Relationship between anti-thyroid peroxidase antibody positivity and pregnancy-related and fetal outcomes in Euthyroid women: a single-center cohort study

Subclinical hypothyroidism in the infertile female population: a guideline

There is controversy regarding whether to treat subtle abnormalities of thyroid function in infertile female patients. This guideline document reviews the risks and benefits of treating subclinical hypothyroidism in female patients with a history of infertility and miscarriage, as well as obstetric and neonatal outcomes in this population.

Maternal isolated hypothyroxinemia in the first trimester is not associated with adverse pregnancy outcomes, except for macrosomia: a prospective cohort study in China

Objective

Insufficient thyroid hormone levels during pregnancy, especially in the first trimester, adversely affect maternal and fetal health. However, the impact of isolated hypothyroxinemia (IH) on adverse pregnancy outcomes remains controversial. Therefore, this study aimed to investigate the association between IH during the first trimester and adverse pregnancy outcomes.

Methods

This prospective cohort study included 1236 pregnant women. Thyroid-stimulating hormone and free thyroxine levels were measured before 13 weeks of gestation. Logistic regression analysis and the Cochran-Armitage trend test were used to assess the association between IH in the first trimester and adverse pregnancy outcomes.

Results

IH during the first trimester was associated with an increased risk of macrosomia. After adjusting for confounding factors, including age, body mass index, parity, abnormal pregnancy history, fasting blood glucose, and total cholesterol, multivariate logistic regression analysis showed that IH in the first trimester remained an independent risk factor for macrosomia. In addition, the risk of macrosomia increased with IH severity. However, no significant relationship was found between IH during the first trimester and gestational diabetes mellitus, hypertensive disorders of pregnancy, spontaneous abortion, premature rupture of membranes, placental abruption, oligohydramnios, premature delivery, fetal distress, or low birth weight.

Conclusion

IH during the first trimester did not increase the risk of adverse pregnancy outcomes, except for macrosomia.

Gestation-suppressed serum TSH levels during early pregnancy are not associated with altered maternal and neonatal outcomes

Objective

The aim of the study was to investigate the impact of suppressed serum TSH levels (sTSH) during early pregnancy on maternal and neonatal outcomes.

Methods

In this single-centre, retrospective cohort study 1081 women were screened at 11.8 ± 2.4 weeks of pregnancy for TSH, free T4 (FT4) and TPOAb. Exclusion criteria were twin- and assisted- reproduction pregnancies, women with TSH levels >3.74 mIU/L, severe hyperthyroidism, treated for thyroid dysfunction before or after screening and gestational blood sampling <6 or >16 weeks of pregnancy. The prevalence of adverse pregnancy outcomes was compared between the study group sTSH (TSH: < 0.06 mIU/L; n = 36) and euthyroid controls (TSH: 0.06-3.74 mIU/L; n = 1045), and the impact of sTSH on pregnancy outcomes verified in logistic regression analyses.

Results

Median (IQR) serum TSH level in women with sTSH was 0.03 (0.03-0.03) vs 1.25 (0.81-1.82) mIU/L in controls and FT4 levels 18.0 (14.4-20.3) vs 14.2 (12.9-15.4) pmol/L; both P < 0.001. None of the women with sTSH had thyrotropin receptor antibodies. Compared with controls, the prevalence of TPOAb positivity (TAI) was comparable between groups (5.6% vs 6.6%; P = 0.803). The prevalence of maternal and neonatal pregnancy outcomes was comparable between the study and control group. The logistic regression analyses with corrections for TAI, FT4 and demographic parameters confirmed the absence of an association between sTSH, and the following outcomes: iron deficient anaemia (aORs (95% CI)): 1.41 (0.64-2.99); P = 0.385, gestational diabetes: 1.19 (0.44-2.88); P = 0.713, preterm birth: 1.57 (0.23-6.22);P = 0.574 and low Apgar-1' score: 0.71 (0.11-2.67); P = 0.657.

Conclusions

Suppressed serum TSH levels during the first to early second trimester of pregnancy were not associated with altered maternal or neonatal outcomes.

Maternal thyroid peroxidase antibody positivity and its association with incidence of low birth weight in infants

Background

Autoimmune thyroid disease is a prevalent condition affecting women of reproductive age, leading to thyroid dysfunction and impacting pregnancy outcomes. While the critical role of thyroid hormone in pregnancy outcomes is well-established, the potential association between positive anti-thyroid peroxidase antibodies (TPOAb) and adverse pregnancy outcomes in pregnant women with normal thyroid function remains unclear.

Objective

This study aims to investigate the relationship between maternal TPOAb positivity and adverse pregnancy outcomes with normal thyroid function.

Methods

We collected baseline information from pregnant women who visited our hospital between February 2009 and June 2012. Blood samples were taken to measure thyroid stimulating hormone (TSH), free thyroxine (FT4), TPOAb, and anti-thyroglobulin antibodies (TGAb). The incidence of adverse pregnancy outcomes was compared between TPOAb-positive and TPOAb-negative groups among participants with normal thyroid function.

Results

A total of 7,046 pregnant women with normal thyroid function were included, comprising 6,700 with negative TPOAb and 346 with positive TPOAb. The TPOAb-positive group exhibited a higher age (26.0 vs. 27.0 years, p = 0.02) and greater serum TSH levels (1.72 vs. 1.94 mIU/L, p = 0.029), while the gestational week of blood collection was lower (31.9 vs. 26.5 weeks, p = 0.001). Univariate analysis revealed a higher incidence of low birth weight (LBW) in offspring of TPOAb-positive women compared to the TPOAb-negative group (3.5% vs. 1.9%, p = 0.035). After adjusting for confounding factors such as age, gestational week of blood collection, menstrual history, education level, gestational diabetes, gestational hypertension, TGAb, TSH, and FT4, TPOAb positivity emerged as an independent risk factor for LBW infants (OR: 2.317, 95% CI: 1.057-5.076, p = 0.036), while other adverse pregnancy outcomes did not show a significant correlation with TPOAb positivity.

Conclusion

Our findings suggest that TPOAb-positive pregnant women with normal thyroid function are more likely to deliver LBW infants. Regular monitoring of TPOAb-positive pregnancies and timely interventions throughout all stages of pregnancy are crucial.

Thyroid Peroxidase Antibodies in Infertile Women with Polycystic Ovary Syndrome

To compare the rate of positive thyroid peroxidase antibodies (TPO Ab) between women with different polycystic ovary syndrome (PCOS) phenotypes and women without PCOS. This is a retrospective cohort study. Women with PCOS at My Duc Hospital between June 1, 2020, and March 27, 2021, were matched with non-PCOS women by age. TPO Ab (cut-off: 34 IU/mL) and thyroid-stimulating hormone (TSH) levels were measured as markers of Hashimoto thyroiditis and thyroid function, respectively. One thousand eight hundred eight infertile women were included, 904 with PCOS (mean age 29.0 ± 3.58 years) and 904 without PCOS (29.1 ± 3.4 years; controls). Women with PCOS had a higher body mass index (22.8 ± 3.84 vs. 19.9 ± 2.23 kg/m2, p < 0.001), but most were not overweight/obese. Rates of positive TPO Ab in women with versus without PCOS were 8.2% and 8.4%, respectively (p = 0.932). Rates of positive TPO Ab in patients with PCOS phenotype A, B, C, or D were not statistically different (7.5%, 2.9%, 20.0%, and 7.8%, respectively). Median TSH concentrations were similar in the PCOS and control groups (1.84 mIU/L vs. 1.78 mIU/L, respectively; p = 0.194). Based on a linear regression model, there was no correlation between either BMI or the estradiol to progesterone ratio and TPO Ab status. In a large population of infertile women with PCOS who were mostly lean patients, rates of positive TPO Ab across all four PCOS phenotypes did not differ significantly from those in women without PCOS. These findings did not support the hypothesis that PCOS is a risk factor for Hashimoto thyroiditis.

Maternal preconception thyroid autoimmunity is associated with neonatal birth weight conceived by PCOS women undergoing their first in vitro fertilization/intracytoplasmic sperm injection

BACKGROUND

Thyroid autoimmunity and polycystic ovary syndrome (PCOS) are the most common endocrinopathies and have close relationships based on common etiology and pathogenesis, including genetic susceptibility, metabolic disorders, hormonal dysregulation, immune response, and inflammatory activation. The co-occurrence of both diseases is associated with adverse reproductive outcomes, but its effect on neonatal outcomes remains largely unknown. We aim to explore the effect of thyroid autoimmunity on neonatal birth weight in PCOS women undergoing IVF/ICSI.

METHODS

This is a retrospective analysis of 486 PCOS women who underwent the first IVF/ICSI cycles and gave birth to 361 singletons and 125 twins during 2018 - 2020 at a reproductive center. The associations between maternal preconception serum thyroid function and autoimmunity indicators and birth weights of the singleton and twin groups were evaluated using generalized linear models (GLMs) and generalized estimate equations (GEEs), respectively. Analyses were further stratified by neonatal sex, maternal age, and maternal preconception BMI to assess the possible interaction effects.

RESULTS

Maternal preconception serum TPOAb had a significant negative association with singleton birth weight (P for trends = 0.03). Compared with women in the first tertile of TPOAb, women in the third tertile had a change in singleton birth weight of - 119.72 g (95% CI: - 222.68 g, - 16.70 g). Maternal preconception serum TPOAb had a significant positive association with twin birth weight (P for trends = 0.01). Compared with women in the first tertile of TPOAb, women in the third tertile had a change in twin birth weight of 138.62 g (95% CI: 33.96 g, 243.30 g). Besides, maternal preconception serum TPOAb had a specific association with increased twin birth weight for female neonates, a specific association with decreased singleton birth weight for PCOS women under 35 years, and a specific association with decreased twin birth weight for overweight PCOS women (all P for interactions < 0.05).

CONCLUSIONS

Maternal preconception thyroid autoimmunity may affect the birth weights of both singleton and twin neonates. Further large cohorts and experimental studies are required to confirm these findings and explore the underlying mechanisms.

Hydroxychloroquine improves pregnancy outcomes in patients undergoing frozen embryo transfer with positive serum autoantibodies

PROBLEM

Does hydroxychloroquine (HCQ) improve pregnancy outcomes after frozen embryo transfer (FET) cycles in patients who are positive for autoantibodies？ METHOD OF STUDY: This was a retrospective clinical study involving 128 patients who were positive for autoantibodies undergoing FET cycles between October 2017 and December 2022. Subjects were divided into two groups: a study group of 65 cycles with HCQ (HCQ was administered orally over 2 months before transplantation and continued during the first trimester) and a control group consisting of 63 cycles without HCQ (no HCQ was used throughout the FET cycle). Each patient was enrolled in the cohort only once. Then, we analyzed the clinical pregnancy outcomes between the two groups.

RESULTS

Analysis showed that HCQ was a factor that independently associated with clinical pregnancy rate (CPR) OR (Odds Ratio): 3.106; 95% confidence interval (CI): 1.458-6.616; p = .003. Furthermore, the implantation rate (IR), CPR and ongoing pregnancy rate (OPR) of the treatment group were significantly higher than those in the control group. The biochemical pregnancy rate (BPR) and early miscarriage rate (EMR) were significantly lower than that in the control group (p = .029, p < .001).

CONCLUSION

We found that HCQ improved clinical pregnancy outcomes and reduced the rate of first-trimester abortion in patients who were positive for autoantibodies during FET cycles.

The Thyroid Hormone Axis and Female Reproduction

Thyroid function affects multiple sites of the female hypothalamic-pituitary gonadal (HPG) axis. Disruption of thyroid function has been linked to reproductive dysfunction in women and is associated with menstrual irregularity, infertility, poor pregnancy outcomes, and gynecological conditions such as premature ovarian insufficiency and polycystic ovarian syndrome. Thus, the complex molecular interplay between hormones involved in thyroid and reproductive functions is further compounded by the association of certain common autoimmune states with disorders of the thyroid and the HPG axes. Furthermore, in prepartum and intrapartum states, even relatively minor disruptions have been shown to adversely impact maternal and fetal outcomes, with some differences of opinion in the management of these conditions. In this review, we provide readers with a foundational understanding of the physiology and pathophysiology of thyroid hormone interactions with the female HPG axis. We also share clinical insights into the management of thyroid dysfunction in reproductive-aged women.

First trimester sCD40L levels associated with adverse neonatal outcomes in euthyroid pregnant women with positive TPOAb

Backgrounds

It remained unclear whether isolated positive thyroid peroxidative antibodies (TPOAb) were associated with adverse maternal and neonatal outcomes. The purpose of this study was to observe adverse neonatal outcomes among euthyroid pregnant women with positive TPOAb and to investigate the underlying risk factors.

Methods

Euthyroid pregnant women with TPOAb positivity were enrolled and followed up in our study. Adverse neonatal outcomes such as preterm birth, low birth weight, and fetal macrosomia were observed. Clinical data in the first trimester were collected and compared between groups with or without adverse neonatal outcomes. Maternal serum soluble CD40 ligand (sCD40L) was also measured at the same time.

Results

A total of 176 euthyroid pregnant women with TPOAb positivity were finally enrolled and analyzed in our study. Thirty-nine (22.16%) euthyroid women with TPOAb positivity were found to have adverse neonatal outcomes. Thirteen participants received assisted reproductive technology (ART) in our study, and seven participants were in the adverse neonatal outcome group. Preterm birth, low birth weight, and fetal macrosomia were the most common comorbidities. The proportion of receiving ART and the levels of sCD40L and platelet were significantly higher in the adverse neonatal outcome group (all P < 0.05). Multivariate regression analysis showed that sCD40L and receiving ART were the independent risk factors for adverse neonatal outcomes. The odds ratio values of sCD40L higher than 5.625 ng/ml were 2.386 [95% confidence interval (CI) = 1.017 to 5.595; P = 0.046] for overall adverse neonatal outcome, 3.900 (95% CI = 1.194 to 12.738; P = 0.024) for preterm birth, and 3.149 (95% CI = 0.982 to 10.101; P = 0.054) for low birth weight.

Conclusions

Approximately one of the four euthyroid women with TPOAb positivity might have adverse neonatal outcomes. Measurement of sCD40L in first trimester might have a predictive value for adverse neonatal outcomes in euthyroid pregnant women with positive TPOAb.

The association between hypothyroidism and perinatal outcomes in patients with polycystic ovary syndrome

PURPOSE

To compare pregnancy, delivery, and neonatal outcomes in patients with polycystic ovary syndrome (PCOS) with and without concomitant hypothyroidism.

METHODS

A retrospective population-based cohort study including all women with an ICD-9 diagnosis of PCOS in the US between 2004 and 2014, who delivered in the third trimester or had a maternal death. We compared women with a concomitant diagnosis of hypothyroidism to those without. Women with hyperthyroidism were excluded. Pregnancy, delivery, and neonatal outcomes were compared between the two groups.

RESULTS

Overall, 14,882 women met inclusion criteria. Among them, 1882 (12.65%) had a concomitant diagnosis of hypothyroidism, and 13,000 (87.35%) did not. Women with concomitant hypothyroidism, compared to those without, were characterized by increased maternal age (25.5% ≥ 35 years vs. 18%, p < 0.001, respectively), and had a higher rate of multiple gestations (7.1% vs. 5.7%, p = 0.023). Interestingly, pregnancy, delivery and neonatal outcomes were comparable between the groups, except for a higher rate of small-for-gestational-age (SGA) neonates in the group with hypothyroidism (4.1% vs. 3.2%, p = 0.033) (Tables 2 and 3). In a multivariate logistic regression adjusting for potential confounders, hypothyroidism was no longer found to be associated with SGA (adjusted odds ratio [aOR] 1.32, 95% confidence interval [CI] 0.99-1.75, p = 0.057), but was found to increase the odds for preeclampsia (aOR 1.30, 95% CI 1.06-1.59, p = 0.012).

CONCLUSIONS

In patients with PCOS, concomitant hypothyroidism significantly increases the risk for preeclampsia. Unexpectedly, other pregnancy complications commonly increased by hypothyroidism were not increased in women with PCOS, likely due to the inherent elevated baseline pregnancy risks of PCOS.

Prediction of preterm delivery based on thyroid peroxidase antibody levels and other identified risk factors

OBJECTIVE

Thyroid dysfunction and TPOAb positivity during pregnancy are associated with adverse pregnancy outcomes such as preterm delivery. The aim of this study was to predict preterm delivery based on identified risk factors, especially TPOAb levels.

STUDY DESIGN

A secondary analysis was run on data collected in the Tehran Thyroid and Pregnancy study (TTPs). We used the data of 1515 pregnant women with singletons. The association between risk factors and preterm birth (delivery before 37 completed weeks of gestation) was investigated in univariate analysis. Multivariate logistic regression analysis was performed to identify independent risk factors, and a stepwise backward elimination method was used to determine the helpful combination of risk factors. The nomogram was developed based on a multivariate logistic regression model. The performance of the nomogram was evaluated using a concordance index and calibration plots with bootstrap samples. Statistical analysis was performed using STATA software package; the significance level was set at P < 0.05.

RESULTS

Based on multivariate logistic regression analysis, a combination of previous preterm delivery [OR: 5.25; 95 %CI: (2.13-12.90), p < 0.01], TPOAb [OR: 1.01; 95 %CI: (1.01-1.02), and T4 [OR: 0.90; 95 %CI: (0.83-0.97); p = 0.04] as independent risk factors that most precisely predicted preterm birth. The area under the curve (AUC) was 0.66 (95% CI: 0.61-0.72). The calibration plot suggests that the fit of the nomogram is reasonable.

CONCLUSION

A combination of T4, TPOAb, and previous preterm delivery was identified as independent risk factors that accurately predicted preterm delivery. The total score obtained based on the nomogram designed based on risk factors can predict the risk of preterm delivery.

Thyroid autoimmunity and pregnancy in euthyroid women

Women with thyroid autoimmunity (TAI), predominately characterized by increased levels of thyroid peroxidase antibody (TPOAb), are at risk for developing pregnancy related complications. In this review, we discuss the importance of TAI during natal and perinatal stages. Before pregnancy, TAI is associated with higher mean serum TSH levels and certain causes of subfertility. During pregnancy, TAI increases the risk of an insufficient response of the thyroid to an increasing strain induced by pregnancy, and consequently (subclinical) hypothyroidism might develop. Euthyroid women with TAI have a higher rate of maternal and foetal complications, but it seems that causality cannot be pinned down to thyroid dysfunction alone. Almost half of the women known with TAI prior to pregnancy will also develop post-partum thyroiditis (PPT). However, any relation between PPT and post-partum depression remains uncertain. More research is required to explain possible associations between TAI and pregnancy morbidities, and studies should focus on a better understanding of TAI as such. Given the many unanswered questions, at present, it is not recommended to screen all (potentially) pregnant women for the presence of TAI.

Effects of Levothyroxine Therapy on Pregnancy and Neonatal Outcomes in Subclinical Hypothyroidism

Purpose

To assess the effects of levothyroxine (LT4) therapy on pregnancy and neonatal outcomes in pregnant women with subclinical hypothyroidism (SCH) who had different thyroid peroxidase antibody (TPOAb) status.

Methods

The data of pregnant women from the Chengdu Hospital of Integrated Traditional Chinese and Western Medicine between January 2017 and August 2019 were collected. SCH was defined as 11.88 < free thyroxine (FT4) < 20.06pmol/L in conjunction with thyroid-stimulating hormone (TSH) >4.00 mU/L. Some clinical characteristics have been collected, including body mass index (BMI) before pregnancy, number of pregnancies, number of miscarriages (spontaneous abortion), parity, family history of diabetes, history of smoking, history of drinking, TSH, FT4, and TPOAb levels. The prevalence of pregnancy and neonatal outcomes in the LT4 and non-LT4 groups, and in the LT4 and euthyroid control groups were compared, respectively. Univariate and multivariate logistic regression analyses were used to assess the effects of LT4 therapy on pregnancy and neonatal outcomes in SCH pregnant women with TPOAb.

Results

A total of 985 subjects were enrolled and divided into LT4 group with 478 patients, non-LT4 group with 156 patients and euthyroid control group with 351 patients. The prevalence of amniotic fluid abnormalities and premature delivery in the LT4 group was lower than that in the non-LT4 group in participants with TPOAb-positive (TPOAb⁺). After adjusting age, BMI prior to pregnancy, number of pregnancies, number of miscarriages, parity, TSH and FT4 level, the SCH pregnant women with TPOAb⁺ in the LT4 group had a lower risk of amniotic fluid abnormalities and premature delivery than that in the non-LT4 group.

Conclusion

LT4 therapy could reduce the risk of premature delivery and amniotic fluid abnormalities in the SCH pregnant women with TPOAb⁺. However, more randomized trials are required to confirm this association before the unequivocal advocacy of LT4 therapy in pregnant women with SCH.

Association Between Iodine Nutritional Status and Adverse Pregnancy Outcomes in Beijing, China: a Single-Center Cohort Study

Iodine is an essential trace element for humans and the main raw material for thyroid hormone synthesis. However, the association between iodine nutritional status and adverse pregnancy outcomes in different regions remains controversial. This single-center cohort study was focused on the association between iodine nutritional status and adverse pregnancy outcomes in Beijing, China. We enrolled 726 pregnant women who were registered at the Peking University International Hospital between February 2017 and December 2019. To analyze the association between iodine nutritional status variations and adverse pregnancy outcomes, this study cohort included 390 (53.72%) participants with iodine deficiency, 206 (28.37%) with an adequate iodine level, 103 (14.19%) with a more than adequate iodine level, and 27 (3.72%) with iodine excess, according to the urinary iodine (UI) status of pregnant women. After adjusting for age, body mass index, parity, and history of spontaneous abortion, we identified iodine deficiency as a risk factor for anti-thyroid peroxidase antibody (TPOAb) positivity [odds ratio (OR), 3.646; 95% confidence interval (95% CI), 1.658-8.017], anti-thyroglobulin antibody (TGAb) positivity (OR, 3.109; 95% CI, 1.465-6.599), and thyroid autoimmunity (OR, 2.885; 95% CI, 1.539-5.407). There was a non-linear relationship between UI and the concentrations of TPOAb and TGAb (P_non-linear < 0.05). Iodine deficiency during the first trimester is a risk factor for thyroid autoantibody positivity. The relationship between UI and the concentrations of TPOAb and TGAb follows a nearly U-shaped curve. Thus, physicians should critically consider the iodine nutritional status of pregnant women during the first trimester. Clinical Trials.gov Identifier: NCT02966405.

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.

Effects of Thyroperoxidase Antibody and Thyroglobulin Antibody on Maternal and Neonatal Outcomes in Pregnant Women

The aim of the study was to evaluate the effects of thyroperoxidase antibody (TPOAb) and thyroglobulin antibody (TgAb) on maternal and neonatal adverse outcomes in pregnant women. A total of 296 singleton pregnant women were classified into four groups according to the thyroid auto-antibody in the first trimester. Finally, there were 97 women in TPOAb positive group (TPOAb+/TgAb-), 35 in TgAb positive group (TPOAb-/TgAb+), 85 in TPOAb and TgAb positive group (TPOAb+/TgAb+), and 79 in TPOAb and TgAb negative group (TPOAb-/TgAb-). Thyroid function, TPOAb, and TgAb were checked during pregnancy and followed up at 6 weeks, 3 months, 6 months, 9 months, and 12 months postpartum. Levothyroxine sodium tablets could be taken to maintain euthyroid antepartum. Thyroid function of women with postpartum thyroiditis (PPT) were followed up at 2 and 3 years postpartum. We observed the incidence of PPT, premature rupture of membranes (PROM), placental abruption, placenta previa, polyhydramnios, oligohydramnios, postpartum hemorrhage, preterm birth, and low birth Weight in the four groups. 19.93% of the women had PPT. The incidence of PPT in TPOAb+/TgAb-, TPOAb-/TgAb+, TPOAb+/TgAb+groups was significantly higher than that in TPOAb-/TgAb- group, respectively (16.49 vs. 6.33%, 22.86 vs. 6.33%, 35.29 vs. 6.33%, p <0.05). The incidence of PPT in TPOAb+/TgAb+group was significantly higher than that in TPOAb+/TgAb- group (35.29 vs. 16.49%, p <0.01). PPT occurred as early as 6 weeks postpartum, but mainly at 3 and 6 months postpartum in the four groups (62.50%, 75.00%, 70.00%, 80.00%). All PPT in TPOAb-/TgAb- group occurred within 6 months postpartum, while it was found at 9 months or 12 months postpartum in other three groups. There was no classical form of PPT in TPOAb-/TgAb- group, while in the other three groups, all three types (classical form, isolated thyrotoxicosis, isolated hypothyroidism) existed. At 2 years postpartum of the women with PPT, the rate of euthyroidism in TPOAb+/TgAb+group was significantly lower than that in TPOAb-/TgAb- group (p <0.05). At 3 years postpartum of the women with PPT, the rate of euthyroidism in TPOAb+/TgAb-, TPOAb-/TgAb+, and TPOAb+/TgAb+groups were significantly lower than that in TPOAb-/TgAb- group (p <0.05). The values of TPOAb and TgAb postpartum were significantly higher than those during pregnancy (p <0.05). The incidence of PROM in TPOAb+/TgAb- group was significantly higher than that in TPOAb-/TgAb- group (32.99 vs. 17.72%, p <0.05). The binary logistic regression for PPT showed that the OR value of TPOAb was 2.263 (95% CI 1.142-4.483, p=0.019). The OR value of TgAb was 3.112 (95% CI 1.700-5.697, p=0.000). In conclusion, pregnant women with positive thyroid auto-antibodies had an increased risk of PPT and a reduced rate of euthyroidism at 2 and 3 years postpartum. TPOAb is associated with the incidence of PROM. Both of TPOAb and TgAb were independent risk factors for PPT. TgAb deserves more attention when studying autoimmune thyroid disease (AITD) combined with pregnancy.

The expression of anti-protein disulfide isomerase A3 autoantibody is associated with the increased risk of miscarriage in euthyroid women with thyroid autoimmunity

Miscarriage frequently occurs in euthyroid women with thyroid autoimmunity (TAI), but its mechanisms remain unclear. Our previous study has found that the serum level of anti-protein disulfide isomerase A3 autoantibody (PDIA3Ab) was significantly increased in mice with TAI. This study was aimed to explore whether there could be an association between the expression of PDIA3Ab and the occurrence of miscarriage in euthyroid TAI women. It was found that the serum level of PDIA3Ab was significantly increased in euthyroid TAI women as compared with that of non-TAI controls. Especially, serum PDIA3Ab level was markedly higher in euthyroid TAI women with miscarriage than the ones without miscarriage. Furthermore, binary logistic regression analysis showed that the serum PDIA3Ab level was an independent risk factor for spontaneous abortion in euthyroid TAI women with an odds ratio of 13.457 (95% CI, 2.965-61.078). The receiver operating characteristic (ROC) analysis of serum PDIA3Ab expression for predicting the miscarriage in euthyroid TAI women showed that the area under the curve was 0.707 ± 0.05 (P < 0.001). The optimal cut-off OD450 value of serum PDIA3Ab was 0.7129 with a sensitivity of 52.5% and specificity of 86.3% in euthyroid TAI women. Trend test showed that the prevalence of spontaneous abortion was markedly increased with the rise of serum PDIA3Ab level among TAI women in a titer-dependent manner. In conclusion, serum PDIA3Ab expression may imply an increased risk of spontaneous abortion in euthyroid TAI women, and it can be used as a new predictive bio-marker.

Does foetal gender influence maternal thyroid parameters in pregnancy?

Objective

It is unknown if foetal gender influences maternal thyroid function during pregnancy. We therefore investigated the prevalence of thyroid disorders and determined first-trimester TSH reference ranges according to gender.

Methods

A cross-sectional study involving 1663 women with an ongoing pregnancy was conducted. Twin and assisted pregnancies and l-thyroxine or antithyroid treatment before pregnancy were exclusion criteria. Serum TSH, free T4 (FT4) and thyroid peroxidase antibodies (TPOAb) were measured at median (interquartile range; IQR) 13 (11-17) weeks of gestation. Subclinical hypothyroidism (SCH) was present when serum TSH levels were >3.74 mIU/L with normal FT4 levels (10.29-18.02 pmol/L), and thyroid autoimmunity (TAI) was present when TPOAb were ≥60 kIU/L.

Results

Eight hundred and forty-seven women were pregnant with a female foetus (FF) and 816 with a male foetus (MF). In women without TAI and during the gestational age period between 9 and 13 weeks (with presumed high-serum hCG levels), median (IQR range) serum TSH in the FF group was lower than that in the MF group: 1.13 (0.72-1.74) vs 1.24 (0.71-1.98) mIU/L; P = 0.021. First-trimester gender-specific TSH reference range was 0.03-3.53 mIU/L in the FF group and 0.03-3.89 mIU/L in the MF group. The prevalence of SCH and TAI was comparable between the FF and MF group: 4.4% vs 5.4%; P = 0.345 and 4.9% vs 7.5%; P = 0.079, respectively.

Conclusions

Women pregnant with an MF have slightly but significantly higher TSH levels and a higher upper limit of the first-trimester TSH reference range, compared with pregnancies with a FF. We hypothesise that this difference may be related to higher hCG levels in women pregnant with a FF, although we were unable to measure hCG in this study. Further studies are required to investigate if this difference has any clinical relevance.

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.

Association of thyroid disorders with gestational diabetes mellitus: a meta-analysis

PURPOSE

The current meta-analysis aimed to evaluate the association of thyroid dysfunction and autoimmunity with gestational diabetes mellitus (GDM).

METHODS

A comprehensive search from PubMed, Embase, MEDLINE, and Cochrane databases until November 2020 was conducted. Fixed-effect model was used to combine the results when I² was <50%. Random-effect model was used to summarize the results when I² was >50%.

RESULTS

A total of 44 studies were included in the meta-analysis. Low FT4 levels were closely related with GDM in the first and second trimesters of gestation. Hypothyroxinemia (OR: 1.45; 95% CI: 1.25, 1.68; P < 0.00001), overt (OR: 1.80; 95% CI: 1.73, 1.86; P < 0.00001), and subclinical (OR: 1.54; 95% CI: 1.03, 2.30; P = 0.03) hypothyroidism, overt hyperthyroidism (OR: 1.49; 95% CI: 1.09, 2.04; P = 0.01), and positive thyroid antibodies (OR: 1.49; 95% CI: 1.07, 2.07; P < 0.00001) were observed significantly associated with the risk of GDM. Pregnant women with subclinical hyperthyroidism were less likely to develop GDM (OR: 0.62; 95% CI: 0.39, 0.97; P = 0.04).

CONCLUSIONS

Thyroid dysfunction and positive thyroid antibodies were associated with the risk of GDM. Our findings suggest that pregnant women with these thyroid diseases may be offered screening for GDM comprehensively.