Thyroid autoimmunity and obstetric outcomes in women with recurrent miscarriage: a case-control study

Effect of anti-thyroid antibodies on recurrent miscarriage: A meta-analysis

SETTING

Previous studies addressed the association between anti-thyroid antibodies and recurrent miscarriage (RM), however, the role of anti-thyroid antibodies in RM patients is debatable.

OBJECTIVES

Therefore, we conducted this meta-analysis and the aim of this current study was to assess whether anti-thyroid peroxidase (anti-TPO) and/or anti-thyroglobulin (anti-TG) antibody positivity was associated with RM.

DESIGN

A meta-analysis was conducted.

PARTICIPANTS

Recurrent miscarriage patients.

METHODS

STATA 12.0 software were applied to compute odds ratios (ORs)/relative risks (RRs) and 95% CIs regarding association between anti-TPO and anti-TG antibodies and the prevalence of RM.

RESULTS

N = 28 studies (8875 participants) explored effect of anti-thyroid antibodies on RM. Analysis of the 28 studies revealed significant association between anti-TPO, anti-TG antibodies and the prevalence of RM with a random effects model (OR/RR = 2.02; 95% CI: 1.63-2.51, p < 0.001; I2 = 44.3%, p value for Q test = 0.004). Analysis of the 20 studies revealed significant association between anti-TPO antibodies and the prevalence of RM with a random effects model (OR/RR = 1.59; 95% CI: 1.25-2.03, p < 0.001; I2 = 43.1%, p value for Q test = 0.022). Analysis of the 14 studies revealed significant association between anti-TG antibodies and the prevalence of RM with a random effects model (OR/RR = 2.25; 95% CI: 1.56-3.23, p < 0.001; I2 = 49.2%, p value for Q test = 0.019).

CONCLUSIONS

Based on the currently available analysis, our findings suggest that women with anti-TPO and/or anti-TG antibodies have a higher risk of RM than that in negative antibody women. Further investigation is needed to better clarify the exact role of the anti-thyroid antibodies in RM and whether treatment is of benefit.

LIMITATIONS

First, differences from various detection methods and reagents used in different studies may affect the diagnostic interpretation of anti-thyroid antibodies, which might influence the accuracy of this meta-analysis. Second, positive anti-thyroid antibodies seem likely to be part of a more general disorder of maternal immune system, due to restrictions of funding and condition, a complete autoantibody screening investigation is hardly to conduct in all participants, and this could be a possible limitation of all included studies. Third, there is no mention of thyroxine therapy on RM, making the meta-analysis even more limited.

Update on therapeutic use of levothyroxine for the management of hypothyroidism during pregnancy

Hypothyroidism is a relatively common finding during pregnancy. This may be due either to the presence of existing thyroid disease and/or to the increased demands that pregnancy places the thyroid gland to provide thyroid hormones for the mother and the developing fetus. There is no doubt that overt hypothyroidism is associated strongly with adverse pregnancy outcomes, including miscarriage. Meta-analyses show that thyroid hormone replacement with levothyroxine (LT4) reduces the risk of adverse pregnancy outcomes in the setting of overt hypothyroidism. Accordingly, management guidelines in this area are unanimous in recommending intervention with to control the level of thyrotropin (TSH) to below 2.5 μIU/mL. The evidence for an adverse impact of subclinical hypothyroidism (SCH) on pregnancy outcomes is less clear, although meta-analyses suggest that SCH reduces the chance of a successful pregnancy outcome. Guidelines also support intervention for some patients with SCH, particularly where TSH is high (>10 μIU/mL), or where TSH is above its trimester-specific reference range in a woman with thyroid autoimmunity (giving LT4 to euthyroid women with thyroid autoimmunity is not supported). Real-world evidence suggests that hypothyroidism in pregnancy is often overlooked or that LT4 is not given appropriately to gain tight control of TSH. More research is needed to identify the barriers to optimal thyroid care with LT4 at this crucial time.

Optimizing levothyroxine treatment for subclinical hypothyroidism during pregnancy

The onset of pregnancy places additional stress of the thyroid gland, which must produce additional thyroid hormones to support the developing foetus. Hypothyroidism, including subclinical hypothyroidism (SCH), may appear de novo at this time, or existing thyroid disease may become more severe. Accordingly, SCH is a relatively common complication of up to about 3% of pregnancies, with higher rates in some areas. There is strong evidence from systematic reviews and meta-analyses that uncontrolled SCH is associated with an increased risk of adverse pregnancy outcomes, including miscarriage, preeclampsia, and gestational diabetes. The evidence base also suggests that treatment with levothyroxine (LT4), optimized to control thyrotropin (TSH) to within its pregnancy-specific reference ranges reduces these risks. Current management guidelines provide a clear framework of intervention with LT4 in pregnant women with SCH, especially where TSH is high or where thyroperoxidase autoantibodies are present. Sub-optimal adherence to LT4 is common: it is important that patients take their LT4 correctly and that treating physicians and/or healthcare professionals manage these patients according to the latest management guidelines. The titration of LT4 is likely to occur within a range of LT4 daily doses between 25 µg and 75 µg for the majority of this population. LT4 is a narrow therapeutic index drug and small variations in dosage may produce a clinically significant change in thyroid status. Newer formulations of LT4, engineered to provide more precise and consistent dosing, and with a broad range of tablet strengths, may facilitate the precise titration of the LT4 dose for these patients.

Raised First Trimester Thyroid Peroxidase Antibodies May Predict First Trimester Miscarriage: A Case Control Study

Miscarriages constitute a significant aspect of failed pregnancies and a source of worry for the patient and caregiver. Some of the causes of miscarriages remain unknown. Immunological conditions such as thyroid autoimmunity could play significant roles. Our objective was to determine the relationship between raised thyroid peroxidase antibodies and first trimester miscarriages in a low resource setting. This was a case control study at the Gynaecological Clinic of the University of Calabar Teaching Hospital, Nigeria; from 14th February 2020 to 13th January 2021, involving 145 cases who had first trimester miscarriages, and their matched controls who had apparently normal pregnancies, at same gestational ages. Sera of venous blood from both participants and controls were analysed for thyroid peroxidase antibodies using enzyme-linked immunosorbent assay, and analysed using SPSS version 20, and GraphPad Prism 8.4.3 statistical software. Being a civil servant and low social status had significant odds for first trimester miscarriage. Raised thyroid peroxidase antibodies in the first trimester had 10-fold odds for miscarriage. Odds ratio 10.34, 95% CI: 3.22 to 32.98, P-value = 0.0001. The test had a sensitivity of 89.66% and specificity of 54.41%. The positive predictive value was 17.93%, while the negative predictive value was 97.93% and a likelihood ratio of 1.966. Rising thyroid peroxidase antibodies in early pregnancy could be a predictor for miscarriage. This is so because patients with raised thyroid peroxidase antibodies in the first trimester had a 10-fold risk of having a first trimester miscarriage.

Influence of thyroid autoimmunity at various clinical stages of hypothyroidism on the risk of miscarriage before 20 weeks of gestation

PURPOSE

We aimed to clarify the influence of thyroid autoantibodies at various clinical stages of hypothyroidism on the risk of pregnancy loss before 20 weeks of gestation.

METHODS

We enrolled 230 pregnant women with a history of recurrent miscarriage. Detailed clinical history, physical examination, and laboratory testing of thyroid function, antithyroid peroxidase (anti-TPO), and antithyroglobulin (anti-TG) were applied among all participants.

RESULTS

Coexisting overt hypothyroidism and positive thyroid autoantibodies quadrupled the risk of miscarriage in women before 20 weeks of gestation (OR 4.04, 95% CI = 2.08-7.96, P < 0.001). Women with subclinical hypothyroidism (OR 1.44, 95% CI = 0.81-2.57, P = 0.132,) or who were euthyroid (OR 1.53, 95% CI = 0.86-2.73, P = 0.094) showed a non-significant risk of miscarriage even with positive thyroid autoantibodies. Thyroid-stimulating hormone (TSH) was positively correlated with the number of miscarriages rather than anti-TPO (P < 0.001 and 0.209, respectively).

CONCLUSION

Coexistence of overt hypothyroidism and thyroid autoimmunity was the only significant driver of pregnancy loss before 20 weeks of gestation.

Recurrent MiscarriageGreen-top Guideline No. 17

In this guideline, recurrent miscarriage has been defined as three or more first trimester miscarriages. However, clinicians are encouraged to use their clinical discretion to recommend extensive evaluation after two first trimester miscarriages, if there is a suspicion that the miscarriages are of pathological and not of sporadic nature. Women with recurrent miscarriage should be offered testing for acquired thrombophilia, particularly for lupus anticoagulant and anticardiolipin antibodies, prior to pregnancy. [Grade C] Women with second trimester miscarriage may be offered testing for Factor V Leiden, prothrombin gene mutation and protein S deficiency, ideally within a research context. [Grade C] Inherited thrombophilias have a weak association with recurrent miscarriage. Routine testing for protein C, antithrombin deficiency and methylenetetrahydrofolate reductase mutation is not recommended. [Grade C] Cytogenetic analysis should be offered on pregnancy tissue of the third and subsequent miscarriage(s) and in any second trimester miscarriage. [Grade D] Parental peripheral blood karyotyping should be offered for couples in whom testing of pregnancy tissue reports an unbalanced structural chromosomal abnormality [Grade D] or there is unsuccessful or no pregnancy tissue available for testing. [GPP] Women with recurrent miscarriage should be offered assessment for congenital uterine anomalies, ideally with 3D ultrasound. [Grade B] Women with recurrent miscarriage should be offered thyroid function tests and assessment for thyroid peroxidase (TPO) antibodies. [Grade C] Women with recurrent miscarriage should not be routinely offered immunological screening (such as HLA, cytokine and natural killer cell tests), infection screening or sperm DNA testing outside a research context. [Grade C] Women with recurrent miscarriage should be advised to maintain a BMI between 19 and 25 kg/m2 , smoking cessation, limit alcohol consumption and limit caffeine to less than 200 mg/day. [Grade D] For women diagnosed with antiphospholipid syndrome, aspirin and heparin should be offered from a positive test until at least 34 weeks of gestation, following discussion of potential benefits versus risks. [Grade B] Aspirin and/or heparin should not be given to women with unexplained recurrent miscarriage. [Grade B] There are currently insufficient data to support the routine use of PGT-A for couples with unexplained recurrent miscarriage, while the treatment may carry a significant cost and potential risk. [Grade C] Resection of a uterine septum should be considered for women with recurrent first or second trimester miscarriage, ideally within an appropriate audit or research context. [Grade C] Thyroxine supplementation is not routinely recommended for euthyroid women with TPO who have a history of miscarriage. [Grade A] Progestogen supplementation should be considered in women with recurrent miscarriage who present with bleeding in early pregnancy (for example 400 mg micronised vaginal progesterone twice daily at the time of bleeding until 16 weeks of gestation). [Grade B] Women with unexplained recurrent miscarriage should be offered supportive care, ideally in the setting of a dedicated recurrent miscarriage clinic. [Grade C].

The role of thyroid function in female and male infertility: a narrative review

PURPOSE

We herein aimed to review the new insights into the impact of impaired thyroid function on male and female fertility, spacing from spontaneous pregnancy to ART, with the objective of providing an updated narrative revision of the literature.

METHODS

This narrative review was performed for all available prospective, retrospective and review articles, published up to 2021 in PubMed. Data were extracted from the text and from the tables of the manuscript.

RESULTS

Thyroid dysfunction is frequently associated with female infertility, whereas its link with male infertility is debated. Female wise, impaired function is detrimental to obstetric and fetal outcomes both in spontaneous pregnancies and in those achieved thanks to assisted reproduction technologies (ART). Furthermore, the reference range of TSH in natural pregnancy and ART procedures has recently become a matter of debate following recent reports in this field. On the other hand, the impact of thyroid function on the male reproductive system is less clear, although a possible role is suggested via modulation of Sertoli and Leydig cells function and spermatogenesis.

CONCLUSION

Thyroid function should be carefully monitored in both male and female, in couples seeking spontaneous pregnancy as well as ART, as treatment is generally immediate and likely to improve chances of success.

Anti-thyroid antibodies and underlying generalized immunologic aberrations in patients with reproductive failures

The link between autoimmune thyroid diseases and reproductive failures, including implantation failure and pregnancy loss, has been attracted a great deal of attention in the last two decades. In this regard, a considerable progress has been achieved in understanding the etiopathogenesis of the adverse pregnancy consequences related to the presence of anti-thyroid antibodies, however, the exact action mechanisms of these antibodies are not fully comprehended. Thyroid peroxidase antibodies (TPOAbs), thyroglobulin antibodies (TgAbs) and TSH receptor antibodies (TRAbs) are the anti-thyroid antibodies which are present in autoimmune thyroid disorder (AITD) patients, such as Hashimoto's thyroiditis. In this condition, the thyroid hormones production, which are essential for normal implantation and pregnancy, are disrupted, and compromise the embryo or fetus development. In addition, a hypothesis suggests that there is underlying generalized immune abnormalities behind the presence of these antibodies. On the other hand, similar immunologic aberrations have been observed in thyroid autoimmunity and reproductive complications, which are postulated to be the proper answer for the scientists who seek for the pathophysiology behind the presence of these antibodies. Elevated inflammatory responses and decreased immunoregulatory actions, seem to be the main interfering pathologic factors in maternal tolerance toward fetus. In addition, cross reactivity of these antibodies with antigenic determinants of egg, embryo and placenta is another suggested mechanism, causing implantation and pregnancy complications. The ability of anti-thyroid antibodies in passing through the placental barrier and affecting the fetal thyroid gland, makes them more threatening for maintenance of a pregnancy.

The findings about relationship between autoimmune thyroid disease and first-trimester aneuploidy results

Aim: The aim of this study was to investigate the relationship between thyroid autoantibody and first-trimester aneuploidy results. Thyroid autoimmunity (TAI) is the most common autoimmune disorder. Patients with TAI are usually euthyroid. Thyroid peroxidase (TPO-Ab) in patients with or without thyroid dysfunction is associated with infertility, recurrent embryo implantation failure, and early pregnancy loss. The impact of TPO-Ab on first-trimester aneuploidy test results needs to be studied. Material and Method: This retrospective case-control study was conducted between December 2019 and May 2022. Patients with thyroid autoantibody positivity (n=112) were included in the study as the case group. The control group was selected from age and body mass index (BMI)-matched patients (n=130). Nuchal translucency (NT), crown rump length (CRL), pregnancy-associated plasma protein A (PAPP-A) and free beta subunit of human chorionic gonadotropin (β-hCG)) values were compared between the two groups. Results: This study included two hundred forty two age-matched (29.86±4.51) and BMI-matched (23.96±2.34) women. There was no statistically significant difference between groups in terms of free thyroxine (FT4), PAPP-A and free β-hCG (p>0.05). NT as a marker for major chromosomal defects and CRL were comparable in case and control groups (p>0.05). Conclusion: There is no statistically significant relationship between thyroid autoimmune diseases and the first-trimester aneuploidy results.

Levothyroxine treatment for subclinical hypothyroidism improves the rate of live births in pregnant women with recurrent pregnancy loss: a randomized clinical trial

Objective: This study aimed to assess whether the use of levothyroxine was beneficial in pregnant women with subclinical hypothyroidism (SCH) or women who were positive for thyroid peroxidase antibody (TPOAb⁺).Study design: This was a randomized clinical trial involving 1736 populations of pregnant women. Our study was conducted into two groups: normal pregnant group and recurrent pregnancy loss (RPL) pregnant group. Both patients were divided into SCH and TPOAb⁺ groups, respectively; the patients of four groups were randomized into either the L-T4 treatment or control groups.Results: There was no significant difference between the two groups in the prevalence of SCH and TPOAb⁺ (p > .05); The live births rate of normal pregnant group was higher than that of the RPL pregnant Group (79.5% vs. 70.8%, p < .05); Considering normal pregnant women, whether women who were TPOAb ⁺ or SCH, there was no significant difference between the treatment and control group in the live birth rate and the pregnancy loss rate. In RPL group, whether women who were TPOAb⁺ or SCH, L-T4 treatment can obtain higher live birth rate and lower abortion rate compared to the control.Conclusion: There was no significant difference between normal and RPL pregnant women in the prevalence of SCH and TPOAb⁺.Treatment with L-T4 decreased the risk of pregnancy loss and increased the live birth rate in RPL pregnant women who were positive for TPOAb or subclinical hypothyroidism. Levothyroxine therapy is recommended for SCH and TPOAb⁺ women in pregnant women with recurrent pregnancy loss.

Levothyroxine Supplementation in Euthyroid Pregnant Women With Positive Autoantibodies: A Systematic Review and Meta-Analysis

OBJECTIVES

To explore the role of levothyroxine (LT4) supplementation in affecting the outcome of pregnant euthyroid women with thyroperoxidase (TPO) antibodies.

METHODS

MEDLINE, EMBASE, Google Scholar, and the Web of Science databases were searched. The primary outcome was pre-term birth (PTB), defined as live birth before 37 weeks of gestation; secondary outcomes were gestational hypertension, pre-eclampsia (PE), placental abruption, miscarriage, intra-uterine death (IUD), and admission to neonatal intensive care unit (NICU). All these outcomes were explored in euthyroid women with TPO antibodies receiving compared to those not receiving LT4 supplementation in pregnancy. Random-effect meta-analyses were used to analyze the data and results reported as pooled odds ratios (OR) with their 95% confidence intervals (CI).

RESULTS

The risk of PTB was lower in women with TPO antibodies receiving compared to those not receiving LT4 supplementation (OR of 0.60 (95% CI 0.4-0.9). However, this association came mainly from observational studies (OR: 0.29, 95% CI 0.1-0), while RCTs did not show any beneficial effect of LT4 supplementation in affecting such outcomes. Conversely, there was no difference in the risk of gestational hypertension, preeclampsia, placental abruption, miscarriage, and admission to NICU between the two groups.

CONCLUSIONS

LT4 supplementation in TPO euthyroid women is not associated with a reduced risk of PTB in TPO-positive women with normal thyroid function.

Thyroid autoimmunity and reproduction: Bidirectional relationship that continues to intrigue

Today, infertility is not only a serious health but also a psycho-social problem, one that is on the rise in the world. Thyroid autoimmunity (TAI) is the most common disease of the thyroid gland in the reproductive period, which can affect spontaneous conception as well as conception through assisted reproduction technology (ART), but also the maintenance of healthy pregnancy. It can also cause numerous maternal and fetal complications. There is a wide array of publications on the topic of the mechanisms of association between TAI and reproduction, with the question of whether thyroid autoantibodies are solely tissue-specific antibodies, whether and when to start levothyroxine treatment, and that we require more fundamental research on the direct effect of thyroid autoantibodies starting from folliculogenesis to embryogenesis and implantation as well as the post-implantation embryo development, but also the composition of the follicular fluid as a microenvironment of enormous importance for the maturation of the oocytes which thyroid autoantibodies reach via the blood-follicle barrier.

Thyroid Autoimmunity in Adverse Fertility and Pregnancy Outcomes: Timing of Assisted Reproductive Technology in AITD Women

Thyroid autoimmunity (TAI) is prevalent in women of live-birthing age and has independently been associated with complications of fertility and pregnancy, in the case of spontaneous conception or after assisted reproductive technology (ART) treatment. However, it remains challenging to identify causation between infertility and TAI, even interventional trials looking at the impact of levothyroxine (LT4) treatment on fertility and pregnancy outcomes due to differences among study results which related to small scales, impropriate study designs, enrollment criteria of infertility cause and titer/hormone concentration measurements. Furthermore, many questions remain unsettled in ART management in AITD infertile women attempt pregnancy. Therefore, further observational and interventional trials are needed more comprehensive multiple-center, double blinded, and randomized.

Recent insights into the impact of immune dysfunction on reproduction in autoimmune thyroiditis

Autoimmune thyroiditis (AIT) is a common organ-specific autoimmune disease with a high incidence among women of childbearing age. Recent studies have reported that women with AIT are more susceptible to infertility, miscarriage and preterm birth. It has been investigated that abnormal changes in maternal immune system and maternal-fetal interface can dampen the immune tolerance between mother and fetus, which underlie the pathogenesis of adverse pregnancy outcomes. Hence, we summarize the immunological changes related to adverse reproductive outcomes in AIT and highlight the respective contributions of both humoral and cellular immune dysfunctions to pregnancy failures. Moreover, the direct impacts of AIT on maternal-fetal immune activation and biological influences to trophoblasts are discussed as well. All these associations require confirmation in larger studies, and the pathogenic mechanisms need to be better understood, which might provide useful information for clinical diagnosis and therapy of AIT.

TPO antibody positivity and adverse pregnancy outcomes

Thyroid autoimmunity (TAI) is prevalent amongst women of reproductive age. TAI describes the presence of circulating anti-thyroid autoantibodies that are targeted against the thyroid, with or without thyroid dysfunction. Thyroid peroxidase antibodies (TPOAb) are the most common anti-thyroid autoantibodies. Around 10% of biochemically euthyroid individuals also have an elevated TPOAb titre. Many studies have linked the presence of TPOAb to adverse maternal and fetal outcomes in pregnancy, in particular miscarriage and pre-term birth, even in the absence of thyroid dysfunction. The causal pathway is poorly understood and few trials have looked to find treatments to reduce adverse outcomes. This review discusses in detail the associated adverse outcomes of TPOAb in pregnancy and the results of trials exploring methods to reduce such outcomes. Recommendations for counselling and monitoring of women with TPOAb and suggested areas for future work are also outlined.

Effect of antithyroid antibodies on women with recurrent miscarriage: A meta-analysis

Problem

The effect of thyroid autoimmunity (TAI) on the prevalence of recurrent miscarriage (RM) is highly debatable. No meta‐analysis has been published in the past decade to investigate the impact of TAI on women with RM.

Method of Study

Systemic literature search was conducted on PubMed, Embase, Cochrane, and Web of Science databases. English language literatures published between 1993 and 2019 were selected. We assessed the relationship between the prevalence of RM and thyroid peroxidase antibodies (TPO‐Ab) or antithyroid antibodies (ATA) and evaluated the thyroid‐stimulating hormone (TSH) level in TPO‐Ab‐positive women with RM. We also observed the treatment effect with levothyroxine (LT4) for RM. Review Manager 5.3 software was used to obtain the pooled odds ratios (OR).

Results

Analysis of 22 eligible studies revealed significant association between TPO‐Ab and the prevalence of RM (OR = 1.85; 95% CI, 1.38 to 2.49; P < .001)(n ≥ 3), (OR = 1.82; 95% CI, 1.13 to 2.92; P = .01) (n ≥ 3). Women with ATA + had higher risk of RM (OR = 2.36; 95% CI, 1.71 to 3.25; P < .00001)(n ≥ 3), (OR = 2.34; 95% CI, 1.70 to 3.22; P < .00001)(n ≥ 2). RM women with TPO‐Ab had higher TSH level when compared with those negative for TPO‐Ab (random‐effect SMD = 0.60; 95% CI, 0.31 to 0.90; P < .0001). We also found beneficial effects of LT4 supplementation on the outcome of live birth rate (LBR) among pregnant women with TPO‐Ab (OR = 3.04; 95% CI, 0.69 to 13.36; P = .14).

Conclusion

The presence of serum antithyroid antibodies does harms to women and can even lead to recurrent miscarriage; LT4 treatment may have beneficial to RM women.

The correlation of thyroid autoimmunity and peripheral and uterine immune status in women with recurrent miscarriage

PROBLEM

Thyroid autoimmunity (TAI), which is the most prevalent cause of thyroid dysfunction in women of reproductive age, is associated with increased risk of miscarriages and adverse pregnancy outcomes. However, the exact pathophysiology of TAI is still unknown. We aim at investigating the relationship between TAI and the peripheral and uterine immune markers in women with recurrent miscarriage (RM).

METHOD OF STUDY

Peripheral blood and endometrial tissue samples were collected during mid-luteal phase of 242 RM women to evaluate the prevalence of TAI, the thyroid function, the percentages of peripheral blood and endometrial lymphocytes, the levels of peripheral blood T helper 1 (Th1) cytokine and natural killer (NK) cell cytotoxicity.

RESULTS

There was no relationship between TAI and peripheral immune parameters. However, the percentage of endometrial Regulatory T (Treg) cells was significantly higher in RM women who were thyroid antibody positive than in those who were antibody negative (p ＜ 0.05).

CONCLUSION

Thyroid antibody positivity seems to be part of a more generalized immune dysfunction. The increased endometrial Treg cells in RM patients with TAI may ameliorate coincidental TAI during pregnancy by linked suppression and prevent the over-reactive status of the immune system.

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.

Evaluating the role of paternal factors in aetiology and prognosis of recurrent pregnancy loss: study protocol for a hospital-based multicentre case-control study and cohort study (REMI III project)

INTRODUCTION

Recurrent pregnancy loss (RPL) is defined as the spontaneous demise of two or more pregnancies before the fetus reaches viability. Despite investigation of multiple known maternal risk factors, in more than 50% of couples, this condition remains unexplained. Studies focusing on paternal factors in RPL are scarce, and therefore, paternal evaluation in RPL is currently very limited. However, regarding single miscarriage, there are multiple publications suggesting a contributive role of paternal factors. In this project, we aim to identify paternal factors associated with RPL and to improve couple-specific prediction of future pregnancy outcomes by developing a prediction model containing both maternal and paternal factors.

METHODS AND ANALYSIS

In a case-control design, the relation between unexplained RPL and paternal age, lifestyle factors, sperm DNA damage and immunomodulatory factors in peripheral blood and semen will be studied. Prospectively, 135 couples with naturally conceived unexplained RPL (cases) and 135 fertile couples without a history of pregnancy loss (controls) will be included, with collection of paternal blood and semen samples and documentation of clinical and lifestyle characteristics. In addition, 600 couples from both groups will be included retrospectively. To adjust for confounders, multivariate logistic regression will be used. The predictive value of paternal and maternal factors will be studied in the total RPL cohort consisting of approximately 735 couples. The primary outcome of the cohort study is live birth within 5 years after initial visit of the clinic. Secondary outcomes are ongoing pregnancy, time interval until next pregnancy and pregnancy complications.

ETHICS AND DISSEMINATION

This project is approved by the Medical Research Ethics Committee of the Leiden University Medical Center. No risks or burden are expected from the study. The findings of this study will be disseminated via peer-reviewed publications and presentations at international conferences.

TRIAL REGISTRATION NUMBER

NL7762.

Thyroid Peroxidase Antibodies and Prospective Live Birth Rate: A Cohort Study of Women with Recurrent Pregnancy Loss

Background: Thyroid autoimmunity has been associated with pregnancy loss. Suggested mechanisms include thyroid function aberrations or an underlying breach of immunotolerance. We hypothesized that thyroid autoimmunity is a marker of the latter in women with recurrent pregnancy loss. This study investigated thyroid peroxidase antibody (TPOAb) status as a predictor of live birth in women with unexplained recurrent pregnancy loss. Methods: Cohort study of 825 consecutive women with recurrent pregnancy loss followed at the tertiary referral center for Recurrent Pregnancy Loss, Copenhagen University Hospital (Rigshospitalet), from 2011 to 2017. Recurrent pregnancy loss was defined as ≥3 consecutive losses, and as unexplained by absence of antiphospholipid syndrome, parental chromosome abnormality, or uterus malformation. Upon first visit, all women were screened for thyrotropin (TSH) and TPOAbs (TPOAb positivity: ≥60 kIU/L). Adjusted logistic regression analyses included as covariates the following: maternal age, TSH, previous number of losses, body mass index, smoking, pregnancy achieved by assisted reproductive technology, and thyroxine replacement (T4) treatment. Results: We included 825 women with a total of 3246 previous losses, of whom 139 (16.8%) were TPOAb positive. TPOAb positivity was not associated with the previous number of losses (p = 0.41). Women with unexplained recurrent pregnancy loss had a live birth rate in the first pregnancy after referral of 62.8% (285 of 454). TPOAb positivity was found in 78 of 454 (17.2%) women and was associated with a reduced live birth rate (51.3% vs. 65.2%, p = 0.02, adjusted odds ratio [aOR] 0.2 [0.1-0.6] p = 0.001). Treatment with T4 increased live birth rate significantly (aOR 3.7 [1.4-9.8], p = 0.007), and TPOAb-positive women receiving T4 had a live birth rate similar to that of TPOAb-negative women not receiving T4 (p = 0.70). Only 30% of TPOAb-positive women and 39% of women treated with T4 during pregnancy had known thyroid disease at referral. Conclusion: In a large cohort of women with unexplained recurrent pregnancy loss, TPOAb positivity was predictive of a reduced live birth rate. However, T4 treatment improved odds of live birth. The study supports screening for TPOAbs as a risk factor in women with unexplained recurrent pregnancy loss. The beneficial effect of T4 treatment in this high-risk group needs confirmation by randomized controlled trials. Close collaboration between fertility experts and endocrinologists is paramount.

Risk Factors and Outcomes of Recurrent Pregnancy Loss in Japan

AIM

To clarify the risk factors and pregnancy outcomes for each risk factor of recurrent pregnancy loss (RPL) in Japan.

METHODS

Using a prospective RPL database collected from 16 facilities in Japan, the prevalence of risk factors for RPL, their treatments and pregnancy outcomes were examined.

RESULTS

Of 6663 patients registered in our database, 5708 patients had RPL. All examinations for risk factors were performed for 1340 patients (23.5%). The prevalences of positive antiphospholipid antibodies (aPL), malformation of the uterus, thyroid dysfunction, parental karyotype abnormality, factor XII deficiency, protein S deficiency and unknown risk factors were 8.7%, 7.9%, 9.5%, 3.7%, 7.6%, 4.3% and 65.1%, respectively. Although factor XII deficiency and protein S deficiency are not recognized as risk factors for RPL in general, low-dose aspirin (LDA) or unfractionated heparin + LDA therapy improved live birth rates. In transiently aPL-positive patients, the live birth rate with LDA therapy was similar to that with heparin + LDA. For unknown risk factors of RPL, the live birth rate in normal fetal karyotype in the none treatment group was similar to that in all other treatments group (81.3% vs 86.0%). Of 5708 RPL patients, pregnancy outcomes were known for 2261 patients and 1697 patients (75.1%) had at least one live birth.

CONCLUSION

The risk factors and pregnancy outcomes for each risk factor of RPL are useful for clinicians and patients. Factor XII deficiency and protein S deficiency may be risk factors of RPL.

Thyroid function reference ranges during pregnancy in a large Chinese population and comparison with current guidelines

Background:

A correct thyroid function reference range is important for the accurate diagnosis of thyroid disease during pregnancy. However, there is no consensus on whether thyroid function reference ranges in Chinese population should follow the America Thyroid Association (ATA) guidelines. This study aimed to establish a thyroid function reference range more suited to the Chinese population by evaluating the current thyroid function reference range in pregnant Chinese women and comparing it to the ATA guidelines.

Methods:

A total of 52,027 pregnant women were enrolled from January 2013 to December 2016. Thyroid stimulating hormone (TSH), free thyroxine (FT4), and thyroid peroxidase antibody (TPOAb) levels were tested during the first and third trimesters of pregnancy. Reference ranges of TSH and FT4 were established from the 2.5th and 97.5th percentiles of the TPOAb-negative population of women. The Mann-Whitney U test was used to compare thyroid hormones between the TPOAb-positive and TPOAb-negative groups.

Results:

We obtained that the TSH reference ranges were 0.03 to 3.52 mU/L and 0.39 to 3.67 mU/L, and the FT4 reference ranges were 11.7 to 19.7 pmol/L and 9.1 to 14.4 pmol/L, in the first and third trimester, respectively. If we used the 2011 ATA criteria about 7.0% and 4.0% pregnant women would be over diagnosed in first and third trimester, respectively, compared with local population thyroid hormone reference. When we compared our local criteria with the new 2017 ATA criteria, about 1.2% and 0.8% pregnant women would have a missed diagnosis in first and third trimester, respectively.

Conclusions:

Based on our data, which is in line with the current ATA guidelines, a population-based thyroid function reference range would be the first choice for diagnosis of thyroid disease during pregnancy in China. In case such population-based thyroid function reference ranges are unavailable in the east of China, our reference ranges can be adopted, if the same assay is used.

Trial Registration:

www.chictr.org.cn (No. ChiCTR1800014394).

Endocrine causes of recurrent pregnancy loss

OBJECTIVE

To review the available data on endocrine disorders and recurrent pregnancy loss.

FINDINGS

Our group found that most endocrine disorders do not seem to be correlated with a diagnosis of recurrent pregnancy loss (RPL). The exception to this is testing for thyroid stimulating hormone and thyroid antibodies, which is recommended due to a strong correlation with recurrent pregnancy loss and positive anti-thyroid peroxidase antibodies.

CONCLUSION

The available literature supports testing thyroid function and antibodies in women with RPL. Testing for other endocrine disorders is only warranted if otherwise clinically indicated, independent from a history of recurrent pregnancy loss.

Autoimmune thyroid disease during pregnancy

Understanding of changes in thyroid function and the consequences of thyroid disease during pregnancy has rapidly grown in the past two decades, and revised American Thyroid Association guidelines on this topic were published in 2017. This Review explores the association between thyroid autoimmunity and complications during and after pregnancy. Thyroid autoimmunity refers to the presence of antibodies to thyroperoxidase or thyroglobulin, or thyroid-stimulating hormone receptor antibodies (TRAbs), or a combination of these, and is present in up to 18% of pregnant women. Thyroid antibodies in pregnant women with normal functioning thyroids (ie, euthyroid) have been associated with several complications, including miscarriage and premature delivery. Treatments to improve pregnancy outcomes are being studied. Whether thyroid antibodies are associated with infertility and assisted reproductive technology outcomes is unclear; although, treatment with low doses of levothyroxine, which is usually used to treat hypothyroidism, can be considered in such situations. Additionally, thyroid antibodies have been associated with other neonatal and maternal complications. All these associations require confirmation in larger prospective studies, and their pathogenic mechanisms need to be better understood. Post-partum thyroiditis is substantially more frequent in women who have thyroid antibodies during pregnancy than in those who do not have thyroid antibodies; however, whether treatment can prevent post-partum thyroiditis in women who are or have been antibody positive is unknown. Finally, TRAbs cross the placenta from the mother to the fetus and can cause fetal or neonatal hyperthyroidism. Therefore, women who are positive for TRAbs during pregnancy should be monitored.

The role of levothyroxine in obstetric practice

Thyroid hormones play a pivotal role in somatic growth, metabolic regulation and neurodevelopment. There is growing evidence regarding adverse obstetric and perinatal consequences of maternal thyroid hypofunction during early stages of pregnancy. These include: early pregnancy loss, preterm delivery and lower intelligence quotient (IQ) in children. Different clinical guidelines have been published by scientific societies for the management of thyroid diseases during pregnancy and levothyroxine (LT₄) has become a therapeutic agent increasingly prescribed by obstetricians. The aim of this work was to search for both similarities and controversial clinical aspects from the currently available literature. Guidelines published from 2011 onwards have been analysed and compared, in order to clarify the evidence about the involvement of thyroid dysfunction in pregnancy complications and the impact of LT₄ use in their prevention and/or treatment. This review summarizes the most updated knowledge about the effectiveness of LT₄ for pregnancy complications, the current recommendations and its application into clinical practice. KEY MESSAGES The use of levothyroxine in obstetric practices requires a correct diagnosis and to consider the specific recommendations for each thyroid dysfunction entity. The effectiveness and safety of levothyroxine treatment in preventing adverse perinatal events in pregnant women with clinical hypothyroidism is supported by all the current guidelines. Levothyroxine therapy is strongly recommended in all cases of overt hypothyroidism and in cases of subclinical hypothyroidism associated to positive thyroid autoimmunity.

Identifying and treating subclinical thyroid dysfunction in pregnancy: emerging controversies

Thyroid hormones are essential for an adequate growth and development of the fetus. In addition to the classical association between maternal hypothyroidism and neurological impairment in the progeny, other adverse reproductive events have been associated with maternal thyroid dysfunction including infertility, miscarriage and preterm delivery. Although all scientific societies endorse the treatment of overt hypothyroidism; the management and/or treatment of subclinical hypothyroidism, hypothyroxinemia or antithyroid antibody-positive women should be considered with caution. Important trials have found no clear benefit of treatment of subclinical hypothyroidism in terms of cognitive outcomes; however, other interventional studies appear to reduce some of the obstetric and perinatal complications. As a result, the dilemma between universal screening or selective screening of women at high risk of thyroid dysfunction during pregnancy remains unresolved. Despite this, levothyroxine is also now regularly prescribed by gynaecologists and centres for reproductive medicine. In this context, there is increasing concern regarding the risk of over diagnosis and subsequent potential overtreatment. Taken together, we need to reconsider how thyroid dysfunction should be identified in pregnant women and highlight the arguments for and against the use of levothyroxine in obstetric practices. Our main findings: the mismatch between the guidelines recommendations and the use of LT4 in clinical settings as well as the disparity of criteria between scientific societies from different medical specialties. In conclusion, it is essential to reach agreements between both endocrinologists and obstetricians.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effects of levothyroxine treatment on pregnancy outcomes in pregnant women with autoimmune thyroid disease

BACKGROUND

Despite some studies indicating that thyroid antibody positivity during pregnancy has been associated with adverse pregnancy outcomes, evidence regarding the effects of levothyroxine (LT4) treatment of euthyroid/subclinical hypothyroid pregnant women with autoimmune thyroid disease on pregnancy outcome is limited. We aimed to assess whether pregnant women with autoimmune thyroid disease, but without overt thyroid dysfunction are affected by higher rates of adverse pregnancy outcomes. In addition, we aimed to explore whether LT4 treatment improves the pregnancy outcome of affected women.

METHODS

A prospective study was carried out on pregnant women from the first trimester to delivery. The study was conducted among pregnant women receiving prenatal care in centers under coverage of Shahid Beheshti University of Medical Sciences. Of a total of 1746 pregnant women, screened for thyroid dysfunction, 1028 euthyroid TPOAb-negative (TPOAb^-) and 131 thyroid peroxidase antibody-positive (TPOAb⁺) women without overt thyroid dysfunction entered the second phase of the study. TPOAb⁺ women were randomly divided into two groups: group A (n = 65), treated with LT4 and group B (n = 66), received no treatment. The 1028 TPOAb^- women (group C) served as a normal population control group. Primary outcomes were preterm delivery and miscarriage and secondary outcomes included placenta abruption, still birth, neonatal admission and neonatal TSH levels.

RESULTS

Groups A and C displayed a lower rate of preterm deliveries compared with group B (RR = 0.30, 95% CI: 0.1-0.85, P = 0.0229) and (RR = 0.23, 95% CI: 0.14-0.40, P < 0.001) respectively. There was no statistically significant difference in the rates of preterm labor between groups A and C (RR = 0.79, 95% CI: 0.30-2.09, P = 0.64). The number needed to treat (NNT) for preterm birth was 5.9 (95% CI: 3.33–25.16).

CONCLUSIONS

Treatment with LT4 decreases the risk of preterm delivery in women who are positive for TPOAb.

Endocrine dysfunction and recurrent spontaneous abortion: An overview

Miscarriage is the spontaneous loss of a fetus before it is viable, occurring at a rate of 15–20%. Recurrent spontaneous abortion (RSA) or habitual miscarriage is defined as repeated occurrence of 3 or more miscarriages before 20^th week of gestation accounting for the most common complication of early pregnancy in humans. Various etiological factors responsible for recurrent miscarriage are anatomical, genetical, endocrinological, immunological, and infectious. The endocrinological abnormalities may be polycystic ovarian syndrome, hyperprolactinemia, luteal phase defect, thyroid dysfunction, diabetes, or hyperandrogenism contributing to recurrent pregnancy loss. In the present article, the role of endocrinological disorders in patients with RSA has been reviewed. The article search was done using electronic databases, Google scholarly articles, and PubMed based on different key words. We have further combined the searches and made grouping as per various endocrine abnormalities, which might be responsible to cause spontaneous loss of fetus.

Thyroid and Pregnancy in Tehran, Iran: Objectives and Study Protocol

BACKGROUND

Thyroid dysfunction is the second most common endocrine disease in females of reproductive age. There are controversial data on the adverse effect of subclinical thyroid dysfunctions on adverse feto-maternal outcomes.

OBJECTIVES

The current study aimed to identify the prevalence of thyroid dysfunction during pregnancy and to assess the effectiveness of treatment with levothyroxine on pregnancy outcomes of females with thyroid autoimmunity with or without subclinical thyroid dysfunction in Tehran, Iran.

PATIENTS AND METHODS

The study encompassed two phases: 1) a population based cross sectional study using a cluster sampling method that screened first trimester pregnant females for thyroid disorders, 2) a double-blind randomized clinical trial to determine the effectiveness of levothyroxine on adverse pregnancy outcomes in females with thyroid autoimmunity with or without subclinical thyroid dysfunction. Pregnant females were assessed at their first prenatal visit for serum TSH, T4, T-uptake, TPOAb and urinary iodine following which they were classified as: 1) normal, 2) subclinical TPOAb negative and 3) subclinical/euthyroid TPOAb positive. Females in groups two and three were randomly divided into two groups: group A was treated with levothyroxine (LT4), and group B did not receive any treatment. There was a follow-up program for participants and rates of adverse pregnancy outcomes in the treated and untreated groups were measured.

RESULTS

Results of the study provided reliable information regarding the prevalence of thyroid dysfunction among females in Tehran using universal thyroid screening, along with identification of the iodine status of their community. The study aimed to determine whether LT4 treatment exerts beneficial effects in females without overt thyroid dysfunction.

Effects of isolated positive maternal thyroglobulin antibodies on brain development of offspring in an experimental autoimmune thyroiditis model

BACKGROUND

Autoimmune thyroiditis (AIT) is a very common endocrine disorder in pregnancy. However, the effect of maternal positive thyroglobulin antibodies (TgAb) on brain development of offspring remains unclear. This study used an experimental autoimmune thyroiditis model in CBA/J mice and determined whether isolated positive maternal TgAb directly affected learning and memory abilities of offspring.

METHODS

An experimental autoimmune thyroiditis model was established in CBA/J mice through immunization with murine thyroglobulin (mTg). Measuring thyroid function and serum TgAb titer confirmed the presence of isolated positive maternal TgAb. Offspring serum TgAb titer, MCT8, Reelin, RC3, and BNDF mRNA expression in the brain, and brain histology were measured on postnatal days 0, 10, and 40 (PND0, PND10, PND40), and nerve cell migration (BrdU labeling) at PND40. Morris water maze, long-term potentiation (LTP), and LTP-related factor ERK1/2 levels were measured at PND40 to determine offspring spatial learning and memory development.

RESULTS

Maternal serum TgAb titers increased and remained elevated through pregnancy compared to controls. Thyrotropin and thyroid hormone levels were normal. The T group offspring (Tg immunized) had higher TgAb titers than the control (C) group. However, antibody titers time-dependently decreased. MCT8, Reelin, RC3, and BDNF mRNA expression in the whole brain were similar in the T and C groups on PND0, PND10, and PND40. Neuronal distribution and BrdU from the cerebral cortex and hippocampus were similar in the T and C group offspring. Morris water maze tests, excitatory postsynaptic field potentials, and ERK1/2 levels were also similar between the T and C groups.

CONCLUSIONS

Isolated positive maternal TgAb did not clearly influence the learning ability and memory of offspring, or nerve cell migration, despite a transient increase in TgAb in immunized mice.

Thyroid autoimmunity in pregnancy and its influences on maternal and fetal outcome in Iran (a prospective study)

AIM OF THE STUDY

Thyroid dysfunction and autoimmunity are common problems in women of child-bearing age. It could be associated with pregnancy morbidities in the mother and fetus. Due to lack of sufficient data about the prevalence of thyroid autoimmunity in pregnant women in Iran, and controversies about its complications on pregnancy outcomes, this study was conducted.

MATERIALS AND METHODS

This is a prospective study on 600 singleton pregnant women in 15-28 weeks of pregnancy; they were residents of Fars province. We evaluated the prevalence of preeclampsia, intra-uterine growth retardation (IUGR), preterm delivery and low Apgar score and their association with TSH, thyroid peroxidase (TPO), and thyroglobulin (Tg) antibodies.

RESULTS

Prevalence of anti-TPO and anti-Tg positivity is 12.8% and 8.5% among Iranian pregnant women. Mothers with either positive TPO or Tg antibody have a higher risk of preeclampsia (p = 0.019), preterm delivery (p < 0.001), IUGR (p < 0.001), and low first minute Apgar score (p < 0.001). This association was independent of thyroid dysfunction for preterm delivery (RR = 5, p < 0.001), and low Apgar score neonates (RR = 8.8, p < 0.001), but this association for preeclampsia was due to thyroid dysfunction (RR = 3.7, p = 0.003). About IUGR in either TPO or Tg positive mothers, this association results from the additive effect of thyroid dysfunction and thyroid autoimmunity (RR = 8.3, p < 0.001). Cesarean section delivery was significantly higher in abnormal TSH/positive anti-Tg mothers (p = 0.045).

CONCLUSION

Thyroid autoimmunity independent of thyroid dysfunction could have significant adverse outcomes in the mother and fetus. Further investigation should be done to reveal the significance of screening and treating the thyroid autoimmunity during pregnancy.