyroid disease. No association was found between thyroid dysfunction/antibodies and hypertension or overall mortality.

CONCLUSIONS

Thyroid dysfunction and antibodies during pregnancy seem to predict later thyroid disease. Overt hypothyroidism poses risk of diabetes.

Postpartum fatigue and evidence-based interventions

The aim of this article is to review postpartum fatigue, especially as it relates to the occurrence and pathophysiology of three common postpartum conditions known to contribute to fatigue: anemia, infection/inflammation, and thyroid dysfunction. Fatigue is an unrelenting condition that affects physical and mental health, and it has implications for everyday activities, motivation, and social interactions. Although individuals of all ages and both genders are at risk for developing fatigue, postpartum fatigue is particularly challenging, because the new mother has demanding life tasks to accomplish during this period of time. Postpartum fatigue may impact postpartum maternal role attainment and may place a woman at increased risk for postpartum depression. Although several treatable physiological conditions common during the postpartum period are known to increase fatigue, none of these conditions is a part of the usual assessment of healthy postpartum women. For many women, subtle fatigue may develop, linger or worsen, and even lead to depression, with both the woman and her care provider unaware.

Hyperthyroidism

Thyrotoxicosis is a condition resulting from elevated levels of thyroid hormone. In this article, the authors review the presentation, diagnosis, and management of various causes of thyrotoxicosis.

Dermatologic aspects of thyroid disease

Thyroid disorders commonly have dermatologic manifestations. The purpose of the present chapter is to review and emphasize potential clinical dermatologic findings that can occur with Graves' disease, hypothyroidism and thyroid cancer. In autoimmune diseases such as Graves' disease and Hashimoto's thyroiditis the skin manifestations may be related to either thyroid hormone levels themselves or to the associated T and/or B cell abnormalities. Thyroid cancer may be associated with various syndromes that could have significant skin manifestations.