Autoimmune thyroid disease during pregnancy

Relevance of systematic anti-nuclear antibodies testing after obstetrical complications

Adverses pregnancy outcomes are commonly encountered with autoimmune disease (AID). Although anti-nuclear antibodies (ANA) are often present several years before AID diagnosis, the importance of ANA testing has not been evaluated in this context. The objective of this study was to determine if ANA discovery after obstetrical complications is associated with a diagnosis of AID and improves the prognosis of subsequent pregnancies. All patients presented at the multidisciplinary board meeting (MBM) "Thrombophilia and Pregnancy", whose ANA were discovered after an obstetrical complication, were included in a multicenter descriptive study. All patients were referred to an internal medicine consultation for diagnosis. Data were collected retrospectively by computer chart analysis and updated by phone. A total of 404 patients were included, of which 50 (12.4 %) had a diagnosis of AID related to ANA. Patients with AID had higher ANA levels (p < 0.001), with more frequent specificity (26%, versus 6.7%, p < 0.0001), and more often persistent (84% versus 30.8%, p < 0.0001) compared to patients without AID. Subsequent pregnancy outcomes were not significantly affected by ANA levels and AID diagnoses. Our study shows that the discovery of ANA after obstetrical complications may lead to an early diagnosis of AID. It makes us reconsider the systematic determination of ANA after an obstetrical event because in the case where ANA are found positive, an adapted follow-up would reduce the negative impact of ANA presence on subsequent pregnancies.

Prevalence of autoimmune conditions in pregnant women in a tertiary maternity hospital: A cross-sectional survey and maternity database review

Background

Autoimmune conditions are associated with adverse pregnancy and offspring outcomes; however, the prevalence in pregnant women is not well understood. Estimates based on administrative data alone may underestimate prevalence.

Methods

A cross-sectional survey of women attending a tertiary referral hospital for antenatal care in December 2018-February 2019 and review of the hospital's maternity database of women giving birth from October 2017-June 2018 to estimate autoimmune disease prevalence.

Results

A total of 400 women completed surveys (78% response rate) and 41 (10.3%) reported an autoimmune disease, most commonly Hashimoto's thyroiditis (2.8%) and psoriasis (2.5%). From the maternity database, 112 of 2756 women giving birth (4.1%) had a recorded autoimmune disease, most commonly Hashimoto's thyroiditis (1.3%) followed by coeliac disease, Graves' disease, and immune thrombocytopenic purpura (all 0.4%).

Conclusion

Autoimmune disease prevalence in pregnant women is higher when self-reported and may be more common than previously reported using administrative data.

Identification of Two Different Phenotypes of Patients with Amiodarone-Induced Thyrotoxicosis and Positive Thyrotropin Receptor Antibody Tests

Introduction: Serum thyrotropin (TSH) receptor antibodies (TRAbs) are occasionally found in patients with amiodarone-induced thyrotoxicosis (AIT), and usually point to a diagnosis of type 1 AIT (AIT1) due to Graves' disease (GD). However, the TRAb role and function in AIT have not been clarified. Methods: A retrospective cohort study of 309 AIT patients followed at a single academic center over a 30-year period. AIT TRAb-positive patients (n = 21, 7% of all cases) constituted the study group; control groups consisted of type 2 AIT (AIT2) TRAb-negative patients (n = 233), and 100 non-AIT patients with GD. Clinical and biochemical data at diagnosis and during the course of disease were compared. Histological samples of patients who had total thyroidectomy were reviewed. Stored serum samples were used for a functional assay of TRAb class G immunoglobulins (IgGs) in Chinese hamster ovary (CHO) cells stably transfected with complementary DNA encoding for the TSH receptor. Results: TRAb-positive patients were grouped according to color flow Doppler sonography, radioactive iodine thyroid uptake, and duration of amiodarone therapy before thyrotoxicosis in type 1 (n = 9, 43%; TRAb1) or type 2 (n = 12, 57%; TRAb2) AIT. TRAb1 patients had clinical and biochemical features indistinguishable from GD controls, and were responsive to methimazole. Conversely, TRAb2 patients had clinical features similar to AIT2 controls, and were responsive to glucocorticoids, but not to methimazole. The CHO cell functional assay demonstrated that TRAb1 IgGs had a stimulatory effect on cyclic AMP production, which was absent in TRAb2 IgGs. Pathology in TRAb1 showed hyperplastic thyroid follicles and mild lymphocyte infiltration, reflecting thyroid stimulation. On the contrary, TRAb2 samples revealed follicle destruction, macrophage infiltration, and sometimes fibrosis, consistent with a destructive process. Conclusions: Almost 60% of TRAb-positive AIT patients had a destructive thyroiditis. TRAb-positive tests in AIT patients do thus not necessarily imply a diagnosis of GD and AIT1, and should be evaluated in the clinical and biochemical setting of each AIT patient and confirmed by measuring thyroid-stimulating immunoglobulins.

The Efficacy of Assisted Reproduction in Women with a Wide Spectrum of Chronic Diseases - A Review

Assisted reproductive technology (ART) treatments in women with underlying chronic diseases have become increasingly frequent. The objective of this review is to provide an overview of the literature examining the chance of having a live born child after ART in women with chronic diseases, compared to other women receiving ART. We focused on some of the most prevalent chronic diseases in women during their reproductive years, ie ulcerative colitis, Crohn’s disease, rheumatoid arthritis, multiple sclerosis, epilepsy, hyperthyroidism, hypothyroidism, and diabetes mellitus. Secondly, we studied the chance of successful implantation. The literature search was performed in the database Pubmed.gov. including all studies published before October 2020. Title and abstracts of 58 papers were reviewed, 37 papers were excluded and other 8 studies were excluded after full-text evaluation. Only 13 papers were eligible for review. Results indicate that women with ulcerative colitis, Crohn’s disease, rheumatoid arthritis, hyperthyroidism, and diabetes mellitus type 2 might have problems with low implantation rate or early embryo development during ART. On the contrary, the few studies on women with hypothyroidism, diabetes mellitus type 1, and epilepsy suggest an equivalent chance of a live birth compared to other women undergoing ART. A possible explanation behind these differences could reside in the disease-specific dysregulation of the innate or adaptive immune system. To our knowledge, this is the first review on ART in women with chronic diseases, and it has disclosed that the evidence in this area is indeed sparse. We encourage others to examine live birth after ART in women with chronic diseases.

Genetic Thyrotropin Regulation of Atrial Fibrillation Risk Is Mediated Through an Effect on Height

CONTEXT

A genetic predisposition to lower thyrotropin (TSH) levels is associated with increased atrial fibrillation (AF) risk through undefined mechanisms.

OBJECTIVE

Defining the genetic mediating mechanisms could lead to improved targeted therapies to mitigate AF risk.

METHODS

We used 2-sample mendelian randomization (MR) to test associations between TSH-associated single-nucleotide variations and 16 candidate mediators. We then performed multivariable mendelian randomization (MVMR) to test for a significant attenuation of the genetic association between TSH and AF, after adjusting for each mediator significantly associated with TSH.

RESULTS

Four candidate mediators (free thyroxine, systolic blood pressure, heart rate, and height) were significantly inversely associated with genetically predicted TSH after adjusting for multiple testing. In MVMR analyses, adjusting for height significantly decreased the magnitude of the association between TSH and AF from -0.12 (SE 0.02) occurrences of AF per SD change in height to -0.06 (0.02) (P = .005). Adjusting for the other candidate mediators did not significantly attenuate the association.

CONCLUSION

The genetic association between TSH and increased AF risk is mediated, in part, by taller stature. Thus, some genetic mechanisms underlying TSH variability may contribute to AF risk through mechanisms determining height occurring early in life that differ from those driven by thyroid hormone-level elevations in later life.

Current approaches and developments in transcript profiling of the human placenta

BACKGROUND

The placenta is the active interface between mother and foetus, bearing the molecular marks of rapid development and exposures in utero. The placenta is routinely discarded at delivery, providing a valuable resource to explore maternal-offspring health and disease in pregnancy. Genome-wide profiling of the human placental transcriptome provides an unbiased approach to study normal maternal–placental–foetal physiology and pathologies.

OBJECTIVE AND RATIONALE

To date, many studies have examined the human placental transcriptome, but often within a narrow focus. This review aims to provide a comprehensive overview of human placental transcriptome studies, encompassing those from the cellular to tissue levels and contextualize current findings from a broader perspective. We have consolidated studies into overarching themes, summarized key research findings and addressed important considerations in study design, as a means to promote wider data sharing and support larger meta-analysis of already available data and greater collaboration between researchers in order to fully capitalize on the potential of transcript profiling in future studies.

SEARCH METHODS

The PubMed database, National Center for Biotechnology Information and European Bioinformatics Institute dataset repositories were searched, to identify all relevant human studies using ‘placenta’, ‘decidua’, ‘trophoblast’, ‘transcriptome’, ‘microarray’ and ‘RNA sequencing’ as search terms until May 2019. Additional studies were found from bibliographies of identified studies.

OUTCOMES

The 179 identified studies were classifiable into four broad themes: healthy placental development, pregnancy complications, exposures during pregnancy and in vitro placental cultures. The median sample size was 13 (interquartile range 8–29). Transcriptome studies prior to 2015 were predominantly performed using microarrays, while RNA sequencing became the preferred choice in more recent studies. Development of fluidics technology, combined with RNA sequencing, has enabled transcript profiles to be generated of single cells throughout pregnancy, in contrast to previous studies relying on isolated cells. There are several key study aspects, such as sample selection criteria, sample processing and data analysis methods that may represent pitfalls and limitations, which need to be carefully considered as they influence interpretation of findings and conclusions. Furthermore, several areas of growing importance, such as maternal mental health and maternal obesity are understudied and the profiling of placentas from these conditions should be prioritized.

WIDER IMPLICATIONS

Integrative analysis of placental transcriptomics with other ‘omics’ (methylome, proteome and metabolome) and linkage with future outcomes from longitudinal studies is crucial in enhancing knowledge of healthy placental development and function, and in enabling the underlying causal mechanisms of pregnancy complications to be identified. Such understanding could help in predicting risk of future adversity and in designing interventions that can improve the health outcomes of both mothers and their offspring. Wider collaboration and sharing of placental transcriptome data, overcoming the challenges in obtaining sufficient numbers of quality samples with well-defined clinical characteristics, and dedication of resources to understudied areas of pregnancy will undoubtedly help drive the field forward.

Thyroid autoimmunity is associated with higher risk of premature ovarian insufficiency-a nationwide Health Insurance Research Database study

STUDY QUESTION

Is thyroid autoimmunity associated with a higher risk of low ovarian reserve and POI?

SUMMARY ANSWER

Thyroid autoimmunity significantly increases the risk of POI in women.

WHAT IS KNOWN ALREADY

POI is closely related with autoimmune disease, and according to some studies, thyroid autoimmunity (TAI) may account for diminished ovarian reserve. However, no large-scale cohort study has demonstrated the association between TAI and POI.

STUDY DESIGN, SIZE, DURATION

A longitudinal population-based retrospective cohort study on the National Health Insurance Research Database (NHIRD) was designed. Since 1 March 1995, the National Health Insurance (NHI) programme in Taiwan has included 99.9% of the 23 million population of Taiwan. Patients between 1 January 2000 and 31 December 2012 were eligible for recruitment, and 21 325 subjects were analysed in our study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Two cohorts, Hashimoto's and Grave's disease, were composed of patients with autoimmune thyroid disease between 20 and 40 years of age. The comparison cohorts consisted of patients in the NHIRD without autoimmune thyroid disease matched by age at a ratio of 1:4 in subject numbers.

MAIN RESULTS AND THE ROLE OF CHANCE

The Hashimoto's disease (HD) cohort, Grave's disease (GD) cohort and two comparison cohorts were followed up until a diagnosis of amenorrhoea, menopausal syndrome, other ovarian failure or infertility due to ovarian failure had been made. Compared statistically with the non-HD cohort, patients with HD exhibited an 89% higher risk of amenorrhoea (95% CI =1.36-2.61). The HD patients exhibited a 2.40-fold higher risk of infertility due to ovarian failure than the non-HD subjects (hazard ratio (HR)=2.40, 95% confidence interval (CI)=1.02-5.68). In comparison with the non-GD cohort, patients with GD exhibited a 68% higher risk of amenorrhoea (95% CI = 1.43-1.98) after adjustment. According to the Kaplan-Meier analysis, the cumulative incidence of amenorrhoea and menopausal syndrome was significantly higher in the TAI groups than in the control groups.

LIMITATIONS, REASONS FOR CAUTION

This is a retrospective study using ICD-9 disease code analysis to determine the statistical association between two diseases.

WIDER IMPLICATIONS OF THE FINDINGS

Given that autoimmune thyroid disease is highly associated with early diminished ovarian reserve or even premature ovarian failure or POI, the options for infertility treatment may be re-directed to more efficient methods in infertile patients diagnosed with the disease. If the ovarian reserve is normal at the time of diagnosis of thyroid autoimmune disease, close follow-up of ovarian reserve may be highly recommended.

STUDY FUNDING/COMPETING INTEREST(S)

This study is supported in part by Taiwan Ministry of Health and Welfare Clinical Trial Center, Grant Number: MOHW109-TDU-B-212-114004. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Changes in thyroid function during controlled ovarian hyperstimulation (COH) and its impact on assisted reproduction technology (ART) outcomes: a systematic review and meta-analysis

BACKGROUND

To investigate the thyroid function changes during controlled ovarian hyperstimulation (COH) and ascertain its impact on reproductive outcomes.

METHODS

We conducted meta-analysis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive literature search was performed to identify studies reported changes in thyroid parameters during COH. We analyzed thyroid-stimulating hormone (TSH) levels, free thyroxin (fT4) levels, changes in estrogens (E2), thyroxine-binding globulin (TBG), relative risks (RRs) of clinical pregnancy rate (CPR), live birth rate (LBR), and mean difference (MD) of TSH increment between the miscarriage group and ongoing pregnancy group.

RESULTS

This meta-analysis included fifteen individual studies (n = 1665 subjects). At the end of COH, the mean TSH (2.53 mIU/L; 95% CI, 2.19 to 2.88; I² = 92.9%) exceeded the upper limit (2.5 mIU/L) and remained above the threshold until one month following embryo transfer (ET). Thyroxin decreased from baseline to the end of COH (-0.18 ng/l; 95% CI, -0.35 to 0.00; I² = 92.2%). The CPR and LBR of patients with TSH exceeding the cutoff after COH were significantly lower than those of patients with TSH below the threshold (CPR: RR, 0.62; 95% CI, 0.47 to 0.82; I² = 0.0% and LBR: RR, 0.64; 95% CI, 0.44 to 0.92; I² = 0.0%). The MD of the increment in TSH levels between the miscarriage and ongoing pregnancy groups was 0.40 mIU/L (95% CI, 0.15 to 0.65; I² = 0.0%).

CONCLUSIONS

This meta-analysis shows that TSH increases and fT4 decreases during COH. COH-induced thyroid disorder impairs reproductive outcomes.

Subclinical thyroid diseases and isolated hypothyroxinemia during pregnancy

Thyroid diseases in pregnancy are common. While data on management of overt diseases are clear, there is no consensus regarding subclinical thyroid disease. Many studies have tried to clarify the impact of subclinical thyroid disease on pregnancy outcomes without reaching universal conclusions. As several studies are present in literature, but no univocal indication is present to manage each condition, the present review tries to summarize the recent indications for such disease. The most updated guidelines are 2017 American thyroid association for thyroid disease during pregnancy, which at present represent the most accurate and reliable guide. Subclinical hyperthyroidism during pregnancy has not been associated with adverse outcomes and only needs follow up. Subclinical hypothyroidism is associated with adverse obstetric and offspring outcomes. At present thyroxine treatment is recommended in selected cases, as beneficial effects are not clear for all these patients. Data regarding the association between isolated hypothyroxinemia and adverse maternofetal outcome are controversial but treatment is not indicated. Autoimmune thyroid disease represents the main thyroid risk factor for adverse pregnancy outcomes. If patients have normal TSH values, treatment is not indicated. A possible thyroxine treatment can be evaluated on a case-by-case basis in euthyroid patients with history of abortion/infertility. In the last years, risks of subclinical thyroid dysfunction on the outcome of gestation and new-born have been scaled back. Further prospective studies are necessary to better understand thyroid dysfunction in pregnancy to perfectly target treatment in appropriate settings.

Preconception Thyrotropin Levels and Risk of Adverse Pregnancy Outcomes in Chinese Women Aged 20 to 49 Years

IMPORTANCE

Maternal thyrotropin levels during gestation have a profound effect on pregnancy outcomes; however, few studies to date have evaluated the importance of preconception thyrotropin levels.

OBJECTIVE

To investigate the associations between preconception thyrotropin levels and pregnancy outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study enrolled Chinese women aged 20 to 49 years from the National Free Prepregnancy Checkups Project in China. Participants conceived within 6 months after the thyrotropin examination and completed follow-up for pregnancy outcomes between January 1, 2013, and December 31, 2017. Data were analyzed between May 1, 2019, and March 31, 2020.

EXPOSURES

Levels of thyrotropin within 6 months before pregnancy, measured as less than 0.10 mIU/L, 0.10 to 0.36 mIU/L, 0.37 to 2.49 mIU/L, 2.50 to 4.87 mIU/L, 4.88 to 9.99 mIU/L, and 10.00 mIU/L or greater.

MAIN OUTCOMES AND MEASURES

The association of maternal preconception thyrotropin levels with the 4 primary adverse pregnancy outcomes was assessed, including preterm birth (PTB), small for gestational age (SGA), birth defect, and perinatal infant death. Logistic regression analyses were used to evaluate the association between preconception maternal thyrotropin levels and risk of adverse pregnancy outcomes. The dose-response associations were assessed using restricted cubic spline regression.

RESULTS

This study enrolled 5 840 894 women (mean [SD] age, 26.30 [4.10] years) in the primary analysis. The median (interquartile range [IQR]) thyrotropin level was 1.60 (1.06-2.37) mIU/L. The cumulative incidences for the adverse pregnancy outcomes were as follows: PTB, 6.56%; SGA, 7.21%; birth defect, 0.02%; and perinatal infant death, 0.33%. Compared with the reference group (thyrotropin range, 0.37-2.49 mIU/L), both low (<0.10 mIU/L and 0.10-0.36 mIU/L) and high (4.88-9.99 mIU/L and ≥10.00 mIU/L) maternal preconception thyrotropin levels were associated with higher risk of PTB (low: odds ratio [OR], 1.23 [95% CI, 1.19-1.27] and OR, 1.15 [95% CI, 1.13-1.18] vs high: OR, 1.13 [95% CI, 1.10-1.15] and OR, 1.14 [95% CI, 1.08-1.20]), SGA (low: OR, 1.37 [95% CI, 1.33-1.40] and OR, 1.14 [95% CI, 1.12-1.17] vs high: OR, 1.05 [95% CI, 1.03-1.08] and OR, 1.17 [95% CI, 1.11-1.23]), and perinatal infant death (low: OR, 1.26 [95% CI, 1.10-1.43] and OR, 1.14 [95% CI, 1.05-1.24] vs high: OR, 1.31 [95% CI, 1.20-1.43] and OR, 1.47 [95% CI, 1.21-1.80]). J-shaped associations between preconception thyrotropin levels and PTB (χ2 = 1033.45; nonlinear P < .001), SGA (χ2 = 568.90; nonlinear P < .001), and perinatal infant death (χ2 = 38.91; nonlinear P < .001) were identified.

CONCLUSIONS AND RELEVANCE

In this cohort study, both low and high maternal thyrotropin levels were associated with a significantly increased risk of adverse pregnancy outcomes. Results suggest that the optimal preconception thyrotropin levels may be between 0.37 mIU/L and 2.50 mIU/L to prevent adverse pregnancy outcomes.

Variations in the Antithyroid Antibody Titre During Pregnancy and After Delivery

Background

Immunosuppression occurs during pregnancy, and the antithyroid antibody titre drops, rebounding after delivery. We aimed to determine variations in antithyroid antibody titres during pregnancy and after delivery.

Methods

This retrospective study was conducted in a single centre. Antibody titres of 142 patients were measured to assess variations in the levels of thyroid-stimulating hormone receptor antibodies (TRAbs), thyroid peroxidase antibodies (TPOAbs), and thyroid globulin antibodies (TgAbs). We compared the titres of each antibody between adjacent time periods (eg, first trimester (T1) vs second trimester (T2), T2 vs third trimester (T3), T3 vs the postpartum period (PP)) by paired t-test or the Wilcoxon test. Then, we analysed data from patients with complete laboratory examination results in all four periods with the Friedman test, performing comparisons among groups.

Results

In the TgAb group, significant differences existed between T1 and T2 and between T2 and T3 in the LT4 subgroup and between T1 and T2 in the no-medication subgroup. In the TRAb group, significant differences existed between T1 and T2 in the LT4 subgroup. In the TPOAb group, significant differences existed among each group in the LT4 subgroup, and there were significant differences between T1 and T2 and between T2 and T3 in the no-medication subgroup. The Friedman test showed that the P-values were 0.013 and 0.004 in the LT4 and no-medication subgroups of the TgAb group, respectively; 0.122 in the LT4 subgroup of the TRAb group; and <0.001 and 0.272 in the LT4 and no-medication subgroups of the TPOAb group, respectively. In the LT4 subgroup of the TgAb group, the P-values for comparisons of time periods were 0.602 between T1 and T2, 0.602 between T2 and T3, 0.006 between T1 and T3, and 0.602 between T3 and PP. In the no-medication subgroup of the TgAb group, the P-values were 0.078 between T1 and T2, 1.000 between T2 and T3, 0.011 between T1 and T3, and 0.078 between T3 and PP. In the LT4 subgroup of the TPOAb group, the P-values were 0.09 between T1 and T2, 0.014 between T2 and T3, <0.001 between T1 and T3, and 0.772 between T3 and PP.

Conclusion

We can conclude that the TgAb and TPOAb titres dropped during pregnancy.

A Novel Nomogram for Predicting the Risk of Premature Delivery Based on the Thyroid Function in Pregnant Women

BACKGROUND

Maternal thyroid dysfunction and autoantibodies were associated with preterm delivery. However, recommendations for cutoff values of thyroperoxidase antibody (TPOAb) positivity and thyroid-stimulating homone (TSH) associated with premature delivery are lacking.

OBJECTIVE

To identify the pregnancy-specific cutoff values for TPOAb positivity and TSH associated with preterm delivery. To develop a nomogram for the risk prediction of premature delivery based on maternal thyroid function in singleton pregnant women without pre-pregnancy complications.

METHODS

This study included data from the International Peace Maternity and Child Care Health Hospital (IPMCH) in Shanghai, China, between January 2013 and December 2016. Added data between September 2019 and November 2019 as the test cohort. Youden's index calculated the pregnancy-specific cutoff values for TPOAb positivity and TSH concentration. Univariate and multivariable logistic regression analysis were used to screen the risk factors of premature delivery. The nomogram was developed according to the regression coefficient of relevant variables. Discrimination and calibration of the model were assessed using the C-index, Hosmer-Lemeshow test, calibration curve and decision curve analysis.

RESULTS

45,467 pregnant women were divided into the training and validation cohorts according to the ratio of 7: 3. The testing cohort included 727 participants. The pregnancy-specific cutoff values associated with the risk of premature delivery during the first trimester were 5.14 IU/mL for TPOAb positivity and 1.33 mU/L for TSH concentration. Multivariable logistic regression analysis showed that maternal age, history of premature delivery, elevated TSH concentration and TPOAb positivity in the early pregnancy, preeclampsia and gestational diabetes mellitus were risk factors of premature delivery. The C-index was 0.62 of the nomogram. Hosmer-Lemeshow test showed that the Chi-square value was 2.64 (P = 0.955 > 0.05). Decision curve analysis showed a positive net benefit. The calibration curves of three cohorts were shown to be in good agreement.

CONCLUSIONS

We identified the pregnancy-specific cutoff values for TPOAb positivity and TSH concentration associated with preterm delivery in singleton pregnant women without pre-pregnancy complications. We developed a nomogram to predict the occurrence of premature delivery based on thyroid function and other risk factors as a clinical decision-making tool.

Pregnancy outcomes in women with preexisting thyroid diseases: a French cohort study

Women with thyroid diseases at the beginning of pregnancy may have suboptimal thyroid hormone levels because of potential difficulties in compensating for the physiological thyroid hormone changes occurring in pregnancy. Our objective was to study the association between preexisting thyroid diseases, pregnancy complications, and neonatal anthropometry. In total, 16,395 women from the ELFE French longitudinal birth cohort were included, and 273 declared pre-pregnancy thyroid diseases. Associations were investigated with multivariable regression models, with adjustment for relevant potential confounders. Body mass index (BMI) was additionally adjusted for in a second stage. As compared with other women, women with pre-pregnancy thyroid diseases were more frequently obese (19.6% vs. 9.8%) and had greater odds of gestational diabetes development (odds ratio [OR] = 1.58 [95% confidence interval [CI] 1.08, 2.30]) or had undergone treatment for infertility (OR = 1.57 [95% CI 1.07, 2.31]). After adjustment for BMI, the association with gestational diabetes was no longer significant (OR = 1.27 [95% CI 0.86, 1.88]). After excluding women with another medical history, those with pre-pregnancy thyroid diseases had increased odds of premature rupture of membranes (OR = 1.51 [95% CI 1.01, 2.25]). Children born from mothers with hypothyroidism before conception due to a disease or as a potential side effect of treatment had a smaller head circumference at birth than other children (β = -0.23 [95% CI -0.44, -0.01] cm). In conclusion, pre-pregnancy thyroid diseases were associated with risk of infertility treatment, gestational diabetes, and premature rupture of membranes. The association between history of hypothyroidism and moderate adverse effects on fetal head circumference growth needs replication.

The Clinical Value and Variation of Antithyroid Antibodies during Pregnancy

Antithyroid antibodies, which include thyroid-stimulating hormone receptor antibodies (TRAbs), thyroid peroxidase antibodies (TPOAbs), and thyroid globulin antibodies (TgAbs), are widely known for their tight association with thyroid autoimmune diseases. The variation in all three kinds of antibodies also showed different trends during and after pregnancy (Weetman, 2010). This article reviewed the the physiological changes, while focusing on the variation of thyroid antibodies concentration in women during and after pregnancy, and adverse consequences related to their elevation. Since abnormal elevations of these antithyroid antibodies may lead to adverse outcomes in both mothers and fetuses, special attention must be paid to the titer of the antibodies during pregnancy. The molecular mechanisms of the variations in those antibodies have yet to be explained. The frequency and timing of thyroid antibody measurement, as well as different reference levels, also remain to be elucidated.

Thyroid disorders in subfertility and early pregnancy

Disorders of thyroid function are common in pregnancy and have implications for foetal and maternal health. Thyroid autoimmunity, as evidenced by the presence of elevated levels of anti-thyroid antibodies (anti-TPO and anti-Tg antibodies) is associated with an increased risk of miscarriage, though the mechanism remains poorly understood. There has been considerable focus on the implications and optimal management of pregnant women with thyroid disease, especially those undergoing assisted reproduction. Pregnancy results in significant changes in thyroid physiology and these need to be understood by clinicians involved in the care of pregnant women. Guidelines for the use of thyroxine and target thyroid function tests have been produced by international bodies but it is recognised that these predominantly reflect expert opinion rather than established evidence-based practice. Importantly a number of key clinical trials have been performed to aid understanding, particularly of the consequences of hypothyroidism for mother and baby, and the effectiveness of thyroid hormone use in autoimmune and subclinical hypothyroidism. This review summarises the current knowledge base and guidance for practice relating to thyroid disorders in pregnancy and subfertility.

Early pregnancy reference intervals; 29 serum analytes from 4 to 12 weeks' gestation in naturally conceived and uncomplicated pregnancies resulting in live births

Background Pregnancy introduces major physiological changes that also alter biochemical analytes. Maternal and perinatal health can be optimized by early intervention and therefore, pregnancy-specific reference intervals (RIs) for the local population are warranted. While the second and third trimester-specific changes are well described, the first trimester is less well characterized. We therefore wanted to facilitate early detection of abnormalities by generating first trimester reference values for 29 common analytes. Methods In a prospective early pregnancy (PEP) cohort (2016-2017), 203 pregnant women were recruited from 4 to 8 weeks' gestation. Consecutive blood samples were drawn every 2 weeks until an ongoing second trimester pregnancy (n = 164) or a miscarriage (n = 39) occurred. After exclusion of women with complicated pregnancies or deliveries (n = 42), 122 women were included. The serum samples collected at <6, 6-8, 8-10, 10-12 and >12 weeks' gestation were analyzed for 29 common analytes. Subsequently the RIs were calculated according to the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommendations (2.5-97.5th percentiles) and compared with the conventional RIs for non-pregnant women. Results Human chorionic gonadotropin (hCG), progesterone (P4), estradiol (E2), pregnancy-associated plasma protein A (PAPP-A), cancer antigen 125 (CA125), thyroid stimulating hormone (TSH), creatinine (CREA) and albumin (ALB) showed an early pregnancy-dependent change compared with conventional limits. For ALB the change was seen at 5.5 weeks' gestation. Conclusions We report gestational age-specific RIs available from the early part of the first trimester applicable to everyday clinical care of pregnant women. Well-known alterations of RIs seen in later trimesters are also observed in the first.

Immunoglobulin Preparations Can Mislead Clinical Decision-Making in Follow-Up of Differentiated Thyroid Cancer

OBJECTIVE

Intravenous and subcutaneous immunoglobulins are commonly used for immune substitution or as immune modulators in a variety of inflammatory and autoimmune disorders. Exogenous thyroid-specific thyroglobulin (Tg) antibodies present in the donor plasma may interfere with the interpretation of measurements of Tg autoantibodies (Tg-Abs) in the recipient's plasma and potentially trigger an immune response in the recipient's immune cells. Levels of antibodies causing bioassay interferences or those leading to clinically relevant changes in patient outcomes are not known. Tg is used as a biomarker in the long-term surveillance of patients with differentiated thyroid cancer (DTC) following total thyroidectomy and radioactive iodine ablation. However, the presence of Tg-Abs in the circulation interferes with Tg measurements. Assessment of levels of Tg-Abs is thus recommended as a part of standard follow-up of DTC together with Tg testing.

METHODS

To understand the potential mechanisms and pathophysiologic significance of possible interferences associated with administration immunoglobulin preparations and Tg measurement, we overview the current knowledge on interactions between Tg autoimmunity and immunoglobulin preparations and illustrate diagnostic challenges and perspectives for follow-up of patients with DTC treated with exogenous immunoglobulins.

RESULTS

In patients with DTC treated with immunoglobulin preparations, monitoring of thyroid cancer using Tg and Tg-Abs is challenging due to possible analytical interferences through passive transfer of exogenous antibodies from immunoglobulin preparations.

CONCLUSION

Analytical interferences must be suspected when a discrepancy exists between clinical examination and diagnostic tests. Collaboration between endocrinologists, biologists, and pharmacologists is fundamental to avoid misdiagnosis and unnecessary medical or radiologic procedures.

ABBREVIATIONS

CT = computed tomography; DTC = differentiated thyroid cancer; FNAB = fine-needle aspiration biopsy; HAb = heterophile antibody; IMA = immunometric assay; IVIg = intravenous immunoglobulin; RAI = radioactive iodine; RIA = radioimmunoassay; SCIg = subcutaneous immunoglobulin; Tg = thyroglobulin; Tg-Ab = thyroglobulin autoantibody; Tg-MS = thyroglobulin mass spectrometry; TPO-Ab = thyroid peroxidase autoantibody; TSHR-Ab = thyrotropin receptor autoantibody.

Universal screening for thyroid disease during pregnancy should be performed

Thyroid disease can significantly impact the pregnant woman and her child. Human and animal studies have firmly linked overt hypothyroidism and overt hyperthyroidism to miscarriage, preterm delivery and other adverse pregnancy outcomes. Overt hypothyroidism and overt hyperthyroidism affect 1% of all pregnancies. Treatment is widely available, and if detected early, results in decreased rates of adverse outcomes. Universal screening for thyroid disease in pregnancy can identify patients with thyroid disease requiring treatment, and ultimately decrease rates of complications. Universal screening is cost-effective compared to the currently accepted practice of targeted screening and may even be cost-saving in some healthcare systems. Targeted screening, which is recommended by most professional associations, fails to detect a large proportion of pregnant women with thyroid disease. In fact, an increasing number of providers are performing universal screening for thyroid disease in pregnancy, contrary to society guidelines. Limited evidence concerning the impact of untreated and treated subclinical disease and thyroid autoimmunity has distracted from the core rationale for universal screening - the beneficial impact of detecting and treating overt thyroid disease. Evidence supporting universal screening for overt disease stands independently from that of subclinical and autoimmune disease. The time to initiate universal screening is now.

Universal screening for thyroid disease SHOULD NOT be recommended before and during pregnancy

Thyroid dysfunction in pregnancy is strongly associated with adverse maternal and foetal outcomes. The effects of treatment are less clear. There is ongoing discussion on whom to treat, when to treat and whether treatment is beneficial. Although universal screening for thyroid disease during pregnancy increases diagnosis and treatment of thyroid dysfunction, there is currently insufficient evidence demonstrating a positive effect of screening on maternal and foetal outcomes. We therefore, at present, recommend against universal screening for thyroid disease before and during pregnancy.

Effect of levothyroxine supplementation on pregnancy loss and preterm birth in women with subclinical hypothyroidism and thyroid autoimmunity: a systematic review and meta-analysis

BACKGROUND

Subclinical hypothyroidism (SCH) and thyroid autoimmunity (TAI) are associated with adverse pregnancy outcomes such as pregnancy loss and preterm birth. However, the ability of levothyroxine (LT4) supplementation to attenuate the risks of these outcomes remains controversial.

OBJECTIVE AND RATIONALE

This systematic review and meta-analysis was conducted to determine the effect of LT4 supplementation on pregnancy loss rate (PLR) and preterm birth rate (PBR) among pregnant women with SCH and TAI.

SEARCH METHODS

A systematic literature search of the PubMed, EMBASE, Web of Science and Cochrane Controlled Trials Register databases and Clinicaltrials.gov was performed to identify all relevant English studies published up to April 2018. The following terms were used for the search: [subclinical hypothyroidism OR thyroid autoimmunity OR thyroperoxidase antibody (TPO-Ab) OR thyroglobulin antibodies (Tg-Ab)] AND (levothyroxine OR euthyrox) AND [pregnancy outcome OR miscarriage OR abortion OR pregnancy loss OR preterm birth OR premature delivery OR early labo(u)r]. The reference lists of the relevant publications were also manually searched for related studies. Published manuscripts were included if they reported data on pregnancy loss, preterm birth or both. We separately analysed the pooled effects of LT4 supplementation on PLR and PBR in women with SCH and TAI.

OUTCOMES

Overall, 13 eligible studies including 7970 women were included in the meta-analysis. Eight and five of these studies were randomized controlled trials (RCTs) and retrospective studies, respectively. The pooled results indicated that LT4 supplementation significantly decreased the PLR [relative risk (RR) = 0.56, 95% confidence interval (CI): 0.42-0.75, I2 = 1%, 12 studies] and PBR (RR = 0.68, 95% CI: 0.51-0.91, I2 = 21%, eight studies) in women with SCH and/or TAI. We further found that LT4 supplementation significantly decreased the risk of pregnancy loss (RR = 0.43, 95% CI: 0.26-0.72, P = 0.001, I2 = 0%) but not of preterm birth (RR = 0.67, 95% CI: 0.41-1.12, P = 0.13, I2 = 0%) in women with SCH. Furthermore, LT4 supplementation significantly decreased the risks of both pregnancy loss (RR = 0.63, 95% CI: 0.45-0.89, P = 0.009, I2 = 0%) and preterm birth (RR = 0.68 95% CI: 0.48-0.98, P = 0.04, I2 = 46%) in women with TAI. These results were consistent when only RCTs were included in the analysis. Further, in women with SCH, LT4 supplementation reduced the risk of pregnancy loss in pregnancies achieved by assisted reproduction (RR = 0.27, 95% CI: 0.14-0.52, P < 0.001, I2 = 14%) but not in naturally conceived pregnancies (RR = 0.60, 95% CI: 0.28-1.30, P = 0.13, I2 = 0%). By contrast, in women with TAI, LT4 supplementation reduced the risks of both pregnancy loss (RR = 0.61, 95% CI: 0.39-0.96, P = 0.03, I2 = 0%) and preterm birth (RR = 0.49, 95% CI: 0.30-0.79, P = 0.003, I2 = 0%) in naturally conceived pregnancies but not in pregnancies achieved by assisted reproduction (RR = 0.68, 95% CI: 0.40-1.15, P = 0.15, I2 = 0% for pregnancy loss and RR = 1.20, 95% CI: 0.68-2.13, P = 0.53, I2 not applicable for preterm birth).

WIDER IMPLICATIONS

This meta-analysis confirmed the beneficial effects of LT4 supplementation, namely the reduced risks of pregnancy loss and preterm birth, among pregnant women with SCH and/or TAI. The different effects of LT4 supplementation on naturally conceived pregnancies and pregnancies achieved by assisted reproduction in women with SCH and/or TAI suggest that these women should be managed separately. Due to the limited number of studies included in this meta-analysis, especially in the subgroup analysis, further large RCTs and fundamental studies are warranted to confirm the conclusions and better clarify the molecular mechanism underlying these associations.

A Meta-Analysis of Pregnancy Outcomes With Levothyroxine Treatment in Euthyroid Women With Thyroid Autoimmunity

CONTEXT

Thyroid autoimmunity (TAI), the most common cause of (sub)clinical hypothyroidism, is associated with adverse pregnancy outcomes. The benefits of levothyroxine (LT4) intervention in women with TAI remain controversial.

OBJECTIVE

The purpose of this analysis is to determine the effect of LT4 on pregnancy outcomes in euthyroid women with TAI.

DATA SOURCES

Databases were searched up to May 2019.

STUDY SELECTION

Randomized controlled trails (RCTs) and retrospective studies that reported effects of LT4 administration on pregnancy outcomes in euthyroid women with TAI were screened.

DATA EXTRACTION

Quality assessment and data extraction were conducted independently by 2 researchers. Conflicts were settled by a third researcher.

DATA SYNTHESIS

Six trials comprising 2249 women were included. Overall, no beneficial effect on pregnancy outcomes was observed with LT4 supplementation. For women with individualized initial LT4 dosages, the risk of miscarriage decreased (relative risk [RR] 0.62, 95% CI: 0.41-0.93, I2 = 28%); there was no difference among women with fixed LT4 dosages (RR 0.96, 95% CI: 0.74-1.24, I2 = 0%). Women who initiated LT4 treatment in early pregnancy had a significantly lower preterm birth rate (RR 0.54, 95% CI: 0.31-0.92, I2 = 0%) than those who received no treatment or placebo. No improvement was observed among women who initiated treatment before conception (RR 1.14, 95% CI: 0.71-1.84, I2 = 0%).

CONCLUSION

No definitive evidence showed improvement of pregnancy outcomes with LT4 supplementation in euthyroid women with TAI. However, therapeutic strategies, especially dosages and initial times of intervention, may be of great importance. Additional large RCTs are needed in the future.

Impact of Thyroid Autoimmunity on Ovarian Reserve, Pregnancy Outcomes, and Offspring Health in Euthyroid Women Following In Vitro Fertilization/Intracytoplasmic Sperm Injection

Background: Thyroid autoimmunity (TAI) is the most frequent autoimmune disease among reproductive-aged women. It has been related to premature ovarian insufficiency, but the mechanisms remain elusive, and its association with ovarian reserve in euthyroid women is debatable. Moreover, the impact of TAI on assisted reproduction is controversial: especially for women with diminished ovarian reserve (DOR), few studies are available. Therefore, the present study was aimed to look for an association between TAI and DOR, and to evaluate the effect of TAI on pregnancy outcomes and offspring health following assisted reproductive technology stratified by ovarian reserve. Methods: A total of 6213 euthyroid women from the Reproductive Hospital Affiliated to Shandong University between 2012 and 2017 were retrospectively included. The prevalence of DOR in women with negative or positive TAI was calculated, and pregnancy and neonatal outcomes after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles were compared between the TAI-positive and TAI-negative groups both in women with DOR and in those with normal ovarian reserve (NOR). Longitudinal growth parameters and temperament type of the offspring were also observed in the TAI-positive and TAI-negative groups. Results: The prevalence of DOR in women with positive TAI and those with negative TAI was not significantly different (4.09% vs. 2.96%, p = 0.053), even after stratifying patients by age. In women with DOR, the live birth rate, pregnancy loss rate, neonatal complication rate, and offspring outcomes between the TAI-positive and TAI-negative groups were comparable (p > 0.05). In women with NOR, a higher rate of live births (44.94% vs. 40.34%, p = 0.027) and a higher prevalence of congenital anomalies (4.68% vs. 2.14%, p = 0.005) were observed in the TAI-positive group. Conclusions: TAI had no impact on ovarian reserve in euthyroid women and had no association with IVF/ICSI outcomes in women with DOR. Although an increased incidence of congenital anomalies in the TAI-positive group was observed in women with NOR, an association between neonatal anomalies and TAI cannot be demonstrated. Large cohort studies to evaluate the effects of TAI on offspring health are warranted, and further experimental studies are required to explore the underlying mechanisms.

Recurrent Pregnancy Loss in Women with Hashimoto's Thyroiditis with Concurrent Non-Endocrine Autoimmune Disorders

Background: An increased rate of recurrent miscarriage has been described in patients with autoimmune thyroid disease. However, there is a lack of studies that assess the rate of recurrent pregnancy loss (RPL) in patients with Hashimoto's thyroiditis (HT) isolated or with concurrent non-endocrine autoimmune disorders (NEAD). The objective of the study was to assess the rate of RPL in patients with HT isolated or accompanied with non-endocrine autoimmune diseases. Methods: This is a retrospective observational cohort study with a systematic review of the NEAD with concurrent HT in an outpatient Endocrinology Unit at a University Hospital. Among the 3480 consecutively examined women with HT, 87 patients met the criteria of RPL and represented the study group. Sixty-five of them had isolated HT and 22 women had HT+NEAD. Results: The rate of RPL in women with HT was 2.1% versus 5.64% observed in women with HT+NEAD (odds ratio = 2.78 [95% confidence interval 1.70-4.57]; p < 0.0001). On subdivision, this difference was still evident in euthyroid patients (p < 0.0001), while it disappeared in hypothyroid women (p = 0.21). The RPL did not correlate with the autoantibody concentrations nor in women with isolated HT nor in those with HT+NEAD. The presence of antiphospholipid syndrome (APS) explained RPL in 3 out of 22 (14%) patients with HT+NEAD, the remaining being related to different autoimmune disorders. Interestingly, even subtracting the patients with APS, RPL was more frequent in patients with poly-autoimmunity than in patients with isolated HT (p = 0.0013). Conclusions: The co-presence of NEAD is correlated with a higher risk of RPL in women with HT. The association with APS may explain only a fraction of RPL rate in patients with poly-autoimmunity.

Thyroid function of twin-pregnant women in early pregnancy

Background:

Serum human chorionic gonadotrophin (hCG) is higher in twin than that in singleton pregnancies. As hCG stimulates the thyroid to produce more free thyroxine (FT4), which may lead to decreased thyroid-stimulating hormone (TSH) levels, the reference ranges of thyroid-related indicators may differ between singleton and twin pregnancies in the first trimester. This study aimed to establish reference ranges for thyroid-related indicators in early twin pregnancies and to compare them with singleton pregnancies.

Methods:

Data of 820 twin-pregnant women were extracted from the established database of all pregnant women who delivered at Peking University First Hospital from October 2013 to May 2018; 160 who met National Academy of Clinical Biochemistry criteria were included to establish TSH and FT4 reference ranges. We screened 480 (3:1 paired) women with singleton pregnancies from the same database as controls. The Mann-Whitney test for TSH and FT4 levels was applied for comparisons between singleton and twin pregnancies.

Results:

First-trimester reference ranges (4–12 gestational weeks) for twin pregnancies were: TSH 0.69 (0.01–3.35) mIU/L and FT4 16.38 (12.45–23.34) pmol/L. Median TSH was significantly lower at 7 to 12 gestational weeks than that at 4 to 6 gestational weeks (0.62 vs. 0.96 mIU/L, Z = −1.964, P = 0.049); FT4 was not significantly different between the two groups. Compared to singleton pregnancies, median TSH was significantly lower (0.69 vs. 1.27 mIU/L, Z = −6.538, P = 0.000), and FT4 was significantly higher (16.38 vs. 14.85 pmol/L, Z = −7.399, P = 0.000) in twin pregnancies in the first trimester.

Conclusions:

Specific reference ranges for thyroid-related indicators for twin pregnancies are needed to avoid a misdiagnosis of thyroid dysfunction. Moreover, establishment of separate reference ranges for 4 to 6 and 7 to 12 gestational weeks in twin pregnancies may be considered.

Population-based estimates of humoral autoimmunity from the U.S. National Health and Nutrition Examination Surveys, 1960-2014

Objective

Based on US National Health and Nutrition Examination Survey (NHANES) data, we attempted to provide an unbiased, population-based estimate of autoantibody prevalence overall and by age and sex.

Methods

US autoantibody prevalence estimates for detectable rheumatoid factor, anti-thyroglobulin, anti-thyroperoxidase, anti-transglutaminase, anti-endomysial, anti-GAD65, antinuclear autoantibodies, and autoantibodies to extractable nuclear antigens were estimated from the 1960–1962 National Health Examination Survey, NHANES III (1988–1994), and the NHANES 1999–2014 cross-sectional surveys. Survey design variables and sample weights were used to account for differential probabilities of selection within the complex survey design. Data analysis used SAS^TM and SUDAAN^™ software. US Census Bureau data were used to estimate the absolute numbers of persons with autoantibodies.

Results

NHANES III data show that the overall US prevalence of having a detectable serum autoantibody is substantial in adults, in both women and men. Thyroid autoantibodies were present in 18% of US adults (31 million persons) including 10% of younger adults and 25% of older persons. Overall autoantibody prevalences increased significantly with age: 32% of US adults 60+ years of age (12.8 million persons) had at least one of the four autoantibodies rheumatoid factor, anti-thyroglobulin, anti-thyroperoxidase, or anti-tissue transglutaminase. Older women had higher levels of autoantibodies, but this was a relative difference. Autoantibody prevalence in both sexes was substantial (women 39%; men 22%). Fourteen percent of adults 60+ years of age have multiple autoantibodies.

Conclusions

Autoantibodies are present in a significant fraction of the general population, especially in older adults and women relative to men. Although all known clinically significant autoantibodies were not analyzed, these data provide an important population perspective on the scope and magnitude of humoral autoimmunity in the US. This is vital for prevention efforts to reduce autoimmune disease and helps clarify the potential impact of autoimmunity on the general population.

The exploration of Hashimoto's Thyroiditis related miscarriage for better treatment modalities

Hashimoto's thyroiditis (HT) is the most prevalent autoimmune thyroid disease (ATD) worldwide and is strongly associated with miscarriage and even recurrent miscarriage (RM). Moreover, with a deepening understanding, emerging evidence has shown that immune dysfunctions caused by HT conditions, including imbalanced subsets of CD4+ T-helper cells, B regulatory (Breg) cells, high expression levels of CD56dim natural killer (NK) cells, and cytokines, possibly play an important role in impairing maternal tolerance to the fetus. In recent years, unprecedented progress has been made in recognizing the specific changes in immune cells and molecules in patients with HT, which will be helpful in exploring the mechanism of HT-related miscarriage. Based on these findings, research investigating some potentially more effective treatments, such as selenium (Se), vitamin D3, and intravenous immunoglobulin (IVIG), has been well developed over the past few years. In this review, we highlight some of the latest advances in the possible immunological pathogenesis of HT-related miscarriage and focus on the efficacies of treatments that have been widely introduced to clinical trials or practice described in the most recent literature.

The pathogenic role of autoantibodies in recurrent pregnancy loss

In the present manuscript, we review the recent research investigating the pathogenic association between most studied autoantibodies and recurrent pregnancy loss. Pregnancy loss represents a common obstetric complication occurring in about 15%-25% of all clinically recognized pregnancies. The recurrence of pregnancy loss identifies a distinct clinical entity, that is recurrent pregnancy loss (RPL), affecting about 2%-4% of couples. Several factors, including age, chromosomal abnormalities, uterine anomalies, thrombophilic disorders, endocrinopathies, hormonal and metabolic disorders, infections, sperm quality, and lifestyle issues, are involved in RPL. The role of autoantibodies in RPL is only partially determined. In some cases (antiphospholipid antibodies [aPL]), their involvement is well established. In other cases (anti-thyroid autoantibodies, antinuclear, anti-transglutaminase, and anti-endomysial antibodies), it is still debated, despite multiple, although not fully conclusive, evidences strongly suggest a possible involvement in RPL. Further extensive research is needed to definitively confirm or exclude their actual role.

Subclinical hypothyroidism in pregnancy

PURPOSE OF REVIEW

Subclinical hypothyroidism (SCH) is a common diagnosis among women of reproductive age. The importance of sufficient maternal thyroid supply during pregnancy is well known. Nevertheless, the effects of SCH during pregnancy and the efficacy of its treatment on maternofetal outcomes are not well established. This review discusses the recent evidence on SCH in pregnancy and how this evidence is reflected in current clinical care.

RECENT FINDINGS

Recent observational studies have found a positive association between SCH during pregnancy and adverse maternal, neonatal and offspring outcomes, mainly in thyroid peroxidase autoantibody positive women. Although interventional studies have shown a benefit of levothyroxine (LT4) treatment on selected pregnancy outcomes, there was no effect on offspring neurodevelopment.

SUMMARY

Current evidence strengthens the association between SCH with both maternofetal and offspring adverse outcomes. An earlier and more individualized diagnostic assessment taking into consideration predictors of thyroid dysfunction and major risk factors for complications could result in better management of SCH during pregnancy. The effectiveness of LT4 on improving maternofetal and long-term offspring outcomes is still not fully elucidated.

[Thyroid and pregnancy]

During pregnancy thyroid hormones have profound effects on embryonal/fetal development and maternal health. Therefore, thyroid gland disorders should be immediately diagnosed and adequately treated. Pregnancy-specific physiological alterations during pregnancy cause changes in the reference interval for thyroid-stimulating hormone levels and trimester-specific thresholds must be taken into account. This article summarizes the most important diagnostic and therapeutic aspects before, during and after pregnancy. With reference to the period prior to pregnancy, the article discusses iodide supplementation, preconceptional examination of thyroid gland metabolism and the importance of thyroid gland functional disorders for fertility and fulfilling the desire to have children. With a view to the period during pregnancy, the effect of hypothyroxinemia, hypothyroidism, and hyperthyroidism as well as the effects of their treatment on the development of the child are explained. Finally, a description is given of what must be paid attention to in the breast-feeding period and in postpartum thyroiditis.

Autoimmune vertigo: an update on vestibular disorders associated with autoimmune mechanisms

The role of the immune system in mediating cochleovestibular pathologies has received increasing attention in recent years. Autoimmune vertigo may be an invalidating condition and may worsen the quality of life of affected patients, especially in the cases of delayed diagnosis. Since the etiopathogenesis is still not clear, also the treatment is not yet completely delineated. According to the clinical presentation, autoimmune vertigo can present as an isolated disorder or in association with systemic autoimmune diseases. The main feature in autoimmune vertigo is the presence of an abnormal immune response, in either absence or presence of systemic autoimmune disease, directed against delicate components of the inner ear. This may determine a functional or anatomical alteration, with an inflammatory reaction often devastating for hearing and balance. Being the exact pathogenesis unknown, the diagnosis of autoimmune vertigo is based either on clinical criteria or on a positive response to steroids. The earlier the diagnosis is made, the sooner the therapy can be installed, giving a chance to the recovery of inner ear damages. Corticosteroids represent the most effective and universally accepted treatment, even if other immunomodulatory drugs are now having a more extensive use. HIGHLIGHTS: Vertigo is relatively frequent in autoimmune diseases; however, it is often misdiagnosed or attributed to central nervous system alterations rather to specific inner ear involvement. Vertigo and other audiovestibular symptoms may be the first manifestation of an autoimmune disease and if correctly addressed could significantly contribute to early diagnosis of the underlying autoimmune disease. Early diagnosis of immune-related vertigo can lead to prompt initiation of targeted therapy with elevate chances of preventing irreversible damages to the inner ear. The presence of alternating phases of well-being and disabling symptoms in patients with vertigo should always been considered, as they could suggest an underlying autoimmune condition.

The chance of a live birth after assisted reproduction in women with thyroid disorders

Purpose

Women with thyroid disorders may have increased infertility and poor reproductive outcomes, but it is unclear if assisted reproductive technology (ART) is effective in this population. The aim of this study was to examine the chance of a pregnancy (biochemical and clinical), and a live birth after ART, in women with thyroid disorders undergoing ART treatment, compared to women without thyroid disorders. Among live-born children, we assessed the risk of congenital malformations.

Patients and methods

In a nationwide cohort study of all women undergoing ART treatments in Denmark from 1 January 1994 throughout June 2017, we calculated the chance of a pregnancy and a live birth after embryo transfer. Women with thyroid disorders were stratified into two groups: those diagnosed with hypothyroid or hyperthyroid disorders. The adjusted OR (aOR) of a biochemical and a clinical pregnancy, a live born child and a congenital malformation was computed using multilevel logistic regression models.

Results

In total, 199,674 embryo transfers were included in 2,101 women with thyroid disorders and in 65,526 women without thyroid disorders. The chance of a biochemical pregnancy was significantly reduced in women with hyperthyroidism (aOR=0.80, 95% CI 0.69–0.93), and the aOR of a live birth was 0.86, 95% CI 0.76–0.98. The aOR for a live birth in women with hypothyroidism was 1.03 (95% CI 0.94–1.12). Children of women with hypothyroidism, who were conceived after ART treatment, had a significantly increased risk of any congenital malformation (aOR=1.46 [95% CI 1.07–2.00]).

Conclusion

Women with hyperthyroidism receiving ART treatment had a decreased chance of a live birth per embryo transfer compared to women without thyroid disorders. Women with hypothyroidism did not have a decreased chance of a live birth but their offspring had an increased risk of congenital malformation.

The MAGI2 gene polymorphism rs2160322 is associated with Graves' disease but not with Hashimoto's thyroiditis

PURPOSE

Autoimmune thyroid diseases (AITDs) are chronic organ-specific autoimmune disorders, predominantly including Graves' disease (GD), and Hashimoto's thyroiditis (HT). This study aimed to investigate whether single-nucleotide polymorphisms (SNPs) in MAGI2 and MAGI3 gene contributed to the etiology of AITDs.

METHODS

We conducted a case-control study including 1001 patients with AITDs (625 GD, 376 HT) and 846 healthy controls. Subgroup analyses in GD and HT were also performed.

RESULTS

The genotypes of rs2160322 in MAGI2 showed a borderline association with AITDs (P = 0.048), and they had a strong correlation with GD (P = 0.012). The frequency of the minor allele G of rs2160322 was significantly higher in the GD patients than in the controls (P = 0.027; OR 1.91; 95% CI 1.020-1.391), especially for GD females (P = 0.008; OR 1.304; 95% CI 1.072-1.587), and those who had positive family history (P = 0.011; OR 1.412; 95% CI 1.083-1.843). For genetic model analysis, the recessive model and homozygous model of rs2160322 showed significant associations with AITDs (P = 0.009; P = 0.019) and GD (P = 0.004; P = 0.005). Nevertheless, our study could not identify any relationship between these SNPs and HT. Due to the low mutation rate of rs1343126 in MAGI3, we were unable to obtain a credible conclusion on its association with AITDs.

CONCLUSIONS

Our study identified that MAGI2 rs2160322 was strongly associated with GD susceptibility. The potential dysfunction of tight junction proteins and aberrant epithelial barrier caused by abnormal MAGI2 expression may be a novel mechanism of GD.

Excess iodine intake: sources, assessment, and effects on thyroid function

Iodine is essential for thyroid hormone synthesis. High iodine intakes are well tolerated by most healthy individuals, but in some people, excess iodine intakes may precipitate hyperthyroidism, hypothyroidism, goiter, and/or thyroid autoimmunity. Individuals with preexisting thyroid disease or those previously exposed to iodine deficiency may be more susceptible to thyroid disorders due to an increase in iodine intake, in some cases at intakes only slightly above physiological needs. Thyroid dysfunction due to excess iodine intake is usually mild and transient, but iodine-induced hyperthyroidism can be life-threatening in some individuals. At the population level, excess iodine intakes may arise from consumption of overiodized salt, drinking water, animal milk rich in iodine, certain seaweeds, iodine-containing dietary supplements, and from a combination of these sources. The median urinary iodine concentration (UIC) of a population reflects the total iodine intake from all sources and can accurately identify populations with excessive iodine intakes. Our review describes the association between excess iodine intake and thyroid function. We outline potential sources of excess iodine intake and the physiological responses and consequences of excess iodine intakes. We provide guidance on choice of biomarkers to assess iodine intake, with an emphasis on the UIC and thyroglobulin.

MANAGEMENT OF THYROTOXICOSIS: PRECONCEPTION, PREGNANCY, AND THE POSTPARTUM PERIOD

OBJECTIVE

To review the diagnosis and management of thyrotoxicosis in women who are preconception, pregnant, and in the postpartum period.

METHODS

Literature review of English-language papers published between 1980 and 2018.

RESULTS

Overt thyrotoxicosis occurs in 0.2% of pregnancies and subclinical thyrotoxicosis in 2.5%. Hyperthyroidism in women of childbearing age most frequently is caused by Graves disease (GD). Gestational thyrotoxicosis, transient human chorionic gonadotropin (hCG)-mediated hyperthyroidism, may develop in the first trimester. In the first year following delivery, postpartum thyroiditis, which frequently includes a thyrotoxic phase, occurs in 5% of women. Hyperthyroidism from nodular autonomy is uncommon in women of childbearing age. It is essential to understand the underlying etiology for thyrotoxicosis in order to recommend appropriate treatment. Gestational thyrotoxicosis requires supportive care, without antithyroid drug therapy. GD may be treated with antithyroid drugs, radioactive iodine, or thyroidectomy. Pregnancy, plans for pregnancy, and lactation have important implications for the choice of GD treatment. When thyrotoxicosis presents following delivery, postpartum thyroiditis must be differentiated from GD.

CONCLUSION

The diagnosis and management of thyrotoxicosis in the peripregnancy period present specific challenges. In making management decisions, it is essential to weigh the risks and benefits of treatments not just for the mother but also for the fetus and for breastfed infants. A team approach to management is critical, with close collaboration among endocrinologists, maternal-fetal medicine specialists, and neonatologists.

ABBREVIATIONS

GD = Graves disease; hCG = human chorionic gonadotropin; MMI = methimazole; PPT = postpartum thyroiditis; PTU = propylthiouracil; T3 = triiodothyronine; T4 = thyroxine; TBG = thyroxine-binding globulin; TRAb = TSH receptor antibody; TSH = thyroid-stimulating hormone.

Crosstalk between gonadotropins and thyroid axis

Gonadotropins and thyroid hormones are essential, respectively, for reproduction and metabolism. The classical endocrinological approach is based on the detection of axes that start from the hypothalamus and arrive at the final effector organ, in this case gonads and thyroid. However, several clues suggest that these axes do not work in parallel, but they dialogue with each other. In this article, we review evidences demonstrating crosstalk between gonadotropins and thyroid axis. Firstly, there is an undeniable structural similarity of both hormones and receptors, maybe due to a common ancient origin. This structural similarity leads to possible interaction at the receptor level, explaining the influence of thyroid stimulating hormone on gonadal development and vice versa. Indeed, altered levels of thyroid hormones could lead to different disorders of gonadal development and function throughout entire life, especially during puberty and fertile life. We here report the current knowledge on this item both in males and in females. In particular, we deepen the interaction between thyroid and gonads in two situations in females: polycystic ovary syndrome, the most frequent cause of menstrual alteration, and pregnancy.

Variations in CD14 Gene Are Associated With Autoimmune Thyroid Diseases in the Chinese Population

Autoimmune thyroid diseases (AITDs) are chronic organ-specific autoimmune diseases and mainly include Graves' disease (GD) and Hashimoto's thyroiditis (HT). CD14 is an important component of the immune system as a receptor for gram-negative lipopolysaccharide (LPS). The genetic polymorphisms of CD14 have been confirmed to be associated with a variety of autoimmune diseases. However, its relationship with AITDs is still unclear. The study was aimed to determine whether four single nucleotide polymorphisms (rs2915863, rs2569190, rs2569192, and rs2563298) of CD14 are associated with AITDs and its subgroups of GD and HT. The results showed significant association of rs2915863 and rs2569190 with GD. The frequencies of rs2915863 genotypes and T allele in patients with GD differed significantly from their controls (P = 0.007 and P = 0.021, respectively). For rs2569190, frequencies of genotypes and G allele in GD patients also showed positive P-values (P = 0.038 and P = 0.027, respectively). The correlations between these two loci and GD are more pronounced in female GD patients and patients with a family history. In genetic model analysis, the allele model, recessive model, and homozygous model of rs2569190 and rs2915863 embodied strong correlations with GD after the adjusting of age and gender (P = 0.014, P = 0.015, P = 0.009, and P = 0.014, P = 0.001, P = 0.006, respectively). However, these four sites are not related to HT. We firstly discovered the relationship between CD14 gene polymorphism and GD, and the results indicate that CD14 is an important risk locus for AITD and its SNPs may contribute to host's genetic predisposition to GD.