Clinical analysis of 65 cases of hyperemesis gravidarum with gestational transient thyrotoxicosis

Risk factors associated with gestational transient thyrotoxicosis and their effects on the pregnancy course

OBJECTIVE

To investigate the clinical characteristics of patients with gestational transient thyrotoxicosis and its possible impacts on pregnancy.

METHODS

This retrospective study included pregnant women with gestational transient thyrotoxicosis who were admitted to our endocrinology outpatient clinic from June 2020 to March 2023. Patients with other causes of thyrotoxicosis, such as Graves' disease, toxic nodular goiter, and subacute thyroiditis, were excluded.

RESULTS

The study included 50 pregnant women who met the inclusion criteria and whose data could be accessed. Two pregnant women were diagnosed with gestational diabetes, and two pregnancies resulted in abortion. We observed that thyroid-stimulating hormone levels normalized to euthyroid values at a mean gestational age of 18.3 ± 3.7 weeks. The mean gestational age at birth was 38 ± 1.8 weeks. The frequency of preterm labor, defined as delivery before 37 weeks, was 10% (n = 5). Sinus rhythm was observed in 87% of the electrocardiograms obtained during thyrotoxicosis, while sinus tachycardia was detected in four and sinus arrhythmia in two cases. Thyroid nodules were observed in 23 (47.9%) of 48 cases in which ultrasonography was performed during thyrotoxicosis. Discussion: This retrospective study, including 50 pregnant women with gestational transient thyrotoxicosis, found no increase in the rate of serious obstetric complications such as eclampsia/preeclampsia, gestational diabetes, preterm labor, or abortion. Notably, in a detailed examination of electrocardiograms, which has not been done in previous studies, we did not detect any serious, life-threatening arrhythmias, although tachycardia was observed.

An Unusual and Severe Thyrotoxicosis in a Twin Pregnancy: Fortune Favors the Brave

Graves' disease (GD) and gestational transient thyrotoxicosis (GTT) are the most common causes of thyrotoxicosis during pregnancy, with prevalence ranging from 0.1% to 1% and from 1% to 3%, respectively. Hyperthyroidism during pregnancy can have severe consequences if not promptly recognized and treated. Even more severe, if possible, is the thyroid storm, a life-threatening complication of hyperthyroidism, characterized by severe and dramatic clinical manifestations of thyrotoxicosis. No prior history of thyroid disease, absence of GD stigmata, negative thyrotropin (TSH) receptor antibody levels, serum human chorionic gonadotropin (hCG) higher on average, and symptoms of emesis may lead to the diagnosis of GTT. Few cases of thyroid storm during pregnancy are reported in literature, mainly due to gestational trophoblastic disease. We report a rare and severe case of thyroid storm in a 24-year-old woman at 15 weeks' gestation with twins, likely due to GTT, precipitated by acute myocarditis. Initially presenting with weakness, vomiting, and sinus tachycardia, the patient rapidly deteriorated into a life-threatening condition characterized by hypokalemia, myocardial injury, and severe thyrotoxicosis. Cardiac imaging later revealed acute myocarditis. Thyroid function stabilized at the end of the pregnancy, allowing discontinuation of methimazole. Both fetuses were delivered via emergency cesarean section at 36 weeks, with no significant congenital abnormalities. This case highlights the complexity of diagnosing and managing hyperthyroidism in twin pregnancies, particularly in the context of hyperemesis gravidarum (HG).

The IRIS clinic: A Protocol for a mixed-methods study evaluating the management of Hyperemesis Gravidarum

Background

Hyperemesis Gravidarum (HG) is a severe form of nausea and vomiting in pregnancy that affects 0.3-3% of women and has profound nutritional, physical and psychological consequences. Research is lacking regarding the most effective management of the condition. In response to patient feedback, a multidisciplinary HG day-case service (IRIS Clinic) was launched in 2020 at The National Maternity Hospital, Ireland. The clinic provides routine, day-case care in a comfortable space with pre-booked appointments. The MDT involves midwives, dietitians, perinatal mental health, obstetrics and pharmacy, and the nature of the clinic enables peer-to-peer support. As this clinic is the first of its kind in Ireland, we aim to assess its effectiveness and feasibility, and suggest recommendations for improvement.

Methods

This is a sequential, mixed-methods study that commenced in August 2021. The prospective arm of the study is ongoing and involves enrolling women (n = 50) who are attending the IRIS clinic. Data are collected on first admission (pre-intervention) and approximately 8 weeks' later (post-intervention) relating to symptoms of HG, well-being, food tolerances, quality of life and nutritional intake. Qualitative, semi-structured interviews will be conducted to evaluate women's experiences of attending the clinic. The retrospective arm of the study will be a chart review (n = 200) of women diagnosed with HG to describe assessments, treatments and pregnancy and birth outcomes.

Conclusion

The IRIS clinic has the potential to improve pregnancy outcomes and nutritional status among women with HG. If found to be effective and feasible, the model for this clinic could be replicated elsewhere.

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.

Gestational Transient Thyrotoxicosis Complicated by Thyroid Storm in a Patient With Hyperemesis Gravidarum

We describe a patient with gestational transient thyrotoxicosis (GTT) associated with hyperemesis gravidarum (HG) in a twin gestation complicated by thyroid storm resulting in intrauterine fetal demise. GTT is a well-documented complication of the first trimester of pregnancy that may affect up to 60% of pregnancies with HG. Typically, GTT is not associated with unfavorable maternal or fetal outcomes and has a spontaneous resolution. Aside from supportive care, the use of antithyroid drugs (ATD) in GTT is not regularly recommended. Although to our knowledge one similar case has been reported in the literature, the incidence of thyroid storm in GTT has not yet been established. Our case highlights that, although rare, GTT may be complicated by thyroid storm resulting in adverse maternal and fetal outcomes. Our case further suggests that consideration of ATD use in GTT should be given in pregnancies with higher serum human chorionic gonadotropin (hCG) concentration as occurs in HG and multiple pregnancies.

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.

Is hyperemesis gravidarum associated with transient hyperthyroidism? A systematic review and meta-analysis

Emerging evidence suggests an association of hyperemesis gravidarum (HG) with transient hyperthyroidism and high HCG levels. For synthesizing the current evidence to determine the association between HG with hormones related to thyroid function, a comprehensive systematic search was performed in the electronic databases comprised Medline, Web of Science, Scopus, Embase, ProQuest, and Cochrane Library up to December 2021. All published observational studies that evaluated the association of hyperemesis gravidarum with transient hyperthyroidism were investigated considering the PICO method. The standardized Joanna Briggs Institute Meta-Analysis of Statistics, Assessment, and Review Instrument were applied to appraise the included studies. Twenty-nine studies consisted of 6525 women included in the systematic review. Among them, 28 studies with 2446 participants were included in the meta-analysis. There were significant associations of HG with fT3 (MD: 1.31 pg/mL, 95% CI: 0.61 to 2.01), fT4 (MD: 1.95 ng/dL, 95% CI: 1.17 to 2.73), TSH (MD: -1.22μIU/mL, 95% CI: -1.75 to -0.68), TT4 (MD: 0.56 nmol/L, 95% CI:-0.43 to 1.24), and HCG (MD: 1.90IU/L, 95% CI: 0.497 to 3.301). In conclusion, the serum levels of fT3, fT4, and TT4 increased but TSH decreased significantly in women with compared without HG, indicating the significant association of HG with GTT.

Anti-Mullerian hormone levels in spontaneous pregnancies with hyperemesis gravidarum

We investigated the serum anti-Mullerian hormone (AMH), oestrogen and progesterone levels in spontaneously conceiving pregnant women, diagnosed for hyperemesis gravidarum (HG), in the first trimester. Pregnant women admitted at Hospital between 5 and 12 gestational weeks and treated for HG were compared, in this prospective case-control study, to a control group. The serum AMH, oestradiol, and progesterone values of both groups were evaluated and compared, and potential correlations were calculated. The serum AMH values were significantly higher in the HG group than the control group (3.15 ± 1.51 ng/mL vs. 2.27 ± 1.20 ng/mL; p = 0.012). No significant difference in the two groups was about serum oestradiol and progesterone values (p = 0.264, p = 0.235). In the HG group, there was no significant correlation between AMH and oestradiol (p = 0.570). However, a significant positive correlation was determined between AMH and progesterone (p = 0.050). The area under the ROC curve (AUC) was 0.669 and the cut-off value was 2.65 ng/ml with sensitivity of 58.3% and specificity of 66.7% for AMH in pregnant women with HG. A correlation between AMH high values and unexplained HG was detected in spontaneous pregnancies in the first trimester. High AMH levels may play a role in HG etiopathogenesis, especially in pregnant women with low progesterone levels.Impact statementWhat is already known on this subject? Aetiological causes of Hyperemesis gravidarum (HG) include hormonal, immunological, genetic, and psychological issues. However, no conclusive etiopathogenesis to explain the pathophysiological mechanism of HG has been stated.What do the results of this study add? Authors focussed on investigation a possible correlation between pregnant hormones and the HG pathogenesis, prevalent in the first trimester, when hormones are produced by either the placenta or corpus luteum. High anti-Mullerian hormone (AMH) levels may play a role in HG etiopathogenesis, especially in pregnant women with low progesterone levels.What are the implications of these findings for clinical practice and/or further research? A serum AMH level of ≥2.65 mg/mL could be predictive for the development of HG in the first trimester of a spontaneous pregnancy. Basing on these findings, more selective pharmacological treatments could be administrated to these patients.

Thyroid Storm Caused by Hyperemesis Gravidarum

Background

Transient thyrotoxicosis has been documented in the setting of hyperemesis gravidarum (HG) with elevated human chorionic gonadotropin (hCG) levels. Thyroid storm in pregnancy is rarer and typically associated with autoimmune hyperthyroidism. We described thyroid storm in a primigravid 18-year-old patient due to hCG level elevation secondary to HG, which resolved in the second trimester of pregnancy.

Case Report

Our patient presented with vomiting, hyperthyroidism, and cardiac and renal dysfunction at 16 weeks’ gestation. She was clinically found to have a thyroid storm, with undetectable thyroid-stimulating hormone (TSH) and a free thyroxine level of >6.99 ng/dL. The hCG level was elevated at 246 030 mIU/L (9040-56 451 mIU/L). She was treated with methimazole, saturated solution potassium iodide, and propranolol. Because thyroid autoantibodies were absent, thyroid ultrasound yielded normal results, and thyroid function testing results rapidly improved as the hCG level decreased, the medications were tapered and ultimately discontinued by day 10 of hospitalization. The thyroid function remained normal after discharge.

Discussion

Because hCG and TSH have identical alfa subunits and similar beta subunits, hCG can bind to the TSH receptor and stimulate thyroxine production. The hCG level peaks at around 8-14 weeks of gestation, correlating with decreased TSH levels in this same time frame. This case emphasizes the relevant physiology and importance of timely and thorough evaluation to determine the appropriate management, prognosis, and follow-up for patients with thyroid storm in the setting of HG.

Conclusion

Although transient thyrotoxicosis is documented in patients with HG, thyroid storm is rare, and our case illustrates a severe example of these comorbidities.

Life-threatening complications of hyperemesis gravidarum

Hyperemesis gravidarum (HG) refers to severe nausea and emesis noted during pregnancy. However, no consensus exists on the specific diagnostic criteria that can be used for this condition. The aim of the present systematic review was to summarize the available evidence regarding the severe complications observed during HG with a heightened risk of fatality. A systematic search was conducted on PubMed, Cochrane Library, EMBASE and WILEY databases for the relevant publications regarding the severe and life-threatening complications of HG. The search terms were as follows: '(Hyperemesis gravidarum)' AND ('complications' OR 'severe' OR 'adverse pregnancy outcomes' OR 'stroke' OR 'seizures' OR 'Wernicke's encephalopathy' OR 'arrhythmias' OR 'pneumomediastinum' OR 'coagulopathy' OR 'electrolytic imbalance'). Abstracts, conference presentations, letters to the editor, studies written in languages other than English and editorials were all excluded. This search identified 43 studies analyzing life-threatening complications of HG, of which 11, seven, eight and 17 articles analyzed neurological, cardiovascular, thoracic and systemic complications, respectively. Reports on life-threatening complications were exceptionally rare in HG. The most frequent severe complications noted were Wernicke's encephalopathy, electrolyte imbalance and vitamin K deficiency. The low mortality rate for patients with HG over the last decade could be explained by the high efficiency of modern therapy, and the precise management of every complication according to current guidelines.

Thyroid-stimulating hormone and free thyroxine fail to predict the severity and clinical course of hyperemesis gravidarum: A prospective cohort study

Introduction

Little is known about the pathophysiology of hyperemesis gravidarum (HG). Proposed underlying causes are multifactorial and thyroid function is hypothesized to be causally involved. In this study, we aimed to assess the utility of thyroid‐stimulating hormone (TSH) and free thyroxine (FT4) as a marker and predictor for the severity and clinical course of HG.

Material and methods

We conducted a prospective cohort study including women admitted for HG between 5 and 20 weeks of gestation in 19 hospitals in the Netherlands. Women with a medical history of thyroid disease were excluded. TSH and FT4 were measured at study entry. To adjust for gestational age, we calculated TSH multiples of the median (MoM). We assessed HG severity at study entry as severity of nausea and vomiting (by the Pregnancy Unique Quantification of Emesis and nausea score), weight change compared with prepregnancy weight, and quality of life. We assessed the clinical course of HG as severity of nausea and vomiting and quality of life 1 week after inclusion, duration of hospital admissions, and readmissions. We performed multivariable regression analysis with absolute TSH, TSH MoMs, and FT4.

Results

Between 2013 and 2016, 215 women participated in the cohort. TSH, TSH MoM, and FT4 were available for, respectively, 150, 126, and 106 of these women. Multivariable linear regression analysis showed that lower TSH MoM was significantly associated with increased weight loss or lower weight gain at study entry (ΔKg; β = 2.00, 95% CI 0.47‐3.53), whereas absolute TSH and FT4 were not. Lower TSH, not lower TSH MoM or FT4, was significantly associated with lower nausea and vomiting scores 1 week after inclusion (β = 1.74, 95% CI 0.36‐3.11). TSH and FT4 showed no association with any of the other markers of the severity or clinical course of HG. Twenty‐one out of 215 (9.8%) women had gestational transient thyrotoxicosis. Women with gestational transient thyrotoxicosis had a lower quality of life 1 week after inclusion than women with no gestational transient thyrotoxicosis (p = 0.03).

Conclusions

Our findings show an inconsistent role for TSH, TSH MoM, or FT4 at time of admission and provide little guidance on the severity and clinical course of HG.

Hyperemesis Gravidarum: Strategies to Improve Outcomes

Hyperemesis gravidarum (HG) is a debilitating and potentially life-threatening pregnancy disease marked by weight loss, malnutrition, and dehydration attributed to unrelenting nausea and/or vomiting; HG increases the risk of adverse outcomes for the mother and child(ren). The complexity of HG affects every aspect of a woman's life during and after pregnancy. Without methodical intervention by knowledgeable and proactive clinicians, life-threatening complications may develop. Effectively managing HG requires an understanding of both physical and psychosocial stressors, recognition of potential risks and complications, and proactive assessment and treatment strategies using innovative clinical tools.

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.

Nausea and vomiting of pregnancy and hyperemesis gravidarum

Nausea and vomiting of pregnancy (NVP) is a common condition that affects as many as 70% of pregnant women. Although no consensus definition is available for hyperemesis gravidarum (HG), it is typically viewed as the severe form of NVP and has been reported to occur in 0.3-10.8% of pregnant women. HG can be associated with poor maternal, fetal and child outcomes. The majority of women with NVP can be managed with dietary and lifestyle changes, but more than one-third of patients experience clinically relevant symptoms that may require fluid and vitamin supplementation and/or antiemetic therapy such as, for example, combined doxylamine/pyridoxine, which is not teratogenic and may be effective in treating NVP. Ondansetron is commonly used to treat HG, but studies are urgently needed to determine whether it is safer and more effective than using first-line antiemetics. Thiamine (vitamin B1) should be introduced following protocols to prevent refeeding syndrome and Wernicke encephalopathy. Recent advances in the genetic study of NVP and HG suggest a placental component to the aetiology by implicating common variants in genes encoding placental proteins (namely GDF15 and IGFBP7) and hormone receptors (namely GFRAL and PGR). New studies on aetiology, diagnosis, management and treatment are under way. In the next decade, progress in these areas may improve maternal quality of life and limit the adverse outcomes associated with HG.

Management of Endocrinopathies in Pregnancy: A Review of Current Evidence

Pregnancy in women with associated endocrine conditions is a therapeutic challenge for clinicians. These disorders may be common, such us thyroid disorders and diabetes, or rare, including adrenal and parathyroid disease and pituitary dysfunction. With the development of assisted reproductive techniques, the number of pregnancies with these conditions has increased. It is necessary to recognize symptoms and correct diagnosis for a proper pharmacotherapeutic management in order to avoid adverse side effects both in mother and fetus. This review summarizes the pharmacotherapy of these clinical situations in order to reduce maternal and fetal morbidity.

Ambulatory versus inpatient management of severe nausea and vomiting of pregnancy: a randomised control trial with patient preference arm

OBJECTIVE

To determine whether ambulatory (outpatient (OP)) treatment of severe nausea and vomiting of pregnancy (NVP) is as effective as inpatient (IP) care.

DESIGN

Non-blinded randomised control trial (RCT) with patient preference arm.

SETTING

Two multicentre teaching hospitals in London.

PARTICIPANTS

Women less than 20 weeks' pregnant with severe NVP and associated ketonuria (>1+).

METHODS

Women who agreed to the RCT were randomised via web-based application to either ambulatory or IP treatment. Women who declined randomisation underwent the treatment of their choice in the patient preference trial (PPT) arm. Treatment protocols, data collection and follow-up were the same for all participants.

MAIN OUTCOME MEASURES

Primary outcome was reduction in Pregnancy Unique Quantification of Emesis (PUQE) score 48 hours after starting treatment. Secondary outcome measures were duration of treatment, improvement in symptom scores and ketonuria at 48 hours, reattendances within 7 days of discharge and comparison of symptoms at 7 days postdischarge.

RESULTS

152/174 eligible women agreed to participate with 77/152 (51%) recruited to the RCT and 75/152 (49%) to the PPT.Patients were initially compared in four groups (randomised IP, randomised OP, non-randomised IP and non-randomised OP). Comprehensive cohort analysis of participants in the randomised group (RCT) and non-randomised group (PPT) did not demonstrate any differences in patient demographics or baseline clinical characteristics. Pooled analysis of IP versus OP groups showed no difference in reduction in PUQE score at 48 hours (p=0.86). There was no difference in change in eating score (p=0.69), drinking score (p=0.77), well-being rating (p=0.64) or reduction in ketonuria (p=0.47) at 48 hours, with no difference in duration of index treatment episode (p=0.83) or reattendances within 7 days (p=0.52).

CONCLUSIONS

Ambulatory management is an effective direct alternative to IP management of severe NVP. The trial also demonstrated that many women requiring treatment for severe NVP have strong preferences regarding treatment setting, which may need to be considered by care providers, especially given the psychological impact of severe NVP.

TRIAL REGISTRATION NUMBER

http://www.isrctn.com/ISRCTN24659467 (March 2014).

Nausea and vomiting of pregnancy - What's new?

Nausea and vomiting of pregnancy (NVP) is one of the most common disorders of pregnancy. The symptoms occur predominantly during the first trimester, although in a subgroup of patients they can continue throughout the entire pregnancy and can affect the woman's quality of life. A small percentage of women develop a severe form of NVP called hyperemesis gravidarum (HG) that if left untreated may lead to significant maternal morbidity and adverse birth outcomes. Overall, the morbidity in pregnant women with NVP is significant, although it tends to be underestimated. The pathogenesis of NVP remains unclear, but there is consensus that the disorder is multifactorial and that various genetic, endocrine and infectious factors may be involved. The treatment of NVP can be challenging as the optimal targets for therapy are not known. Currently, the therapy used depends on the severity of the disorder and it is focused on improving the symptoms while minimizing risks to mother and fetus. Therapies range from dietary changes, pharmacologic treatment or hospitalization with intravenous fluid replacement and nutrition therapy. The aims of this review are 1) to provide an overview of NVP, 2) to present possible links between the most important factors associated with the pathogenesis of NVP and 3) to discuss the effectiveness and safety of the pharmacologic and non-pharmacologic options available to treat this disorder.

The Risk of Preeclampsia According to High Thyroid Function in Pregnancy Differs by hCG Concentration

CONTEXT

During pregnancy, there is an increased demand for thyroid hormone. The pregnancy hormone human chorionic gonadotropin (hCG) is an important physiological stimulator of thyroid function. Already high-normal maternal free T₄ concentrations are associated with a higher risk of preeclampsia.

OBJECTIVE

The objective of the investigation was to study our hypothesis that hCG concentrations can distinguish a physiological form of high thyroid function from a more pathological form of high thyroid function and that the risk of preeclampsia would differ accordingly.

DESIGN

TSH, free T₄, hCG, or thyroperoxidase antibody concentrations were determined in pregnant women participating in a population-based prospective cohort study.

SETTING

The study was conducted in the general community.

PARTICIPANTS

A nonselected sample of 5146 pregnant women participated in the study.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURE(S)

Preeclampsia was measured.

RESULTS

Women with high hCG-associated high thyroid function did not have a higher risk of preeclampsia than women with normal thyroid function. In contrast, women with low hCG and high thyroid function had a 3.4- to 11.1-fold higher risk of preeclampsia. These risk estimates were amplified in women with a high body mass index. Women with a low hCG and suppressed TSH (<0.10 mU/L) had a 3.2- to 8.9-fold higher risk of preeclampsia. hCG was not associated with preeclampsia, and results remained similar after exclusion of thyroperoxidase antibody-positive women.

CONCLUSION

This study suggests that, in contrast to women with a high hCG associated high thyroid function, women with low hCG and high thyroid function during pregnancy are at a higher risk of developing preeclampsia. The additional measurement of hCG may therefore help to distinguish a more pathological form of high thyroid function and women at a high risk of preeclampsia.

Graves' Disease Pharmacotherapy in Women of Reproductive Age

Graves' disease is an autoimmune disorder in which inappropriate stimulation of the thyroid gland results in unregulated secretion of thyroid hormones resulting in hyperthyroidism. Graves' disease is the most common cause of autoimmune hyperthyroidism during pregnancy. Treatment options for Graves' disease include thioamide therapy, partial or total thyroidectomy, and radioactive iodine. In this article, we review guideline recommendations for Graves' disease treatment in women of reproductive age including the recent guideline from the American College of Obstetricians and Gynecologists. Controversy regarding appropriate thioamide therapy before, during, and after pregnancy is reviewed. Surgical and radioactive iodine therapy considerations in this patient population are also reviewed. In patients who may find themselves pregnant during therapy or develop Graves' disease during their pregnancy, consideration should be given to the most appropriate treatment course for the mother and fetus. Thioamide therapy should be used with either propylthiouracil or methimazole at appropriate doses that target the upper range of normal to slightly hyperthyroid to avoid creating hypothyroidism in the fetus. Consideration should also be given to the adverse effects of thioamide, such as agranulocytosis and hepatotoxicity, with appropriate patient consultation regarding signs and symptoms. Individuals who wish to breastfeed their infants while taking thioamide should receive the lowest effective dose. Surgery should be reserved for extreme cases and limited to the second trimester, if possible. Radioactive iodine therapy may be used in nonpregnant individuals, with limited harm to future fertility. Radioactive iodine therapy should be withheld in pregnant women and those who are actively breastfeeding. Clinicians should keep abreast of developments in clinical trials and evidence-based recommendations regarding Graves' disease in reproductive-age women for any changes in evidence-based practice.

Thyroid disorders during pregnancy and postpartum

An awareness of the gestational changes to thyroid physiology and the impact of uncontrolled thyroid disease on pregnancy and infant outcome is essential for the successful management of hypothyroidism and hyperthyroidism. This review summarizes strategies for the management of thyroid disease in pregnancy and post partum, and it highlights areas where there is still a lack of consensus.