Recurrent hyperthyroidism in consecutive pregnancies characterized by hyperemesis

Maternal hypothyroidism may be associated with CHD in offspring

OBJECTIVES

This study tested whether mothers with maternal hypothyroidism have increased odds of CHD in their offspring, and examined the relationship between CHD, maternal thyroid function, and nausea and vomiting in pregnancy.

BACKGROUND

Maternal hypothyroidism increases the risk for foetal demise and prematurity and can have a negative impact on neurodevelopment. Prior studies have postulated a relationship between maternal thyroid function, CHD, and maternal nausea and vomiting in pregnancy.

METHODS

A cross-sectional case-control study was conducted over a 17-month period to obtain a history of maternal thyroid status and nausea and vomiting in pregnancy. Paediatric echocardiograms were evaluated for CHD by a blinded paediatric cardiologist. Logistic regression analysis was performed to examine the association between CHD and maternal hypothyroidism.

RESULTS

Of the 998 maternal-child pairs, 10% (98/998) of the mothers reported a history of prenatal hypothyroidism. The overall prevalence of CHD in the study sample was 63% (630/998). Mothers with a history of hypothyroidism were significantly more likely to have offspring with CHD compared with mothers without a history of hypothyroidism (72 versus 62%; p=0.04). The adjusted odds ratio (95% confidence interval) of CHD in offspring associated with reported maternal hypothyroidism was 1.68 (1.02-2.78).

CONCLUSION

This study suggests that maternal hypothyroidism is a risk factor for the development of CHD. Further prospective investigations are necessary to confirm this association and delineate pathogenic mechanisms.

The Brazilian consensus for the diagnosis and treatment of hyperthyroidism: recommendations by the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism

INTRODUCTION

Hyperthyroidism is characterized by increased synthesis and release of thyroid hormones by the thyroid gland. Thyrotoxicosis refers to the clinical syndrome resulting from excessive circulating thyroid hormones, secondary to hyperthyroidism or due to other causes. This article describes evidence-based guidelines for the clinical management of thyrotoxicosis.

OBJECTIVE

This consensus, developed by Brazilian experts and sponsored by the Department of Thyroid Brazilian Society of Endocrinology and Metabolism, aims to address the management, diagnosis and treatment of patients with thyrotoxicosis, according to the most recent evidence from the literature and appropriate for the clinical reality of Brazil.

MATERIALS AND METHODS

After structuring clinical questions, search for evidence was made available in the literature, initially in the database MedLine, PubMed and Embase databases and subsequently in SciELO - Lilacs. The strength of evidence was evaluated by Oxford classification system was established from the study design used, considering the best available evidence for each question.

RESULTS

We have defined 13 questions about the initial clinical approach for the diagnosis and treatment that resulted in 53 recommendations, including the etiology, treatment with antithyroid drugs, radioactive iodine and surgery. We also addressed hyperthyroidism in children, teenagers or pregnant patients, and management of hyperthyroidism in patients with Graves' ophthalmopathy and various other causes of thyrotoxicosis.

CONCLUSIONS

The clinical diagnosis of hyperthyroidism usually offers no difficulty and should be made with measurements of serum TSH and thyroid hormones. The treatment can be performed with antithyroid drugs, surgery or administration of radioactive iodine according to the etiology of thyrotoxicosis, local availability of methods and preferences of the attending physician and patient.

Hyperemesis gravidarum and fetal gender: a retrospective study

This retrospective study of 9,980 women who delivered at the James Paget Hospital, Norfolk, UK, over 5 years, aimed to primarily determine whether the incidence of hyperemesis gravidarum (HG) is higher in the presence of a female fetus. The results showed that more women with HG had a female fetus compared with women without HG. Also found was that heavy ketonuria was more prevalent in women with a female fetus compared with women with a male fetus, and the mean number of admissions per woman was also higher in women with a female fetus compared with women with a male fetus. It can be concluded that women presenting with HG are more likely to have a female fetus and that women with HG and a female fetus tend to a higher level of ketonuria and an increased number of hospital admissions.

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.

[Thyroid and pregnancy]

Pregnancy is associated with an increased requirement of hormone secretion by the thyroid, within the first weeks after conception. To this greater demand to occurs, pregnancy induces a series of physiological changes that affect thyroid function and, consequently, the tests of glandular function. For normal pregnant women living in areas with a sufficient supply of iodine, this challenge regarding the adjustment of thyroid hormone releases to this new state of equilibrium and its maintenance until the end of pregnancy it meets no difficulties. However, among women with impaired thyroid function due to some thyroid disease or among women residing in areas with an insufficient iodine supply, this does not occur. The management of thyroid dysfunction during gestation requires special considerations, since both hypothyroidism and hyperthyroidism can lead to maternal and fetal complications. In addition, thyroid nodules are detected at reasonable frequency among pregnant women, a fact that requires a differential diagnosis between benign and malignant growths during the pregnancy itself.

Pregnancy-associated liver disorders

Liver disorders associated with pregnancy include hyperemesis gravidarum (HG), intrahepatic cholestasis of pregnancy (ICP), preeclampsia, syndrome of hemolysis, elevated liver enzymes and low platelets (HELLP), and acute fatty liver of pregnancy (AFLP). These conditions are relatively common and unique to pregnancy and are more likely to occur at certain terms of gestation specific to each condition. They can be associated with significant maternal and fetal morbidity and mortality. Although managing such patients may be very challenging, spontaneous resolution of the disease occurs shortly after termination of the pregnancy, usually without hepatic sequellae. Early diagnosis and timely treatment is a key to therapeutic success. This article explores the clinical features, pathophysiology, and management of these disorders.

Thyroid disease and other endocrine disorders in pregnancy

Endocrine disorders, in particular, thyroid disorders, are common in pregnancy. The endocrine adaptation to pregnancy, need for adequate iodine supplementation, and thyroxine replacement are presented. In addition, autoimmune diseases of the thyroid and pituitary that may occur subsequent to the immune changes of pregnancy and the postpartum period are discussed. A brief account of the presentation of other endocrine disorders (ie, pituitary,parathyroid, calcium, adrenal and gonadal disorders) also is given, along with their evaluation and management.

Hyperemesis gravidarum: current concepts and management

Hyperemesis gravidarum is a common problem for an obstetrician. Though nausea and vomiting are quite common in pregnancy, hyperemesis is found in only 1-20 patients per 1000. In this practical review, a general outline of the syndrome, its relation to the gastrointestinal system and thyroid, mild and rare severe complications, and conventional treatment versus newer options are discussed.

Hypothetical framework for a relationship between maternal thyroid function, nausea and vomiting of pregnancy, and congenital heart disease

Our objective was to investigate whether a relationship exists among maternal thyroid function, nausea and vomiting of pregnancy, and congenital heart disease. A Medline search from 1966 to the present was conducted to look for reports on the existence of this relationship. The results were supplemented by abstract searches and personal communication with relevant authors. Our search found independent evidence that maternal hyperthyroidism is related to increased rates of nausea and vomiting of pregnancy, which in turn is significantly related to a decrease in the incidence of congenital heart disease. Early evidence indicates that the converse may be true: maternal hypothyroidism and thyroid replacement therapy are associated with an increase in congenital heart disease in children. The potential relationship between maternal thyroid function, nausea and vomiting of pregnancy, and thyroid replacement therapy needs further study. We propose a case-control study of children presenting for echocardiography to elicit specific information regarding the pregnancy.