Serum human chorionic gonadotropin concentrations greater than 400,000 IU/L are invariably associated with suppressed serum thyrotropin concentrations

An evaluation of serum blood parameters and amyloid-A levels in women with hyperemesis gravidarum; A prospective observational study

This study aimed to investigate whether serum amyloid A (AA) level can be used as a biomarker in women with hyperemesis gravidarum (HEG). This prospective observational study was conducted at the Antalya Training and Research Hospital Gynecology and Obstetrics Clinic, Türkiye, between July and December 2023. Forty women diagnosed with HEG and 40 healthy women were included. No statistically significant differences were observed between the groups in terms of sociodemographic data such as age, body mass index, family history, educational status, economic level, place of residence, occupation, smoking and alcohol use, or drug habits. However, obstetric characteristics such as number of miscarriages, number of dilatation curettages, and gestational age and laboratory values including complete blood count, hematocrit, leukocyte, neutrophil, lymphocyte, platelet, free T4, albumin, alanine aminotransferase, aspartate aminotransferase, urea, creatinine, hs-C-reactive protein, and sodium (P > .05) all differed significantly. In addition, significant differences were observed between the HEG and healthy groups in terms of numbers of gravidities (2 [1-3] vs 1 [0-1], respectively, P < .001), numbers of parities (1 [0-1] vs 1 [0-1], P < .001), numbers of living children (1 [0-2] vs 1 [0-1], P < .001), presenting complaints (nausea 0 [0%], nausea + vomiting 0 [0%], none 40 [100.0%] vs nausea 27 [67.5%], nausea + vomiting 13 [32.5%], none 0 [0%], P < .001), serum thyroid-stimulating hormone (1.16 ± 0.56 vs 1.81 ± 0.624, P = .004), potassium (4.1 ± 0.7 vs 3.8 ± 0.2, P = .001), and AA values (7.29 ± 2.61 vs 10.74 ± 3.04, P < .001). At receiver operating characteristic analysis, the area under the curve (AUC: 0.881) was statistically significant for serum AA (P: <.001), with a cutoff value of ≥ 8.79 ([95% confidence interval] 0.743-0.919, sensitivity 87.4%, specificity 80.2%). The positive predictive value of serum AA was 81.1% and the negative predictive value was 80.4%. The study results showed that serum AA can be used as a diagnostic biomarker in HEG. Prospective studies involving more participants are now required to confirm our results.

Advances in the differential diagnosis of transient hyperthyroidism in pregnancy and Graves' disease

BACKGROUND

The occurrence of thyrotoxicosis during pregnancy is mainly attributed to gestational transient thyrotoxicosis (GTT) and Graves' disease (GD). It is important to distinguish between GTT and Graves' disease because the two diseases are treated very differently. However, a gold standard for the differential diagnosis of the two diseases is currently lacking, and the most common method of differentiation is based on past medical history and clinical presentation combined with thyroid-related antibodies.

METHODS

A literature search of the electronic databases PubMed, Embase, Medline, Google Scholar, Cochrane Library, China Knowledge Infrastructure, Wanfang Database, Chinese Scientific Journals Full Text Database and China Biomedical CD-ROM was performed. The search period ranged from journal inception until 2022. We used the following search terms in "All fields": {["thyroid" (common field) OR "thyroid" (subject line)] OR "hyperthyroidism" (common field)} AND {["pregnancy" (title) OR "pregnancy" (title)] AND "one over" (common field)} OR {["pregnancy" (common field) OR "pregnancy" (common field) OR "pregnancy" (subject line)] AND "Graves'" (common field)}.

RESULTS

In recent years, some clinical studies at home and abroad have proposed other meaningful differential indicators, such as thyroid stimulating hormone, chorionic gonadotropin, thyroid hormone levels and thyroid ultrasound.

CONCLUSION

The differential diagnostic significance of each of these indicators is summarised here with the goal of providing a better reference for the differential diagnosis of hyperthyroidism during pregnancy in clinical practice.

Hyperthyroidism: aetiology, pathogenesis, diagnosis, management, complications, and prognosis

Hyperthyroidism is a common condition with a global prevalence of 0·2-1·3%. When clinical suspicion of hyperthyroidism arises, it should be confirmed by biochemical tests (eg, low TSH, high free thyroxine [FT4], or high free tri-iodothyonine [FT3]). If hyperthyroidism is confirmed by biochemical tests, a nosological diagnosis should be done to find out which disease is causing the hyperthyroidism. Helpful tools are TSH-receptor antibodies, thyroid peroxidase antibodies, thyroid ultrasonography, and scintigraphy. Hyperthyroidism is mostly caused by Graves' hyperthyroidism (70%) or toxic nodular goitre (16%). Hyperthyroidism can also be caused by subacute granulomatous thyroiditis (3%) and drugs (9%) such as amiodarone, tyrosine kinase inhibitors, and immune checkpoint inhibitors. Disease-specific recommendations are given. Currently, Graves' hyperthyroidism is preferably treated with antithyroid drugs. However, recurrence of hyperthyroidism after a 12-18 month course of antithyroid drugs occurs in approximately 50% of patients. Being younger than 40 years, having FT4 concentrations that are 40 pmol/L or higher, having TSH-binding inhibitory immunoglobulins that are higher than 6 U/L, and having a goitre size that is equivalent to or larger than WHO grade 2 before the start of treatment with antithyroid drugs increase risk of recurrence. Long-term treatment with antithyroid drugs (ie, 5-10 years of treatment) is feasible and associated with fewer recurrences (15%) than short-term treatment (ie, 12-18 months of treatment). Toxic nodular goitre is mostly treated with radioiodine (131I) or thyroidectomy and is rarely treated with radiofrequency ablation. Destructive thyrotoxicosis is usually mild and transient, requiring steroids only in severe cases. Specific attention is given to patients with hyperthyroidism who are pregnant, have COVID-19, or have other complications (eg, atrial fibrillation, thyrotoxic periodic paralysis, and thyroid storm). Hyperthyroidism is associated with increased mortality. Prognosis might be improved by rapid and sustained control of hyperthyroidism. Innovative new treatments are expected for Graves' disease, by targeting B cells or TSH receptors.

SFE-AFCE-SFMN 2022 Consensus on the management of thyroid nodules : Thyroid nodules and pregnancy

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons, but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). The present section deals with the epidemiology and specificities of diagnosis and treatment of thyroid nodules in pregnant women.

Maternal thyroid function in multiple pregnancies - a systematic review

BACKGROUND

The function of the thyroid gland during pregnancy undergoes physiological changes to ensure the proper amount of thyroid hormones for both the pregnant woman and the fetus. Multiple pregnancies (MP) are characterized by specific differences compared to single pregnancies, e.g., higher concentrations of human chorionic gonadotropin, which also affect thyroid function. The aim was to collect available knowledge on maternal thyroid function in MP.

METHODS

We have systematically searched three databases: the PubMed/MEDLINE, Scopus and the Cochrane Library. The last search was run on the 4th of August 2022. We included full-text original observational and experimental studies written in English. Case reports, editorials, letters, conference abstracts, reviews and meta-analyses were excluded. No time criterion was established. Studies were considered eligible if at least one maternal thyroid function test was performed and reported. Studies on MP with a co-existing mole were excluded. The risk of bias was assessed with the use of the AXIS tool. The qualitative synthesis of evidence was applied.

RESULTS

The search strategy resulted in the identification of 821 manuscripts. After removing duplicates, we screened the titles and abstracts of 552 articles, out of which 57 were selected for full-text analysis. Finally, 12 articles were included in the review. They were conducted in 6 different countries and published between the years 1997 and 2022. The number of examined women with MP ranged from 9 to 1 626.

DISCUSSION AND CONCLUSIONS

Thyroid function differs between women with MP and SP. Scarce data are available on the topic, but MPs are most likely characterized by higher HCG levels, which influences thyroid-stimulating hormone and free thyroid hormone levels. These differences are mainly expressed in the 1st trimester of pregnancy. Separate population-based reference ranges are needed to correctly diagnose thyroid diseases in MP and to avoid unnecessary treatment. Further research is needed to fill the knowledge gaps.

Associations of exposure to cadmium, antimony, lead and their mixture with gestational thyroid homeostasis

Maintaining thyroid homeostasis during pregnancy is vital for fetal development. The few studies that have investigated associations between metal exposure and gestational thyroid function have yielded mixed findings. To evaluate the association of exposure to a mixture of toxic metals with thyroid parameters in 824 pregnant women from the Rhea birth cohort in Crete, Greece. Concentrations of three toxic metals [cadmium (Cd), antimony (Sb), lead (Pb)] and iodine were measured in urine using inductively coupled plasma mass spectrometry and thyroid hormones [Thyroid Stimulating Hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3)] were measured in serum in early pregnancy. Associations of individual metals with thyroid parameters were assessed using adjusted regression models, while associations of the metal mixture with thyroid parameters were assessed using Bayesian Kernel Machine Regression (BKMR).Women with high (3rd tertile) concentrations of urinary Cd, Sb and Pb, respectively, had 13.3 % (95%CI: 2.0 %, 23.2 %), 12.5 % (95%CI: 1.8 %, 22.0 %) and 16.0 % (95%CI: 5.7 %, 25.2 %) lower TSH compared to women with low concentrations (2nd and 1st tertile). In addition, women with high urinary Cd had 2.2 % (95%CI: 0.0 %, 4.4 %) higher fT4 and 4.0 % (95%CI: -0.1 %, 8.1 %) higher fT3 levels, and women with high urinary Pb had 4 % (95%CI: 0.2 %, 8.0 %) higher fT3 levels compared to women with low exposure. The negative association of Cd with TSH persisted only when iodine sufficiency was unfavorable. BKMR attested that simultaneous exposure to toxic metals was associated with decreased TSH and increased fT3 and revealed a potential synergistic interaction of Cd and Pb in association with TSH. The present results suggest that exposure to toxic metals even at low levels can alter gestational thyroid homeostasis.

Thyrotoxicosis: a rare presentation of molar pregnancy

A 49-year-old woman, G8P7, presented with 1 week of worsening vaginal bleeding and abdominal cramps in the setting of a recently discovered unplanned pregnancy. Vaginal ultrasound findings and a significantly elevated human chorionic gonadotropin (hCG) level were concerning for molar pregnancy. She developed signs of hyperthyroidism on the night of admission, for which the endocrinology team was consulted. Laboratory data were consistent with hyperthyroidism. The patient was believed to have thyrotoxicosis secondary to molar pregnancy with concern for impending thyroid storm. Her mental health disorder and bacteraemia made taking care of her further challenging. She was started on a beta-blocker, antithyroid agent and intravenous corticosteroids. She underwent an uncomplicated suction dilation and curettage (D&C), with resolution of her symptoms a few days after. At a follow-up appointment, the patient continued to be asymptomatic and was feeling well.

Establishment of assay method- and trimester-specific reference intervals for thyroid hormones during pregnancy in Chengdu, China

Background

The reference intervals of thyroid hormone will change at different stages of pregnancy because of physiological alterations. On the other hand, the reference intervals of thyroid hormone will also change in different detection systems due to the manufacturer's methodology as well as a different race. The objective of this study was to establish the assay method‐ and trimester‐specific reference intervals for thyroid‐stimulating hormone, free thyroxine and free triiodothyronine for pregnant women in Chengdu.

Methods

A prospective, population‐based cohort study involved 23,701 reference samples of pregnant women during the three trimesters and 8646 non‐pregnant women with pre‐pregnancy clinical and laboratory tests. The 2.5th and 97.5th percentiles were calculated as the reference intervals for thyroid‐stimulating hormone, free thyroxine and free triiodothyronine at each trimester of pregnant women according to ATA Guidelines.

Results

The reference interval of thyroid‐stimulating hormone in the 2.5th and 97.5th percentiles has a significant increasing trend from the first trimester, to second trimester and to third trimester, which was 0.08–3.79 mIU/L for the first trimester, and 0.12–3.95 mIU/L for the second trimester and 0.38–4.18 mIU/L for the third trimester, respectively (p < 0.001). However, the reference intervals of free thyroxine and free triiodothyronine in the 2.5th and 97.5th percentiles have significant decreasing trends from the first trimester, to second trimester and to third trimester, which were 11.87–18.83 pmol/L and 3.77–5.50 pmol/L for the first trimester, and 11.22–18.19 pmol/L and 3.60–5.41 pmol/L for the second trimester, and 10.19–17.42 pmol/L and 3.37–4.79 pmol/L for the third trimester, respectively (both p < 0.001).

Conclusion

It is necessary to establish assay method‐ and trimester‐specific reference intervals for thyroid‐stimulating hormone, free thyroxine, and free triiodothyronine because the reference intervals of these thyroid hormones are significantly different at different stages of pregnancy.

Clinical presentation and diagnosis of Gestational Trophoblastic Disease

Gestational trophoblastic disease (GTD) is a heterogeneous group of pregnancy-related disorders characterized by abnormal proliferation of trophoblastic tissue. It encompasses the premalignant partial and complete hydatidiform mole but also the malignant invasive mole, choriocarcinoma, placental-site trophoblastic tumor, and epithelioid trophoblastic tumor. The clinical presentation changed to earlier detection after the introduction of first trimester ultrasounds. Patients are often asymptomatic, but vaginal bleeding continues to be the most common presenting symptom. Other symptoms can develop in the case of metastatic disease. Ultrasound, serum human chorionic gonadotrophin, and sometimes additional imaging such as CT, MRI, or PET can confirm the diagnosis and stage of disease. Familiarity with the pathogenesis, classification, imaging features, and treatment of GTD facilitates diagnosis and appropriate management.

Hyperthyroidism in molar pregnancy: β-HCG levels do not always reflect severity

BACKGROUND

Molar pregnancy is a complication characterised by abnormal benign or malignant proliferation of trophoblastic cells resulting in markedly elevated β-hCG (human chorionic gonadotrophin) levels, an established marker for the presence of the disease. Owing to the structural homology between β-hCG and TSH, the raised β-hCG can result in secondary hyperthyroidism.

METHODS

Two patients aged 20 (Case 1) and 31 years (Case 2) presented to the emergency department within a few days of each other complaining of vaginal bleeding associated with abdominal pain. Ultrasound evaluation, β-hCG and thyroid function tests were performed on both patients.

RESULTS

Both had elevated β-hCG levels and ultrasound evidence of molar pregnancy and were diagnosed with gestational trophoblastic disease (GTD) associated with hyperthyroidism based on thyroid function test results. Case 1 had lower β-hCG levels and free T4 levels compared with Case 2 but clinical assessment of the former revealed severe illness and more complicated course with the development of a thyroid storm. Case 2 had β-hCG levels almost double those of Case 1, yet was stable and her levels decreased much faster, reaching and maintaining undetectable levels.

CONCLUSIONS

These cases demonstrate that the β-hCG levels do not always correlate with disease severity and prognosis in patients with GTD.

Pitfalls in the assessment of gestational transient thyrotoxicosis

Gestational transient thyrotoxicosis (GTT) is associated with direct stimulation of the maternal thyroid gland by human chorionic gonadotropin (hCG). It is characterized by slightly higher thyroid hormone and lower thyroid-stimulating hormone (TSH) levels in early pregnancy and mild or no symptoms. While GTT must be distinguished from Graves' disease (GD), which is associated with maternal and fetal complications, treated GD and new-onset GD in pregnancy are occasionally challenging to distinguish. Evaluating serum hCG levels and TSH receptor antibody (TRAb) titers can help, but the results are not irrefutable due to pregnancy-related immunosuppression. Moreover, GTT can follow unusual clinical courses in relation to some pregnancy complications. Excessive hCG production can cause severe GTT symptoms in patients with hyperemesis gravidarum, trophoblastic disease, or multiple pregnancies. Thyrotoxicosis can emerge beyond the second trimester in patients with gestational diabetes mellitus and mirror syndrome, because of delayed elevations in the hCG levels. Detailed knowledge about GTT is necessary for correct diagnoses and its appropriate management. This review focuses on the diagnosis of GTT, and, particularly, its differentiation from GD, and unusual clinical conditions associated with GTT that require comprehensive management.

Fertility and Pregnancy in Women With Hypopituitarism: A Systematic Literature Review

CONTEXT

Human reproduction is mainly governed from the hypothalamic-adrenal-gonadal (HPG) axis, which controls both ovarian morphology and function. Disturbances in the secretion of other anterior pituitary hormones (and their respective endocrine axes) interfere with HPG activity and have been linked to fertility problems. In normal pregnancy, maintenance of homeostasis is associated with continuous changes in pituitary morphology and function, which need to be considered during hormone replacement in patients with hypopituitarism.

DESIGN

We conducted a systematic PubMed literature review from 1969 to 2019, with the following keywords: fertility and hypopituitarism, pregnancy and hypopituitarism, and ovulation induction and hypopituitarism. Case reports or single-case series of up to 2 patients/4 pregnancies were excluded.

RESULTS

Eleven publications described data on fertility (n = 6) and/or pregnancy (n = 7) in women with hypopituitarism. Women with hypopituitarism often need assisted reproductive treatment, with pregnancy rates ranging from 47% to 100%. In patients achieving pregnancy, live birth rate ranged from 61% to 100%. While glucocorticoids, levothyroxine, and desmopressin are safely prescribed during pregnancy, growth hormone treatment regimens vary significantly between countries, and several publications support a positive effect in women seeking fertility.

CONCLUSIONS

In this first systematic review on fertility, ovulation induction, and pregnancy in patients with hypopituitarism, we show that while literature is scarce, birth rates are high in patients achieving pregnancy. However, prospective studies are needed for evaluating outcomes in relationship to treatment patterns. Replacement therapy in hypopituitarism should always mimic normal physiology, and this becomes challenging with changing demands during pregnancy evolution.

Late Effects of Parasellar Lesion Treatment: Hypogonadism and Infertility

Central hypogonadism, also defined as hypogonadotropic hypogonadism, is a recognized complication of hypothalamic-pituitary-gonadal axis damage following treatment of sellar and parasellar masses. In addition to radiotherapy and surgery, CTLA4-blocking antibodies and alkylating agents such as temozolomide can also lead to hypogonadism, through different mechanisms. Central hypogonadism in boys and girls may lead to pubertal delay or arrest, impairing full development of the genitalia and secondary sexual characteristics. Alternatively, cranial irradiation or ectopic hormone production may instead cause early puberty, affecting hypothalamic control of the gonadostat. Given the reproductive risks, discussion of fertility preservation options and referral to reproductive specialists before treatment is essential. Steroid hormone replacement can interfere with other replacement therapies and may require specific dose adjustments. Adequate gonadotropin stimulation therapy may enable patients to restore gametogenesis and conceive spontaneously. When assisted reproductive technology is needed, protocols must be tailored to account for possible long-term gonadotropin insufficiency prior to stimulation. The aim of this review was to provide an overview of the risk factors for hypogonadism and infertility in patients treated for parasellar lesions and to give a summary of the current recommendations for management and follow-up of these dysfunctions in such patients. We have also briefly summarized evidence on the physiological role of pituitary hormones during pregnancy, focusing on the management of pituitary deficiencies.

Thyroid function among women with gestational trophoblastic diseases. A cross-sectional study

BACKGROUND

Gestational trophoblastic diseases (GTDs) are treatable rare tumors with wide distribution. The estimated incidence of GTDs varies dramatically between different regions globally. In early pregnancy, there may be high human chorionic gonadotropin (HCG) concentrations, normal or slightly increased free T4 (fT4) and subnormal thyroid-stimulating hormone (TSH), causing hyperthyroidism ranging from subclinical to severe. Beta-HCG causes thyrotoxicosis through thyroid stimulation in patients with trophoblastic tumors.

OBJECTIVE

To assess thyroid function among patients diagnosed with complete or partial hydatidiform mole, within the GTD spectrum.

DESIGN AND SETTING

Cross-sectional study based on patients' medical records at Van University Hospital, Van, Turkey.

METHODS

50 patients monitored due to diagnoses of hydatidiform mole were included and were examined regarding thyroid function. Thyroid gland size and volume were measured using thyroid ultrasonography. Beta-HCG, TSH, fT4, free T3 (fT3), total T4 (TT4), total T3 (TT3), anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin (anti-TG) and thyroglobulin levels were measured.

RESULTS

Among these patients, 15 (30%) were diagnosed with complete hydatidiform mole and 35 (70%) with partial hydatidiform mole, according to pathology results. Those with complete hydatidiform mole were older (P = 0.003), with higher number of pregnancies (P = 0.032), lower TSH level (P = 0.011) and higher fT4 and TT4 levels (P = 0.04; P = 0.028), compared with partial hydatidiform mole patients.

CONCLUSION

In hydatidiform mole patients, thyroid disease severity increases with age, parity, beta-HCG level and mole size. However, prospective multicenter studies on this topic are needed, with larger numbers of patients and closer monitoring.

Hyperthyroidism in the pregnant woman: Maternal and fetal aspects

Hyperthyroidism during pregnancy is uncommon. Nonetheless, prompt identification and adequate management of hyperthyroidism in a pregnant woman is essential, because uncontrolled thyrotoxicosis significantly increases the risk of maternal and fetal complications. Also, fetal prognosis may be affected by the transplacental passage of maternal thyroid stimulating antibodies or thyrostatic agents, both of which may disrupt fetal thyroid function. Birth defects have been reported in association with the use of antithyroid drugs during early pregnancy. Although rarely, offspring of mothers with Graves’ disease may develop fetal/neonatal hyperthyroidism, the management of which requires a close collaboration between endocrinologists, obstetricians, and neonatologists.

Because of the above considerations, the management of pregnant and lactating women with hyperthyroidism requires special care, bearing in mind that both maternal thyroid excess per se and related treatments may adversely affect the newborn’s health.

In this review we discuss the diagnosis and management of hyperthyroidism in pregnancy, along with the impact of thyrotoxicosis and medications on fetal outcome.

Variables Contributing to Thyroid (Dys)Function in Pregnant Women: More than Thyroid Antibodies?

Variability in thyroid function in pregnant women is the result of 2 main determinants, each accounting for approximately half of it. The first is the genetically determined part of which the knowledge increases fast, but most remains to be discovered. The second determinant is caused by an ensemble of variables of which thyroid autoimmunity is the best known, but also by others such as parity, smoking, age, and BMI. More recently, new candidate variables have been proposed, such as iron, endocrine disruptors, and the ethnicity of the pregnant women. In the future, the diagnosis and treatment of thyroid (dys)function may be optimized by the use of each individual's pituitary-thyroid set point, corrected with a factor taking into account the impact of nongenetically determined variables.

2017 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and the Postpartum

BACKGROUND

Thyroid disease in pregnancy is a common clinical problem. Since the guidelines for the management of these disorders by the American Thyroid Association (ATA) were first published in 2011, significant clinical and scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid disease in women during pregnancy, preconception, and the postpartum period.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations. The guideline task force had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid disease in pregnancy include recommendations regarding the interpretation of thyroid function tests in pregnancy, iodine nutrition, thyroid autoantibodies and pregnancy complications, thyroid considerations in infertile women, hypothyroidism in pregnancy, thyrotoxicosis in pregnancy, thyroid nodules and cancer in pregnant women, fetal and neonatal considerations, thyroid disease and lactation, screening for thyroid dysfunction in pregnancy, and directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid disease in pregnant and postpartum women. While all care must be individualized, such recommendations provide, in our opinion, optimal care paradigms for patients with these disorders.

Clinical aspects of hyperthyroidism, hypothyroidism, and thyroid screening in pregnancy

OBJECTIVE

To evaluate the peer-reviewed literature on hypothyroidism, hyperthyroidism, and thyroid autoimmunity in pregnancy.

METHODS

We review published studies on thyroid autoimmunity and dysfunction in pregnancy, the impact of thyroid disease on pregnancy, and discuss implications for screening.

RESULTS

Overt hyperthyroidism and hypothyroidism are responsible for adverse obstetric and neonatal events. Several studies of association suggest that either subclinical hypothyroidism or thyroid autoimmunity increase the risk of complications. One randomized controlled trial showed that pregnant women with subclinical hypothyroidism benefit from treatment in terms of obstetric and neonatal complications, whereas another study demonstrated no benefit in the intelligence quotient of babies born to women with subclinical hypothyroidism. Thyroid autoimmunity has been associated with increased rate of pregnancy loss, recurrent miscarriage, and preterm delivery.

CONCLUSION

Current guidelines agree that overt hyperthyroidism and hypothyroidism need to be promptly treated and that as potential benefits outweigh potential harm, subclinical hypothyroidism also requires substitutive treatment. The chance that women with thyroid autoimmunity may benefit from levothyroxine treatment to improve obstetric outcome is intriguing, but adequately powered randomized controlled trials are needed. The issue of universal thyroid screening at the beginning of pregnancy is still a matter of debate, and aggressive case-finding is supported.

Pregnancy and liver disease

Pregnancy associated liver diseases affect up to 3% of pregnant women and are the most frequent cause of liver dysfunction in pregnancy. When severe, they are associated with significant morbidity and mortality for both mother and infant. A rapid evaluation to distinguish them from non-pregnancy related liver dysfunction is essential, in order to facilitate appropriate management. Liver disease unrelated to pregnancy can present de novo in pregnancy, or pregnancy can occur in women with preexisting liver pathology (Table 1). Research and subsequent advances in medical care have resulted in improved but still not satisfactory maternal and fetal outcomes. In this review we provide an overview of the liver diseases specific to the pregnant state and an update on their pathogenesis, treatment and outcomes. The risks of pregnancy in women with pre-existent liver pathology is detailed and recent advances in our understanding of specific risks and outcomes are discussed.

Choriocarcinoma presenting with thyrotoxicosis

We describe a 26-year-old man with metastatic choriocarcinoma who presented with hyperthyroidism associated with elevated β-human chorionic gonadotropin (B-HCG) and respiratory failure secondary to diffuse lung metastasis. After the first cycle of chemotherapy, the concentration of B-HCG dramatically decreased and the patient became euthyroid, allowing us to discontinue antithyroid medications. The patient's hyperthyroidism was caused by stimulation of the thyroid gland by high B-HCG levels, as shown by the marked improvement of the patient's thyroid function panel after chemotherapy.

Gestational thyrotoxicosis, antithyroid drug use and neonatal outcomes within an integrated healthcare delivery system

BACKGROUND

Increasing attention has focused on the prevalence and outcomes of hyperthyroidism in pregnancy, given concerns for hepatotoxicity and embryopathy associated with antithyroid drugs (ATDs).

METHODS

In an integrated health care delivery system, we examined the prevalence of thyrotoxicosis and gestational ATD use (propylthiouracil [PTU] or methimazole [MMI]) in women with delivered pregnancies from 1996 to 2010. Birth outcomes were compared among all infants and those born to mothers with diagnosed thyrotoxicosis or ATD therapy during gestation, with examination of ATD-associated hepatotoxicity and congenital malformations in the latter subgroups.

RESULTS

Among 453,586 mother-infant pairs (maternal age 29.7±6.0 years, 57.1% nonwhite), 3.77 per 1000 women had diagnosed thyrotoxicosis and 1.29 per 1000 had gestational ATD exposure (86.5% PTU, 5.1% MMI, 8.4% both). Maternal PTU-associated hepatotoxicity occurred with a frequency of 1.80 per 1000 pregnancies. Infants of mothers with diagnosed thyrotoxicosis (odds ratio [OR] 1.28, 95% confidence interval [CI 1.05-1.55]) or gestational ATD use (OR 1.31 [1.00-1.72]) had an increased risk of preterm birth compared to those born to mothers without thyrotoxicosis or ATD. The risk of neonatal intensive care unit (NICU) admission was also higher with maternal thyrotoxicosis (OR 1.30 [1.07-1.59]) and ATD exposure (OR 1.64 [CI 1.26-2.13]), adjusting for prematurity. Congenital malformation rates were low and similar among infants born to mothers with thyrotoxicosis or ATD exposure (30-44 per 1000 infants).

CONCLUSIONS

Gestational ATD exposure occurred in 1.29 per 1000 mother-infant pairs while a much larger number had maternal diagnosed thyrotoxicosis but no drug exposure during pregnancy. Infants of mothers with gestational ATD use or diagnosed thyrotoxicosis were more likely to be preterm and admitted to the NICU. The rates of congenital malformation were low for mothers diagnosed with thyrotoxicosis and did not differ by ATD use. Among women with gestational PTU therapy, the frequency of PTU-associated hepatotoxicity was 1.8 per 1000 delivered pregnancies. These findings from a large, population-based cohort provide generalizable estimates of maternal and infant risks associated with maternal thyrotoxicosis and related pharmacotherapy.

Serum human chorionic gonadotropin levels and thyroid hormone levels in gestational transient thyrotoxicosis: Is the serum hCG level useful for differentiating between active Graves' disease and GTT?

Gestational transient thyrotoxicosis (GTT) is defined as transient thyrotoxicosis caused by the stimulating effect of human chorionic gonadotropin (hCG) during pregnancy. We attempted to identify the serum hCG level that causes GTT, and we compared the serum hCG levels and thyroid hormone levels of GTT patients according to whether they had a background of thyroid disease. We also evaluated serum hCG as a parameter for differentiating between active Graves' disease (GD) and GTT. We reviewed the 135 cases of pregnant women who came to our hospital to be evaluated for thyrotoxicosis during their 7th to 14th week of pregnancy, and their serum hCG level was measured at that time. Among the 135 pregnant women with thyrotoxicosis; 103 of the women had GTT, and the other 32 women had active GD. There were no correlations between their serum hCG levels and free thyroid hormone levels. There were no significant differences in thyroid hormone levels or hCG levels among the GTT groups with different thyroid disease backgrounds; i.e., the GTT group without thyroid disease, GTT group with chronic thyroiditis, GTT group with non-functioning thyroid nodules, and GTT group with GD in remission. The serum hCG level of the GTT group was significantly higher than in the active GD group, but it was not a good parameter for differentiating between the two groups. The FT3/FT4 ratio of the active GD was significantly higher than in GTT group, and was a better parameter for differentiation.

[Thyroid dysfunction during pregnancy]

Recent clinical practice guidelines on thyroid dysfunction and pregnancy have changed health care provided to pregnant women, although their recommendations are under constant revision. Trimester- and area-specific reference ranges for serum thyroid-stimulating hormone are required for proper diagnosis of hypothyroidism and hyperthyroidism. There is no doubt on the need of therapy for overt hypothyroidism, while therapy for subclinical hypothyroidism is controversial. Further research is needed to settle adverse effects of isolated hypothyroxinemia and thyroid autoimmunity. Differentiation between hyperthyroidism due to Graves' disease and the usually self-limited gestational transient thyrotoxicosis is critical. It is also important to recognize risk factors for postpartum thyroiditis. Supplementation with iodine is recommended to maintain adequate iodine nutrition during pregnancy and avoid serious consequences in offspring. Controversy remains about universal screening for thyroid disease during pregnancy or case-finding in high-risk women. Opinions of some scientific societies and recent cost-benefit studies favour universal screening. Randomized controlled studies currently under development should reduce the uncertainties that still remain in this area.

Associations between perfluoroalkyl acids (PFASs) and maternal thyroid hormones in early pregnancy: a population-based cohort study

BACKGROUND

Associations between perfluoroalkyl acids (PFASs) and human thyroid hormone levels remain unclear, especially during early pregnancy when small changes in maternal thyroid hormones can affect fetal brain development.

OBJECTIVES

To examine associations between maternal serum PFAS levels and maternal thyroid hormone levels in the early 2nd trimester of pregnancy.

METHODS

Participants were euthyroid pregnant women (n=152) enrolled in the Chemicals, Health and Pregnancy (CHirP) study based in Vancouver, Canada. Associations between maternal serum PFASs, including perfluorohexanesulfonate (PFHxS), perfluorononanoate (PFNA), perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) and repeated measures of maternal thyroid hormones, including free thyroxine (fT4), total thyroxine (TT4) and thyroid stimulating home (TSH) were examined using mixed effects linear models. Associations were considered in all women, then separately in women with high (≥ 9 IU/mL) vs normal (<9 IU/mL) levels of thyroid peroxidase antibody (TPOAb), a marker of autoimmune hypothyroidism (Hashimoto's disease).

RESULTS

Median PFAS concentrations (ng/mL) in maternal sera were 1.0 (PFHxS), 0.6 (PFNA), 1.7 (PFOA) and 4.8 (PFOS). PFASs were not associated with fT4, TT4 or TSH among women with normal TPOAb. However, among the 9% of women with high TPOAb (n=14), interquartile range (IQR) increases of PFASs were associated with a 46-69% increase in maternal TSH (95% CIs ranging from 8% to 123%) (PFNA, PFOA and PFOS only), and with a 3% to 7% decrease in maternal fT4 (95% CIs ranging from -18% to 5%) (all 4 PFASs). PFNA was also associated with higher maternal TSH in the whole sample.

CONCLUSIONS

PFASs were positively associated with TSH, and weakly negatively associated with fT4 in the subset of pregnant women with high TPOAb, which occurs in 6-10% of pregnancies. PFASs may exacerbate the already high TSH and low fT4 levels in these women during early pregnancy, which is a critical time of thyroid hormone-mediated fetal brain development. The clinical significance of these findings is not clear. We propose a "multiple hit hypothesis" to explain these findings; this hypothesis deserves evaluation in larger, more representative study samples.

Thyrotropin isoforms: implications for thyrotropin analysis and clinical practice

Serum thyrotropin (TSH) is considered the single most sensitive and specific measure of thyroid function in the general population owing to its negative logarithmic association with free triiodothyronine and free thyroxine concentrations. It is therefore often the test of choice for screening, diagnosis, and monitoring of primary hypothyroidism. Serum TSH concentrations can be analyzed quantitatively using third-generation immunoassays, whereas its bioactivity can be measured by TSH activity assays in cell culture. Theoretically, if serum TSH concentrations are directly related to TSH activity, the two tests should yield comparable results. However, on occasion, the results are discordant, with serum concentrations being higher than TSH biological activity. This review focuses on the dissociation between the clinical state and serum TSH concentrations and addresses clinically important aspects of TSH analysis.

The Use of TSH in Determining Thyroid Disease: How Does It Impact the Practice of Medicine in Pregnancy?

During the last four decades, there have been considerable advances in the efficacy and precision of serum thyroid function testing. The development of the third generation assays for the measurement of serum thyroid stimulating hormone (TSH, thyrotropin) and the log-linear relationship with free thyroxine (T4) established TSH as the hallmark of thyroid function testing. While it is widely accepted that TSH outside of the normal range is consistent with thyroid dysfunction, a vast multitude of additional factors must be considered before an accurate clinical diagnosis can be made. This is especially important during pregnancy, when the thyroid is under considerable additional pregnancy-related demands requiring significant maternal physiological changes. This paper examines serum TSH measurement in pregnancy and some associated potential confounding factors.

A case of alloimmune thrombocytopenia, hemorrhagic anemia-induced fetal hydrops, maternal mirror syndrome, and human chorionic gonadotropin-induced thyrotoxicosis

Fetal/neonatal alloimmune thrombocytopenia (FNAIT) can be a cause of severe fetal thrombocytopenia, with the common presentation being intracranial hemorrhage in the fetus, usually in the third trimester. A very unusual case of fetal anemia progressed to hydrops. This was further complicated by maternal Mirror syndrome and human chorionic gonadotropin-induced thyrotoxicosis. Without knowledge of etiology, and possibly due to associated cardiac dysfunction, fetal transfusion resulted in fetal demise. Subsequent testing revealed FNAIT as the cause of severe hemorrhagic anemia. In cases with fetal anemia without presence of red blood cell antibodies, FNAIT must be ruled out as a cause prior to performing fetal transfusion. Fetal heart may adapt differently to acute hemorrhagic anemia compared with a more subacute hemolytic anemia.

Quantitative ELISAs for serum soluble LHCGR and hCG-LHCGR complex: potential diagnostics in first trimester pregnancy screening for stillbirth, Down's syndrome, preterm delivery and preeclampsia

BACKGROUND

Soluble LH/hCG receptor (sLHCGR) released from placental explants and transfected cells can be detected in sera from pregnant women. To determine whether sLHCGR has diagnostic potential, quantitative ELISAs were developed and tested to examine the correlation between pregnancy outcome and levels of serum sLHCGR and hCG-sLHCGR complex.

METHODS

Anti-LHCGR poly- and monoclonal antibodies recognizing defined LHCGR epitopes, commerical anti-hCGbeta antibody, together with recombinant LHCGR and yoked hCGbeta-LHCGR standard calibrators were used to develop two ELISAs. These assays were employed to quantify serum sLHCGR and hCG-sLHCGR at first trimester human pregnancy.

RESULTS

Two ELISAs were developed and validated. Unlike any known biomarker, sLHCGR and hCG-sLHCGR are unique because Down's syndrome (DS), preeclampsia and preterm delivery are linked to both low (less than or equal to 5 pmol/mL), and high (equal to or greater than 170 pmol/mL) concentrations. At these cut-off values, serum hCG-sLHCGR together with PAPP-A detected additional DS pregnancies (21%) which were negative by free hCGbeta plus PAPP-A screening procedure. Therefore, sLHCGR/hCG-sLHCGR has an additive effect on the current primary biochemical screening of aneuploid pregnancies. More than 88% of pregnancies destined to end in fetal demise (stillbirth) exhibited very low serum hCG-sLHCGR(less than or equal to 5 pmol/mL) compared to controls (median 16.15 pmol/mL, n = 390). The frequency of high hCG-sLHCGR concentrations (equal to or greater than 170 pmol/mL) in pathological pregnancies was at least 3-6-fold higher than that of the control, suggesting possible modulation of the thyrotropic effect of hCG by sLHCGR.

CONCLUSIONS

Serum sLHCGR/hCG-sLHCGR together with PAPP-A, have significant potential as first trimester screening markers for predicting pathological outcomes in pregnancy.

Thyroid function in pregnancy

Iodine is required for the production of thyroid hormones. Normal thyroid function during pregnancy is important for both the mother and developing fetus. This review discusses the changes in thyroid physiology that occur during pregnancy, the significance of thyroid function tests and thyroid antibody titers assessed during pregnancy, and the potential obstetric complications associated with maternal hypothyroidism.

Management of Hyperthyroidism in Pregnancy: Results of a Survey among Members of the European Thyroid Association

BACKGROUND

An optimal management of maternal hyperthyroidism is important for positive pregnancy outcome, and to this end, the Endocrine Society published their guidelines in 2007. This survey aimed to investigate to what extent the clinical practice relating to the management of hyperthyroidism during pregnancy in Europe is uniform and consistent with the guidelines.

MATERIALS AND METHODS

We e-mailed an online questionnaire survey based on clinical case scenarios to 605 members of the European Thyroid Association. We analysed 190 responses from 28 European countries.

RESULTS

For a woman with newly diagnosed Graves' disease (GD) and wishing pregnancy, 78% of the responders would initiate antithyroid drugs (ATDs), while 22% would recommend definitive treatment with radioiodine or surgery. In case of a relapsed GD before pregnancy, 80% preferred definitive treatment. For a woman with newly diagnosed GD during pregnancy, 53% would treat with propylthiouracil, 12% with methimazole, and 34% with propylthiouracil initially and switch to methimazole after the first trimester. Responders used several combinations of tests to monitor the dose of ATDs, and the thyroid test results they targeted were inconsistent. For a lactating woman with GD, 68% would give ATDs without stopping lactation.

CONCLUSIONS

Variation in the clinical practices surrounding the management of hyperthyroid pregnant women in Europe still exists.

Thyrotoxicosis

Hyperthyroidism describes the sustained increase in thyroid hormone biosynthesis and secretion by a thyroid gland with increased metabolism. Although the use of radioiodine scanning serves as a useful surrogate that may help characterize the cause of thyrotoxicosis, it only indirectly addresses the underlying physiologic mechanism driving the increase in serum thyroid hormones. In this article, thyrotoxic states are divided into increased or decreased thyroid metabolic function. In addition to the diagnosis, clinical presentation, and treatment of the various causes of hyperthyroidism, a section on functional imaging and appropriate laboratory testing is included.

Thyrotoxic crisis associated with gestational trophoblastic disease

BACKGROUND AND OBJECTIVES

Human chorionic gonadotropin (HCG) and thyrotrophic hormone (TSH) have analogies in their structures, as well as in their receptors. The high levels of HCG seen in gestational trophoblastic diseases may induce secondary hyperthyroidism. The objective of this report was to present a case in which the administration of iodinated contrast triggered a thyrotoxic crisis.

CASE REPORT

Patient with complete hydatidiform mole who was admitted to the operating room with severe vaginal bleeding after a tomographic exam with iodinated contrast. During anesthetic induction, the patient presented symptoms compatible with thyrotoxic crisis.

CONCLUSIONS

The incidence of severe presentations associated with gestational trophoblastic disease tends to decrease with early diagnosis. Still, the anesthesiologist should be aware of the possibility of those patients developing thyrotoxic crisis.

Overt hyperthyroidism and hypothyroidism during pregnancy

The present manuscript provides a definition for, and evaluates the prevalence and maternal/fetal/child impact of, overt hyperthyroidism and overt hypothyroidism. The prevalence of overt hyperthyroidism is 0.5% and the prevalence of overt hyperthyroidism is 0.3%. Overt maternal hyperthyroidism is associated with heart failure, preeclampsia, preterm delivery, still birth, and neonatal mortality. Overt maternal hypothyroidism is associated with preeclampsia, gestational hypertension, cretinism, fetal deaths, and spontaneous abortion. A cost-effective analysis for screening and treating overt thyroid disease during pregnancy is warranted.

Transient non-autoimmune hyperthyroidism of early pregnancy

It is characterized by chemical and sometimes clinical hyperthyroidism, without evidence of thyroid autoimmunity that resolves spontaneously by 16 weeks gestation without significant obstetrical complications.

Contemporary approaches to hyperemesis during pregnancy

PURPOSE OF REVIEW

Nausea and vomiting of pregnancy (NVP) affects 90% of pregnant women and its impact is often underappreciated. Hyperemesis gravidarum, the most severe end of the spectrum, affects 0.5-2% of pregnancies. The pathogenesis of this condition remains obscure and its management has largely been empirical. This review aims to provide an update on advances in pregnancy hyperemesis focusing on papers published within the past 2 years.

RECENT FINDINGS

The cause of hyperemesis is continuing to be elaborated. Recent data attest to the effectiveness of the oral doxylamine-pyridoxine in NVP. Follow-up data of children exposed in early pregnancy to doxylamine-pyridoxine for NVP are reassuring. Evidence is increasing for ginger as an effective herbal remedy for NVP. Metoclopramide is effective in NVP and hyperemesis gravidarum, with a good balance of efficacy and tolerability. A recent large-scale study on first trimester exposure to metoclopramide is reassuring of its safety. Evidence is emerging for the treatment of acid reflux to ameliorate NVP. The role of corticosteroids for hyperemesis gravidarum remains controversial. Transpyloric feeding may be warranted for persistent weight loss, despite optimal antiemetic therapy.

SUMMARY

Women with significant NVP should be identified so that they can be safely and effectively treated.

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.