Prevention and treatment of postpartum Graves' disease

Hyperthyroidism During Pregnancy: Etiology, Diagnosis and Management

Pregnancy has marked effects on thyroid physiology and autoimmune thyroid disease tends to ameliorate through gestation due to the general immunosuppression seen in pregnancy. There is a need for trimester-specific thyroid hormone reference ranges. Hyperthyroidism in pregnancy – usually due to Graves' disease – is not common but, if the patient is compliant, a good outcome can be expected for both mother and child if treatment with anti-thyroid drugs (propylthiouracil is preferred) is instituted. Thyroid-stimulating hormone receptor antibody should be measured at 36 weeks in such patients in order to predict the possibility of neonatal hyperthyroidism. Transient gestational hyperthyroidism is often associated with hyperemesis gravidarum and thyroid function should be checked in patients severely affected by this condition. Radioiodine therapy is contraindicated in pregnancy but thyroid surgery may be performed safely in the second trimester. Autoimmune thyroiditis and Graves’ hyperthyroidism occur quite commonly in postpartum women.

Hyperthyroidism during pregnancy: etiology, diagnosis and management

Pregnancy has marked effects on thyroid physiology and autoimmune thyroid disease tends to ameliorate through gestation due to the general immunosuppression seen in pregnancy. There is a need for trimester-specific thyroid hormone reference ranges. Hyperthyroidism in pregnancy - usually due to Graves' disease - is not common but, if the patient is compliant, a good outcome can be expected for both mother and child if treatment with anti-thyroid drugs (propylthiouracil is preferred) is instituted. Thyroid-stimulating hormone receptor antibody should be measured at 36 weeks in such patients in order to predict the possibility of neonatal hyperthyroidism. Transient gestational hyperthyroidism is often associated with hyperemesis gravidarum and thyroid function should be checked in patients severely affected by this condition. Radioiodine therapy is contraindicated in pregnancy but thyroid surgery may be performed safely in the second trimester. Autoimmune thyroiditis and Graves' hyperthyroidism occur quite commonly in postpartum women.

Miscarriage, and TNF-α and osteopontin relationship in women patients with Hashimoto's thyroiditis

OBJECTIVE

Infertility and reproductive impairment can be compromised by abnormalities in both endocrine and immune system. TNF-α promotes apoptotic cell death in fetal membrane tissues and pro-inflammatory, proapoptotic, and procoagulant properties of TNF-α probably contribute to widely accepted abortogenic profile of this cytokine. The aim of this study was to assess the alteration in the levels of TSH, FT3, FT4, TNF-α, osteopontin in pregnant and controls.

METHODS

Study subjects were 28 pregnant women, 28 non-pregnant women, and 28 healthy controls. All subjects underwent venous blood drawing for levels of TNF-α, osteopontin, and also hormonal assays including the levels of anti-TPO, anti-TG antibodies, TSH, FT3, FT4.

RESULTS

Both patient and control groups are similar in terms of age. Pregnancy age in conceived patients is 23.64 ± 2.040. No statistically meaningful relation was found in correlation analysis between TNF-α and osteopontin among the groups (p = 0.963). Anti-thyroglobuline antibody and anti-microsomal antibody levels were found to be higher in patients with non-pregnant patients with Hashimoto thyroiditis than the control group (p < 0.001). No statistically meaningful relation was found in terms of TNF-α (p = 0.66) and osteopontin serum levels (p = 0.50) in patient groups with or without miscarriage history.

CONCLUSIONS

In our study, no statistically meaningful relation was found in terms of TNF-α and osteopontin serum levels in patient groups with and without miscarriage history.

Increased fetal abortion rate in autoimmune thyroid disease is related to circulating TPO autoantibodies in an autoimmune thyroiditis animal model

OBJECTIVE

To determine the fertility and abortion rates in a mouse model of autoimmune thyroiditis and its relationship with circulating anti-thyroid peroxidase (TPO) antibody.

DESIGN

Experimental animal study.

SETTING

University research laboratory.

ANIMAL(S)

C57bl/6 mice.

INTERVENTION(S)

Female C57bl/6 mice immunized with recombinant mouse TPO (rmTPO) in complete Freund adjuvant (CFA) or glutathione-S-transferase (GST-CFA) were allowed to mate. The pregnant mice were killed on day 14 of pregnancy for assessment of fetal development. The effects of TPO antibody on preimplantation embryo development and implantation rate were also studied.

MAIN OUTCOME MEASURE(S)

Litter size, resorption rate, preimplantation embryo development, and implantation rate.

RESULT(S)

All of the mice immunized with rmTPO-CFA possessed anti-TPO antibody. They had reduced litter size and increased incidence of resorbed fetus compared with the control. Higher serum TSH levels, but not T(4) levels, were demonstrated after rmTPO-CFA immunization. Anti-TPO antibody bound to preimplantation embryos. Treatment of the embryos with the antibody marginally decreased the formation of 3/4-cell embryos but had no effect on the subsequent development and implantation compared with the nonimmune control sera.

CONCLUSION(S)

Autoimmune thyroiditis is associated with reduced fertility and higher incidence of fetal loss. The anti-TPO antibody may affect post-implantation embryo development, leading to fetal loss.

Treatment of post-partum thyrotoxicosis

Thyrotoxicosis occurs more frequently during the post-partum period than at other times in women of childbearing age. Graves' disease and post-partum thyroiditis are two major causes of thyrotoxicosis in this period. The major task lies in differentiation of these two diseases in the post-partum period; since throtoxicosis caused by post-partum thyroiditis usually does not require treatment. The radioiodine uptake is elevated or normal in Graves' disease and low in post-partum thyroiditis, and TSH-receptor antibodies are positive in Graves' and negative in post-partum thyroiditis. Post-partum thyrotoxicosis due to Graves' disease may be treated with radioiodine but it requires radiation safety measurements for infant and is contraindicated if the mother is breast-feeding. Antithyroid drugs are the mainstay of the treatment of post-partum thyrotoxicosis. Recent investigations conclude that neither propylthiouracil nor methimazole cause any alterations in thyroid function and physical and mental development of infants breast-fed by lactating thyrotoxic mothers, and both can be safely administered in moderately high doses during lactation.

The safety and efficacy of antithyroid drugs

Thionamides, selective inhibitors of thyroid peroxidase-mediated iodination by tyrosine residues in thyroglobulin, have been effectively used in the treatment of hyperthyroidism. The choices for initial treatment of patients with Graves' disease differ in various countries, and many physicians around the world prefer to administer thionamide drugs as the first choice of treatment for patients with hyperthyroidism. Although some thyroidologists more often consider radioiodine to be the treatment of choice because of its safety and ease of administration, thionamides remain the mainstay of treatment in thyrotoxic children and adolescents and in hyperthyroid women during pregnancy, postpartum period and lactation. A recent study with continuous thionamide treatment for patients with Graves' disease shows its efficacy, safety and cost-benefit properties. Further studies of the effectiveness of continuous thionamide therapy in patients with thyrotoxicosis need to be designed and implemented to determine indications for such therapy in children, adolescents and adults with diffuse toxic goiter, in particular, in those who have had recurrence of hyperthyroidism after discontinuation of one complete course of treatment.

Thyroid disorders associated with pregnancy: etiology, diagnosis, and management

Pregnancy has an effect on thyroid economy with significant changes in iodine metabolism, serum thyroid binding proteins, and the development of maternal goiter especially in iodine-deficient areas. Pregnancy is also accompanied by immunologic changes, mainly characterized by a shift from a T helper-1 (Th1) lymphocyte to a Th2 lymphocyte state. Thyroid peroxidase antibodies are present in 10% of women at 14 weeks' gestation, and are associated with (i) an increased pregnancy failure (i.e. abortion), (ii) an increased incidence of gestational thyroid dysfunction, and (iii) a predisposition to postpartum thyroiditis. Thyroid function should be measured in women with severe hyperemesis gravidarum but not in every patient with nausea and vomiting during pregnancy. Graves hyperthyroidism during pregnancy is best managed with propylthiouracil administered throughout gestation. Thyroid-stimulating hormone-receptor antibody measurements at 36 weeks' gestation are predictive of transient neonatal hyperthyroidism, and should be checked even in previously treated patients receiving thyroxine. Postpartum exacerbation of hyperthyroidism is common, and should be evaluated in women with Graves disease not on treatment. Radioiodine therapy in pregnancy is absolutely contraindicated. Hypothyroidism (including subclinical hypothyroidism) occurs in about 2.5% of pregnancies, and may lead to obstetric and neonatal complications as well as being a cause of infertility. During the last few decades, evidence has been presented to underpin the critical importance of adequate fetal thyroid hormone levels in order to ensure normal central and peripheral nervous system maturation. In iodine-deficient and iodine-sufficient areas, low maternal circulating thyroxine levels have been associated with a significant decrement in child IQ and development. These data suggest the advisability of further evaluation for a screening program early in pregnancy to identify women with hypothyroxinemia, and the initiation of prompt treatment for its correction. Hypothyroidism in pregnancy is treated with a larger dose of thyroxine than in the nonpregnant state. Postpartum thyroid dysfunction (PPTD) occurs in 50% of women found to have thyroid peroxidase antibodies in early pregnancy. The hypothyroid phase of PPTD is symptomatic and requires thyroxine therapy. A high incidence (25-30%) of permanent hypothyroidism has been noted in these women. Women having transient PPTD with hypothyroidism should be monitored frequently, as there is a 50% chance of these patients developing hypothyroidism during the next 7 years.

Epidemiology and prevention of thyroid disease in pregnancy

Pregnancy has variable effects on thyroid hormone concentrations throughout pregnancy as well as being associated with goiter. The latter is largely preventable by ensuring optimal iodine intake of at least 200 microg/d. Immunologic changes in pregnancy include a so-called T(H)2 shift that reverts to T(H)1 status around birth or early in the postpartum period. Hyperthyroidism during gestation, usually caused by Graves' disease, is rare (0.2%) and is best managed medically with propylthiouracil; thyroid-stimulating antibodies should be measured. Prevention of the deleterious effects of Graves' disease includes adequate preconception advice, adequate monitoring during pregnancy, and total avoidance of (131)I therapy during pregnancy. Hypothyroidism during pregnancy has an incidence of 2.5% although there is a 10% incidence of thyroid peroxidase (TPO)-antibody positivity in early gestation. There are convincing epidemiologic data to show that suboptimal thyroid function in pregnancy is associated with impaired neurointellectual development (e.g., 19% with IQ < 85 compared to 5% in one study). Therefore, there is a case for screening for thyroid function in early pregnancy with thyroxine (T(4)) intervention therapy. Maintenance of optimal iodine intake is critical to prevent nonautoimmune gestational maternal hypothyroxinaemia. Postpartum thyroid dysfunction (PPTD) occurs in 5%-9% of women and in up to 50% of TPO-antibody positive women (as ascertained in early pregnancy). Prevention of PPTD at this time could only be achieved by pregestational ablation of the thyroid. Another approach is to at least improve the prediction of postpartum thyroid disease (PPT) because the TPO antibody has a sensitivity of only 50%.

Postpartum proptosis with ophthalmopathy

BACKGROUND

Postpartum thyroid disease presents in two forms: postpartum thyroiditis (PPT) and postpartum Graves' disease (PPGD).

CASE REPORT

A case of postpartum thyroid dysfunction with ophthalmopathy is presented.

DISCUSSION

In women diagnosed with Graves' disease during the ages of 20 to 35 years, 66% have a postpartum onset; women with a previous history of Graves' disease frequently relapse in the postpartum period. Additionally, up to 25 to 30% of postpartum women can develop permanent hypothyroidism from postpartum thyroiditis. The signs and symptoms of PPT and PPGD may be indefinite after delivery and often go undiagnosed. Because complications can be significant and may become irreversible, proper diagnosis and timely treatment is important.

Thyroid disease in relation to pregnancy: a decade of change

Inspection of the references cited in this review indicates that much work has occurred in the area of thyroid and pregnancy during the last decade. Significant advances in our understanding of the immunology of pregnancy and the effect of thyroid disease on this process have taken place. The role of hCG in the physiology of pregnancy and its relevance to thyroid function has been an emerging theme. There is still no clear explanation for the association between thyroid antibodies and infertility or miscarriage. During the last decade a general concensus has developed in relation to the management of hyperthyroidism in pregnancy although there are still variations in antithyroid drug use at this time. The aetiological classification of congenital hyper- and hypothyroidism utilizing new technologies has opened up a new perspective on these disorders. Attention has been drawn to the importance of treating maternal hypothyroidism with adequate thyroid replacement therapy and to the possibility of impaired child neuropsychological development consequent on low maternal thyroid hormone concentration in early gestation in non iodine deficient areas. Significant advances have been made during the last decade in the description of the clinical features and in our understanding of the pathogenesis of postpartum thyroid disease. The importance of long-term follow up of selected patient groups has also been emphasized.

Thyroid Function during Pregnancy

Background: This Case Conference reviews the normal changes in thyroid activity that occur during pregnancy and the proper use of laboratory tests for the diagnosis of thyroid dysfunction in the pregnant patient.

Case: A woman in the 18th week of pregnancy presented with tachycardia, increased blood pressure, severe vomiting, increased total and free thyroid hormone concentrations, a thyroid-stimulating hormone (TSH) concentration within the reference interval, and an increased human chorionic gonadotropin (hCG) β-subunit concentration.

Issues: During pregnancy, normal thyroid activity undergoes significant changes, including a two- to threefold increase in thyroxine-binding globulin concentrations, a 30–100% increase in total triiodothyronine and thyroxine concentrations, increased serum thyroglobulin, and increased renal iodide clearance. Furthermore, hCG has mild thyroid stimulating activity. Pregnancy produces an overall increase in thyroid activity, which allows the healthy individual to remain in a net euthyroid state. However, both hyper- and hypothyroidism can occur in pregnant patients. In addition, two pregnancy-specific conditions, hyperemesis gravidarum and gestational trophoblastic disease, can lead to clinical hyperthyroidism. The normal changes in thyroid activity and the association of pregnancy with conditions that can cause hyperthyroidism necessitates careful interpretation of thyroid function tests during pregnancy.

Conclusion: Assessment of thyroid function during pregnancy should be done with a careful clinical evaluation of the patient’s symptoms as well as measurement of TSH and free, not total, thyroid hormones. Measurement of thyroid autoantibodies may also be useful in selected cases to detect maternal Graves disease or Hashimoto thyroiditis and to assess risk of fetal or neonatal consequences of maternal thyroid dysfunction.

Hyperthyroidism in pregnancy: diagnosis and treatment

Hyperthyroidism due to autoimmune Graves' disease is the leading cause of thyrotoxicosis in pregnant women. The peak incidence of the disease is in the second through the fourth decade of life, which encompasses the reproductive years for women. Although menstrual irregularity is frequent in women with mild to moderate hyperthyroidism, convincing evidence that fertility is impaired is lacking. In general, 2 of every 1000 pregnancies have been reported to be complicated by hyperthyroidism. Hyperthyroidism associated with pregnancy may pose a challenging diagnostic and therapeutic dilemma. The current review focuses on the discussion of symptomatology and diagnosis of the disease, on therapeutic options available to women presenting with hyperthyroidism during gestation, and on the controversy surrounding maternal and fetal outcome in pregnancies complicated by thyrotoxicosis.