Effect of levothyroxine on pregnancy outcomes in women with thyroid autoimmunity: a systematic review with meta-analysis of randomized controlled trials

The investigation and management of recurrent early pregnancy loss: a Canadian Fertility and Andrology Society clinical practice guideline

This guideline defines recurrent early pregnancy loss (REPL) as two or more losses that occur before 10 weeks gestational age and includes non-consecutive and biochemical losses. Investigations should be considered on an individual basis and may include an evaluation of genetic, anatomical, endocrinological, structural and male-associated factors. Based on the findings and available resources, options for management may include preimplantation genetic testing (PGT) for aneuploidies or PGT for chromosomal structural rearrangements, progesterone supplementation and supportive care. This guideline emphasizes a personalized approach to the problem of REPL, recognizing an overall promising prognosis for this patient population and the avoidance of treatment options that have not been shown to be of benefit.

Updates on thyroid disorders in pregnancy and the postpartum period

ABSTRACT

NPs play a pivotal role in caring for pregnant people. This article provides an overview of gestational and postpartum thyroid disorders, including their assessment, management, and indications for referral. The goal of this article is to help providers better assess and manage thyroid disorders during pregnancy and improve patient outcomes.

Impact of thyroid autoantibodies and serum TSH level on clinical IVF outcomes

OBJECTIVE

This study aimed to investigate the impact of thyroid autoantibodies and serum TSH levels on clinical IVF outcomes.

MATERIALS AND METHODS

This study included 260 Korean women scheduled for their first IVF between 2013 and 2017. Serum levels of thyroid hormone, TSH, and antibody for thyroid peroxidase and thyroglobulin were measured just before the first ovarian stimulation. Clinical pregnancy rate (PR), ongoing PR, and miscarriage rate were analyzed according to thyroid autoimmunity and serum TSH levels. The primary outcome was ongoing PR beyond 12 weeks of gestation.

RESULTS

The ongoing PR and miscarriage rates were similar between women with positive (n = 29) and negative autoantibodies (n = 186). In women with subclinical hypothyroidism (serum TSH ≥4.2 μIU/mL), ongoing PR was significantly lower than euthyroid women (22.2%, vs. 44.7%, p = 0.045), but miscarriage rate was similar. The group with serum TSH ≥3.4 μIU/mL showed a significantly lower ongoing PR (23.9% vs. 46.7%, p = 0.005) and significantly higher miscarriage rate (38.9% vs. 14.1%, p = 0.020). In multivariate logistic regression analysis, serum TSH ≥3.4 μIU/mL was an independent unfavorable predictor for ongoing PR (odds ratio 0.375, p = 0.013).

CONCLUSION

Thyroid autoantibodies did not affect clinical IVF outcomes, but women with serum TSH ≥3.4 μIU/mL demonstrated poor IVF outcomes.

The impact of levothyroxine therapy on pregnancy and neonatal outcomes in euthyroid pregnant women with thyroid autoimmunity: A systematic review, meta-analysis and trial sequential analysis

Background: At present, only one systematic review has investigated the effect of levothyroxine (LT4) in the treatment of euthyroid pregnant women with thyroid autoimmunity, but some problems [such as merging different types of research for meta-analysis, lacking neonatal outcomes, and so on] exist in this study, satisfactory results can not be provided. So, this systematic review was performed to investigate the effect of LT4 in euthyroid pregnant women with thyroid autoimmunity, in the hope of providing more comprehensive evidence for clinical use. Methods: Medline (Ovid), Embase (Ovid), and Cochrane Central Register of Controlled Trials were electronically searched from database inception to March 2022. We included cohort studies and RCTs that evaluated the impact of LT4 therapy on pregnancy and neonatal outcomes in euthyroid pregnant women with thyroid autoimmunity. Meta-analyses of different types of studies were performed separately, and meta-analyses were further performed by only including researches with low and moderate risk of bias. We used the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach to evaluate the quality of evidence, and used TSA to test the sufficiency of the evidence. Results: Finally, 2,901 euthyroid pregnant women with thyroid autoimmunity in six RCTs and five cohort studies were included. In all outcomes, no statistically significant differences were found between LT4 group and control group, including miscarriage [RR = 0.85, 95%CI (0.69,1.05), p = 0.14, I ² = 1%], preterm birth [RR = 0.80, 95%CI (0.59,1.08), p = 0.14, I2 = 0%], preeclampsia [RR = 0.68, 95%CI (0.12, 3.91), p = 0.66, I ² = 0%], placenta abruption [Peto' OR = 0.14, 95%CI (0.00, 6.94), p = 0.32, I ² = 0%], birth weight [MD = -36.00, 95%CI (-170.41, 98.41), p = 0.60, I ² = 0%], gestational age at delivery [MD = -0.10, 95%CI (-0.61, 0.41), p = 0.70, I ² = 0%] and neonatal admission [RR = 1.33, 95%CI (0.21, 8.58), p = 0.76, I ² = 0%]. The results for all outcomes were insufficient and inconclusive as demonstrated by TSA. The GRADE assessments showed that the quality of evidence of 4 outcomes (miscarriage, preterm birth, birth weight and gestational age at delivery) were moderate, and 3 outcomes (preeclampsia, placenta abruption and neonatal admission) were low or very low. Conclusion: For pregnancy and neonatal outcomes in euthyroid pregnant women with thyroid autoimmunity, we did not find benefit of LT4 treatment in this study. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022346745, identifier CRD42022346745.

A Questionnaire Survey of German Thyroidologists on the Use of Thyroid Hormones in Hypothyroid and Euthyroid Patients: The THESIS (Treatment of Hypothyroidism in Europe by Specialists: An International Survey) Collaborative

OBJECTIVE

To identify the attitudes of German thyroid specialists towards the clinical treatment of hypothyroidism using thyroid hormones (TH).

METHODS

All members of the thyroid section of the German Endocrine Society (DGE) were e-mailed an invitation to participate in a web-based survey about substitution with TH.

RESULTS

Out of 206 members of the DGE's thyroid section, 163 (79.1%) responses were received and included in the analysis. Of responding members, 98.6% used levothyroxine (LT4) as the treatment of choice, and 45.4% also prescribed combination therapy with liothyronine (LT4+LT3) in their clinical practice (p<0.001). LT4+LT3 combination was favored in patients with persistent hypothyroidism symptoms despite biochemical euthyroidism on LT4 treatment (p<0.001). Of all respondents, 26.4% never indicated TH therapy for euthyroid patients (p<0.001), while the remainder would consider THs for one or more indications (62.9% for euthyroid infertile women with high anti-thyroid antibody levels (p<0.001), 7.1% in patients with severe hypercholesterolemia, as complementary treatment (p=0.007), and 57.1% in patients with simple goiter (p<0.001)). In conditions that could interfere with LT4 absorption, most respondents still preferred tablets and did not expect a significant difference when switching from one LT4 formulation to another.

CONCLUSION

For German thyroid specialists, LT4 is the treatment of choice for hypothyroidism. Combination therapy with LT4+LT3 was considered for patients with persistent symptoms. Even in conditions that could affect bioavailability, German thyroid specialists prefer LT4 tablets rather than other LT4 formulations, such as liquid or soft-gel capsules. The widespread use of thyroid hormone for non-hypothyroid conditions is not consistent with current evidence and needs further study.

A Predictive Role of Autoantibodies Against the Epitope aa168–183 of ENO1 in the Occurrence of Miscarriage Related to Thyroid Autoimmunity

Objective

The aim of the research is to study the association between the serum levels of autoantibodies against one important epitope (¹⁶⁸FMILPVGAANFREAMR¹⁸³, designated as P6) of α-enolase (ENO1-P6Abs) and miscarriage among euthyroid females with thyroid autoimmunity (TAI).

Methods

Anti-ENO1-P6 total IgG was investigated in 432 euthyroid women, and its four subclasses were analyzed in 184 euthyroid women. The serum FT4, TSH, TgAb, and TPOAb levels were determined using an electrochemiluminescence immunoassay. The serum ENO1-P6Ab and anti-protein disulfide isomerase A3 autoantibody (PDIA3Ab) levels were determined using an enzyme-linked immunosorbent assay.

Results

The serum levels of anti-ENO1-P6 total IgG, IgG2, IgG3, and IgG4 were significantly higher in euthyroid TAI females than in non-TAI controls. Additionally, anti-ENO1-P6 total IgG and its 4 subtypes were all markedly higher in euthyroid TAI females with pregnancy loss than those without miscarriage. Moreover, logistic regression analysis showed that highly expressed anti-ENO1-P6 total IgG, IgG1, IgG2, and IgG3 subtypes in the serum were all independent risk factors for euthyroid TAI-related miscarriage, and its IgG1 was also for non-TAI-related abortion. According to the trend test, the prevalence of miscarriage was increased in a titer-dependent manner with the raised levels of serum anti-ENO1-P6 total IgG and IgG1, IgG2, and IgG3 subtypes among euthyroid TAI females. The receiver operating characteristic curve analysis of anti-ENO1-P6 total IgG and IgG1, IgG2, and IgG3 subclass expressions in the serum for miscarriage prediction in euthyroid TAI females exhibited that the total areas under the curves were 0.773 ± 0.041, 0.761 ± 0.053, 0.827 ± 0.043, and 0.760 ± 0.050, respectively (all P <0.0001). Their corresponding optimal cut-off OD450 values were 0.68 (total IgG), 0.26 (IgG1), 0.97 (IgG2), and 0.48 (IgG3), with sensitivities of 70.8, 87.5, 83.3, and 85.4%, and specificities of 70.8, 59.1, 77.3, and 56.8%, respectively. There was an additive interaction between serum anti-ENO1-P6 and anti-PDIA3 total IgGs on the development of miscarriage (RERI = 23.6, AP = 0.79, SI = 5.37).

Conclusion

The highly expressed ENO1-P6Abs may be important risk factors for euthyroid TAI-related miscarriage. The serum levels of ENO1-P6Abs may become good predictive markers for pregnancy loss in euthyroid TAI females, especially its IgG2 subclass expression.

IVF/ICSI outcomes of euthyroid infertile women with thyroid autoimmunity: does treatment with aspirin plus prednisone matter?

Background

Thyroid autoimmunity (TAI) has been demonstrated to be associated with adverse pregnancy including recurrent miscarriage, unexplained infertility, and implantation failure. To settle with the fertility problem, prescribing aspirin combined with prednisone (P + A) to women positive for anti-thyroid antibodies is frequent in clinical practice, but the underlying effect remains controversial.

Methods

A multicenter, retrospective study was conducted in three reproductive centers from 2017 to 2020. A total of 494 euthyroid infertile women were recruited who were positive for anti-thyroperoxidase and/or thyroglobulin antibodies (TPOAb and TgAb, respectively) with thyroid-stimulating hormone (TSH) levels ranging 0.35-4.0mIU/L and underwent their first in vitro fertilization and embryo transfer (IVF-ET) cycle. Ultimately, 346 women were included of which 150 women were treated with prednisone (10 mg/d) and aspirin (100 mg/d). The remaining 196 women were untreated (control group). Treatment started on the day of embryo transfer and continued until clinical pregnancy was determined.

Results

The clinical pregnancy rate was 57.5% vs. 63.5% in the control and treated groups (P = 0.414) for first fresh embryo transfer cycles and 57.8% vs. 61.8% for frozen-thawed embryo transfer cycles (P = 0.606). In addition, the live birth rate for the fresh embryo transfer was 49.6% vs. 47.3% in the control and treated groups (P = 0.762). Logistic regression revealed that aspirin plus prednisone did not improve the clinical pregnancy rate or miscarriage rate. Furthermore, it was observed that low free triiodothyronine (FT3) was associated with high miscarriage rates.

Conclusions

Utilizing an adjuvant treatment of P + A after the embryo transfer may not be necessary in euthyroid women with thyroid autoimmunity undergoing their first IVF-ET, regardless of the embryo type (fresh or frozen).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04532-2.

Use of thyroid hormones in hypothyroid and euthyroid patients: a 2020 THESIS questionnaire survey of members of the Hellenic Endocrine Society

PURPOSE

To investigate current practices of specialists in the use of thyroid hormone preparations in Greece as part of an ongoing international survey, namely THESIS-Treatment of Hypothyroidism in Europe by Specialists: an International Survey.

METHODS

An electronic link leading to an anonymized questionnaire was sent to all (n = 837) members of the Hellenic Endocrine Society.

RESULTS

In total, 501 respondents participated in the survey, though only part of the questionnaire was filled in by some participants. A total of 88.2% were endocrinologists and 57.9% worked in private practice. Levothyroxine (LT4) was the first-line choice (98.6%) for the treatment of hypothyroid patients. In total, 70.2% preferred LT4 soft-gel capsules for patients reporting intolerance to various foods. Soft-gel capsules were the preferred LT4 formulation for patients on generic LT4 and with unexplained poor biochemical control of hypothyroidism (66.3%) or inability to take LT4 fasted and separate from food/drink (68.3%). It was found that 48.4% would never use combined LT4 + LT3. However, 25% would use combination therapy for a short period in patients recovering from protracted hypothyroidism or in patients with normal serum TSH but persistent symptoms. Concerning euthyroid individuals, 31.9% considered treatment with thyroid hormones in infertile females with positive thyroid antibodies and 24.4% in patients with growing goiter. Selenium or iodine supplementation was used occasionally, mostly in patients with coexisting autoimmune thyroiditis.

CONCLUSIONS

LT4 tablets are the treatment of choice for hypothyroidism in Greece. Several conditions may lead to various other practices, some of which deviate from current evidence-based guidelines and need more scrutiny.

Thyroid autoimmunity and its negative impact on female fertility and maternal pregnancy outcomes

Thyroid autoimmunity (TAI) is commonly defined as the presence of thyroperoxidase antibodies (TPOAbs) and/or thyroglobulin antibodies (TgAbs), which predisposes an individual to hypothyroidism. TAI affects nearly 10% of women of reproductive age and evokes great interest from clinicians because of its potentially negative impact on female fertility and pregnancy course. In this mini-review, we review the current literature concerning the influence of TPOAb or TPOAb/TgAb positivity without thyroid dysfunction on reproduction. TAI may negatively affect female fertility; several studies have found an increased prevalence of TAI in infertile women, especially in those with unexplained infertility and polycystic ovary syndrome. According to some observations, TAI might also be connected with premature ovarian insufficiency and endometriosis. The relationship between TAI and an increased risk of pregnancy loss is well documented. The pathophysiological background of these observations remains unclear, and researchers hypothesize on the direct infiltration of reproductive organs by thyroid antibodies, co-existence of TAI with other autoimmune diseases (either organ specific or systemic), immunological dysfunction leading to inhibition of immune tolerance, and relative thyroid hormone deficiency. Interestingly, in the current literature, better outcomes of assisted reproductive technology in women with TAI have been reported compared with those reported in earlier publications. One plausible explanation is the more widespread use of the intracytoplasmic sperm injection method. The results of randomized clinical trials have shown that levothyroxine supplementation is ineffective in preventing adverse pregnancy outcomes in women with TAI, and future research should probably be directed toward immunotherapy.

Effect of Levothyroxine on Pregnancy Outcomes in Pregnant Women With Hypothyroxinemia: An Interventional Study

CONTEXT

Adverse maternal outcomes and perinatal complications are associated with maternal hypothyroidism. However, the utility of levothyroxine (L-T4) in the treatment of pregnant women with hypothyroxinemia is unclear.

OBJECTIVE

This study aimed to evaluate the effects of L-T4 on maternal and perinatal outcomes in pregnant women with hypothyroxinemia.

METHODS

The nonrandomized interventional study was conducted at Shanghai First Maternity and Infant Hospital, Punan Hospital of Shanghai, and Beicai Community Health Center of Shanghai. The pregnant women with hypothyroxinemia from the first trimester were enrolled and divided into treatment and control groups. 463 taking L-T4 and 501 not administering L-T4 were analyzed in the study. All participants were screened for TPOAB/TGAB antibody status.

MAIN OUTCOME

The primary outcome of the study was the hypertensive disorder of pregnancy (HDP), measured as the proportion of HDP. In addition to this primary outcome, some secondary outcomes will be measured: miscarriage, gestational diabetes mellitus, premature rupture of membranes, placental abruption, intrahepatic cholestasis of pregnancy, fetal distress, macrosomia, and neonates admitted to the neonatal intensive care unit (NICU). The effects of L-T4 on the incidence of adverse pregnancy outcomes and perinatal complications were compared.

RESULTS

Multivariate logistic regression analysis showed that L-T4 treatment (adjusted odds ratio = 1.78 [95% CI = 1.00-3.16], p = 0.04) significantly reduced the incidence of miscarriage. Otherwise, lower neonates admitted to the NICU were strongly associated with the L-T4 group (adjusted odds ratio = 1.36 [95% CI = 1.01 - 1.83], p = 0.04). There were no significant differences in the incidence rates of other adverse maternal outcomes and perinatal complications between pregnant women with hypothyroxinemia receiving and those not receiving L-T4 treatment.

CONCLUSION

The incidence of HDP was not significantly reduced using L-T4 in pregnant women with hypothyroxinemia. The results of this study also showed that L-T4 treatment significantly reduced the miscarriages rate and the proportion of newborns admitted to the NICU.

Use of thyroid hormones in hypothyroid and euthyroid patients: A 2020 THESIS questionnaire survey of members of the Danish Endocrine Society

PURPOSE

The standard treatment of hypothyroidism is levothyroxine (LT4), which is available as tablets or soft-gel capsules in Denmark. This study aimed to investigate Danish endocrinologists' use of thyroid hormones in hypothyroid and euthyroid patients.

METHODS

An e-mail with an invitation to participate in an online survey investigating practices about substitution with thyroid hormones was sent to all members of the Danish Endocrine Society (DES).

RESULTS

Out of 488 eligible DES members, a total of 152 (31.2%) respondents were included in the analysis. The majority (94.1%) of responding DES members use LT4 as the treatment of choice. Other treatment options for hypothyroidism are also used, as 58.6% prescribe combination therapy with liothyronine (LT3) + LT4 in their clinical practice. LT4 + LT3 combination is preferred in patients with persistent symptoms of hypothyroidism despite biochemical euthyroidism on LT4 treatment. Over half of the respondents answered that thyroid hormone therapy is never indicated for euthyroid patients, but 42.1% will consider it for euthyroid infertile women with high antibody levels. In various conditions that could interfere with the absorption of LT4, most responding Danish endocrinologists prefer tablets and do not expect a significant difference when switching from one type of tablet formulation to another.

CONCLUSION

The treatment of choice for hypothyroidism is LT4. Combination therapy with LT4 + LT3 is considered for patients with persistent symptoms. Even in the presence of conditions affecting bioavailability, responding Danish endocrinologists prefer LT4 tablets rather than newer LT4 formulations, such as soft-gel capsules.

Impact of levothyroxine in women with positive thyroid antibodies on pregnancy outcomes: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To evaluate the effect of levothyroxine therapy on pregnancy outcomes compared with placebo or no treatment in women without overt hypothyroidism with presence of thyroid peroxidase antibodies (TPOAb) and/or thyroglobulin antibodies (TgAb).

DESIGN

Systematic review and meta-analysis of randomised controlled trials STUDY ELIGIBILITY CRITERIA: Prespecified criteria for inclusion were: randomised trials of levothyroxine versus control (placebo or no treatment) among women with positive TPOAb or TgAb who were pregnant or considering conception.

DATA SOURCES

Ovid MEDLINE, EMBASE, CINAHL, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials were searched from 1980 to 5 November 2020.

OUTCOME MEASURES

Prespecified data elements were extracted and where appropriate, meta-analyses were conducted. Main outcomes include pregnancy achieved, miscarriage, preterm delivery and live birth.

RISK OF BIAS ASSESSMENT

Cochrane Risk of Bias Tool for Quality Assessment of Randomised Controlled Trials.

RESULTS

From 3023 citations, 79 citations were identified for full-text review. Of these, six trials (total of 2263 women) were included for qualitative and quantitative analyses. Risk of bias was deemed low for only one trial. There was no significant difference in the relative risk (RR) of pregnancy achieved (RR 1.03; 95% CI 0.93 to 1.13), miscarriage (RR 0.93; 95% CI 0.76 to 1.14), preterm delivery (RR 0.66; 95% CI 0.39 to 1.10) or live births (RR 1.01; 95% CI 0.89 to 1.16) in thyroid autoimmune women treated with levothyroxine compared with controls. Sensitivity analyses of preterm birth identified study quality and timing of levothyroxine initiation as sources of heterogeneity.

CONCLUSIONS

Among pregnant women or women planning conception, with thyroid autoimmunity, there is a lack of evidence of benefit for levothyroxine use (moderate to high Grading of Recommendations, Assessment, Development and Evaluations). Recommendations to use levothyroxine in this setting need to be reconsidered.

PROSPERO REGISTRATION NUMBER

CRD42019130459.

Use of Thyroid Hormones in Hypothyroid and Euthyroid Patients: A 2020 THESIS Questionnaire Survey of Members of the Swedish Endocrine Society

BACKGROUND

The standard treatment of hypothyroidism is levothyroxine (LT-4). However, there are several controversies regarding treatment of hypothyroid patients.

AIM

To investigate the Swedish endocrinologists' use of thyroid hormones in hypothyroid and euthyroid individuals.

METHODS

Physician members of the Swedish Endocrine Society (SEF) were invited by e-mail to participate in an online survey investigating this topic.

RESULTS

Out of the eligible 411 members, 116 (28.2%) responded. The majority (98.9%) stated that L-T4 is the treatment of choice. However, around 50% also prescribed liothyronine (L-T3) or a combination of L-T4+L-T3 in their practice. Combination therapy was mostly (78.5%) used in patients with persistent hypothyroid symptoms despite biochemical euthyroidism on L-T4 treatment. Most respondents prescribed L-T4 tablets and did not expect any major changes with alternative formulations such as soft-gel capsules or liquid formulations in situations influencing the bioavailability of L-T4. In euthyroid patients, 49.5% replied that treatment with thyroid hormones was never indicated, while 47.3% would consider L-T4 for euthyroid infertile women with high thyroid peroxidase (TPO) antibody levels.

CONCLUSION

The treatment of choice for hypothyroidism in Sweden is L-T4 tablets. Combination therapy with L-T4+L-T3 tablets was considered for patients with persistent symptoms despite biochemical euthyroidism. Soft-gel capsules and liquid solutions of L-T4 were infrequently prescribed. Swedish endocrinologists' deviation from endocrine society guidelines merits further study.