The Need for Dynamic Clinical Guidelines: A Systematic Review of New Research Published After Release of the 2017 ATA Guidelines on Thyroid Disease During Pregnancy and the Postpartum

Fetal sexual dimorphism of maternal thyroid function parameters during pregnancy, a single center retrospective real-world study

Introduction

Thyroid function during pregnancy fluctuates with gestational weeks, seasons and other factors. However, it is currently unknown whether there is a fetal sex-specific thyroid function in pregnant women. The purpose of this study was to investigate the fetal sex differences of maternal thyroid-stimulating hormone (TSH) and free thyroxine (FT4) in pregnant women.

Methods

This single-center retrospective real-world study was performed by reviewing the medical records of pregnant women who received regular antenatal health care and delivered liveborn infants in Shanghai First Maternity and Infant Hospital (Pudong branch), from Aug. 18, 2013 to Jul. 18, 2020. Quantile regression was used to evaluate the relationship between various variables and TSH and FT4 concentrations. The quantile regression also evaluated the sex impact of different gestational weeks on the median of TSH and FT4.

Results

A total of 69,243 pregnant women with a mean age of 30.36 years were included. 36197 (52.28%) deliveries were boys. In the three different trimesters, the median levels (interquartile range) of TSH were 1.18 (0.66, 1.82) mIU/L and 1.39 (0.85, 2.05) mIU/L, 1.70 (1.19, 2.40) mIU/L; and the median levels (interquartile range) of FT4 were 16.63 (15.16, 18.31) pmol/L, 14.09 (12.30, 16.20) pmol/L and 13.40 (11.52, 14.71) pmol/L, respectively. The maternal TSH upper limit of reference ranges was decreased more in mothers with female fetuses during gestational weeks 7 to 12, while their FT4 upper limit of the reference ranges was increased more than those with male fetuses. After model adjustment, the median TSH level was 0.11 mIU/L lower (P <0.001), and FT4 level was 0.14 pmol/L higher (P <0.001) for mothers with female fetuses than those with male fetuses during gestational weeks 9 to 12.

Discussion

We identified sexual dimorphism in maternal thyroid function parameters, especially during 9-12 weeks of pregnancy. Based on previous research, we speculated that it may be related to the higher HCG levels of mothers who were pregnant with girls during this period. However, longitudinal studies are needed to determine if fetal sex differences impact the maternal thyroid function across pregnancy.

Recommendations of the AGG (Working Group for Obstetrics, Department of Maternal Diseases) on How to Treat Thyroid Function Disorders in Pregnancy

Objective These recommendations from the AGG (Committee for Obstetrics, Department of Maternal Diseases) on how to treat thyroid function disorder during pregnancy aim to improve the diagnosis and management of thyroid anomalies during pregnancy.

Methods Based on the current literature, the task force members have developed the following recommendations and statements. These recommendations were adopted after a consensus by the members of the working group.

Recommendations The following manuscript gives an insight into physiological and pathophysiological thyroid changes during pregnancy, recommendations for clinical and subclinical hypo- and hyperthyroidism, as well as fetal and neonatal diagnostic and management strategies.

Pregnancy outcomes and newborn characteristics in women with follicular fluid thyroid autoantibodies undergoing assisted reproduction

Background

Higher levels of thyroid autoantibodies in follicular fluid (FF) of thyroid autoimmunity (TAI) positive women are strongly correlated with serum levels and may have effect on the post-implantation embryo development. Literature highlights that levothyroxine (LT4) treatment may attenuate the risk of adverse pregnancy outcomes. The aim of the study was to estimate the pregnancy and newborn outcomes in women with FF thyroid autoantibodies undergoing assisted reproductive technology (ART).

Methods

The study population included 24 women with confirmed clinical pregnancy, 8 TAI positive and 16 TAI negative women. LT4 supplementation was applied in 20.8% patients, TAI positive.

Results

Pregnancy outcomes were: twin pregnancy rate 41.7%, early miscarriage rate 8.3%, late miscarriage rate 4.2%, preterm birth rate 16.7%, term birth rate 70.8%, live birth rate 96.0%. There was significant difference in serum and in FF TgAbs (p< 0.001)between the groups according to TAI, while serum fT₃ was lower in the group with TAI (p = 0.047). Serum P₄ was higher in LT4 treated group (p = 0.005), with TAI, and newborns in this group had higher birth weight (p = 0.001) and height (p = 0.008). Maternal complications occurred in 23.8% of patients. No congenital malformations in newborns were noted.

Conclusions

Thyroid autoantibodies present in FF may have an effect on the post-implantation embryo development, but have no effect on further course of pregnancy. The special benefit of LT4 treatment for successful ART outcome was demonstrated for newborn anthropometric parameters.

A Bayesian model to estimate the cutoff value of TSH for management of preterm birth

BACKGROUND

Determining a thyroid hormone cutoff value in pregnancy is challenging issue and several approaches have been introduced to optimize a utility function. We aimed to estimate the cutoff value of TSH using Bayesian method for prediction of preterm-birth.

METHODS

This study was a secondary-analysis of the population-based data collected prospectively within the framework of the Tehran Thyroid and Pregnancy Study. A total of 1,538 pregnant women attending prenatal clinics.

RESULTS

Using Bayesian method resulted a TSH-cutoff of (3.97mIU/L,95%CI:3.95-4.00) for distinguishing pregnant women at risk of preterm-birth. The cutoff was associated with acceptable positive predictive and negative predictive values (0.84,95% CI:0.80-0.88) and 0.92 (95%CI: 0.91-0.94), respectively). In women who were negative for thyroid peroxides antibody (TPOAb) with sufficient urinary iodine concentration (UIC), the TSH cutoff of 3.92 mIU/L(95%CI:3.70-4) had the highest predictive value; whereas in TPOAb positive women with insufficient UIC, the cutoff of 4.0 mIU/L(95%:CI 3.94-4) could better predict preterm birth. Cutoffs estimated in this study are close to the revised TSH value of 4.0mIU/L which is currently recommended by the American Thyroid Association.

CONCLUSION

Regardless of TPOAb status or iodine insufficiency, risk of preterm labor is increased in pregnant women with TSH value of > 3.92 mIU/L; these women may benefit from Levothyroxine (LT4) therapy for preventing preterm birth.

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.

Impact of Thyroid Function on Pregnancy and Neonatal Outcome in Women with and without PCOS

Background: Women with polycystic ovary syndrome (PCOS) are more prone to autoimmune thyroiditis, and both disorders lead to subfertility and pregnancy-related complications. The aim of this study was to investigate whether mothers with and without PCOS and their offspring have comparable thyroid parameters at term and how thyroid parameters are associated with perinatal outcome in this population. Methods: This cross-sectional observational study was performed in a single academic tertiary hospital in Austria. Seventy-nine pregnant women with PCOS and 354 pregnant women without PCOS were included. Blood samples were taken from the mother and cord blood at birth. Primary outcome parameters were maternal and neonatal thyroid parameters at delivery. Secondary outcome parameters were the composite complication rate per woman and per neonate. Results: Thyroid dysfunction was more prevalent among PCOS women (p < 0.001). At time of birth, free triiodothyronine (fT3) levels were significantly lower in PCOS than in non-PCOS women (p = 0.005). PCOS women and their neonates had significantly higher thyreoperoxidase antibody (TPO-AB) levels (p = 0.001). Women with elevated TPO-AB had a significantly higher prevalence of hypothyroidism (p < 0.001). There was a significant positive correlation between maternal and neonatal free thyroxine, fT3 and TPO-AB levels. There were no significant differences in thyroid parameters between women or neonates with or without complications. Conclusions: Our results demonstrate a higher prevalence of thyroid dysfunction and autoimmunity in PCOS women, supporting a common etiology of both disorders. We were not able to show an association between complication rate and thyroid parameters.

[Diagnostic and treatment of subclinical hypothyroidism in pregnant and planning pregnancy patients: modern view of the problem]

There is no universal diagnostic and treatment strategy of subclinical hypothyroidism (SHT) in pregnant women and those who are planning pregnancy due to differences in population-specific and trimester-specific thyroid-stimulating hormone (TSH) reference values, influence of thyroid autoimmunity markers on pregnancy outcomes, adherence to fixed universal cutoff concentrations TSH in Russia and multidisciplinary team care with different treatment opinions involving. An absence of universal approach to SHT leads to excess treatment, financial and psychological burden on pregnant women.Up to American Thyroid Association (ATA) Guidelines 2017 and project of Clinical Guidelines of Russian Association of Endocrinologists 2019 a treatment strategy of SHT should be left up to the endocrinologist to choose. In our paper we systematize global scientific and clinical experience of planning and management pregnancies with SHT to help physicians to choose treatment option based on principals of evidence-based medicine.

Schilddrüse: Fertilität, Schwangerschaft und Laktation

Schilddrüsenhormone und Schilddrüsenerkrankungen spielen eine wichtige Rolle bei Fertilität, Schwangerschaft und Laktation. Die diversen Richtlinien und Expertenempfehlungen zur Diagnostik und Therapie von Schilddrüsenerkrankungen bei Kinderwunsch und Schwangerschaft sind teils heterogen und oftmals ohne klare Handlungsanweisung für oder gegen eine bestimmte Maßnahme, was eine gewisse Verunsicherung hervorruft. In diesem Übersichtsartikel möchten wir daher die derzeitige Evidenz auf diesem Gebiet in Bezug auf praktische Handlungsanweisungen darlegen, um dem Leser für die Praxis eine nützliche Entscheidungshilfe an die Hand zu geben. Wir werden besonders auf die aktuelle Evidenzlage bzgl. der Behandlung der latenten Hypothyreose präkonzeptionell, bei Infertilität und in der Schwangerschaft eingehen, sowie auf die Wichtigkeit der Beratung und gemeinsamen Therapieentscheidung bei Hyperthyreose und Kinderwunsch bzw. Schwangerschaft. Wir möchten auch besonders betonen, dass diverse wichtige Studien erst nach Publikation der aktuellen Richtlinien auf diesem Gebiet veröffentlicht wurden, was in der Routinebehandlung unserer Patientinnen natürlich berücksichtigt werden sollte. Da manifeste Schilddrüsenerkrankungen präkonzeptionell und in der Schwangerschaft häufig und in der Regel therapiebedürftig sind, plädieren wir für ein generelles Screening auf Schilddrüsenfunktionsstörungen bei allen Frauen mit Kinderwunsch sowie bei allen mit positivem Schwangerschaftstest.