In vitro fertilization pregnancy rates in levothyroxine-treated women with hypothyroidism compared to women without thyroid dysfunction disorders

From Conception to Delivery: A Comprehensive Review of Thyroid Disorders and Their Far-Reaching Impact on Feto-Maternal Health

This comprehensive review delves into the multifaceted landscape of thyroid disorders during pregnancy, exploring their impact from conception to postpartum considerations. Key findings highlight the intricate interplay between maternal thyroid health and fetal development, emphasizing the critical importance of timely screening and targeted interventions. The evolving landscape of research and technology suggests a paradigm shift toward personalized approaches in clinical practice, emphasizing integrated care models and the integration of telehealth platforms. Postpartum considerations, including postpartum thyroiditis, underscore the necessity for ongoing monitoring and intervention for maternal well-being. Implications for clinical practice encompass healthcare provider education, public awareness campaigns, and policy advocacy for standardized screening guidelines. The call to action resonates for increased research funding to advance understanding and improve outcomes. By fostering awareness, education, and collaborative efforts, this review aims to navigate the complexities of thyroid disorders during pregnancy, ensuring a healthier start for both mothers and their infants.

A Case Report Based on a Holistic Approach to Improve Assisted Reproductive Technology (ART) Pregnancy Outcomes in a Patient With Thyroid Dysfunction

To address infertility in a 34-year-old woman with hypothyroidism, this case study investigated an integrated holistic therapy approach. The woman presented with primary infertility and sought treatment at an infertility centre in Maharashtra, India. She underwent thorough evaluations for infertility, revealing a history of hypothyroidism. The therapy strategy included a six-month course of 50 mg levothyroxine, along with yoga and yog nidra. The yoga interventions, incorporating techniques such as surya namaskar, kriyas, yoga asanas, and pranayama, proved beneficial for weight management, stress reduction, and overall well-being. The deep relaxation method known as yog nidra played a crucial role in achieving hormonal balance. After six months, the patient's body mass index (BMI) improved from 28 to 24, and the male partner's semen analysis showed results within normal limits. The patient's thyroid-stimulating hormone (TSH) levels also returned to the normal range. Further in-vitro fertilization (IVF) treatment, including a successful embryo transfer, resulted in a positive clinical pregnancy test. This research underscores the effectiveness of alternative therapies like yoga and meditation in conjunction with traditional medicine to address both the psychological and physiological components of infertility caused by hypothyroidism. The case suggests that an integrated approach like this could offer a comprehensive solution for infertile couples. However, for broader applicability, additional investigation and clinical validation are warranted.

Thyroid dysfunction and female infertility. A comprehensive review

INTRODUCTION

Female infertility is defined as the inability to achieve pregnancy following one year of consistent, unprotected sexual intercourse. Among the various endocrine factors contributing to this complex issue, thyroid dysfunction assumes a pivotal and noteworthy role.

METHODS

A narrative review, encompassing 134 articles up to 2023, was conducted utilizing the PubMed/Medline, EMBASE, and Scielo databases. The primary focus of this review was to investigate the effects of thyroid dysfunction on female infertility.

RESULTS

Thyroid disorders exert a significant influence on folliculogenesis, fertilization, and implantation processes. Thyroid autoimmunity, although associated with diminished ovarian reserve, does not typically necessitate levothyroxine therapy. On the other hand, both subclinical and overt hypothyroidism often require levothyroxine treatment to enhance fertility and optimize obstetric outcomes. Hyperthyroidism warrants prompt intervention due to its heightened risk of miscarriage. Furthermore, thyroid dysfunction exerts notable effects on assisted reproductive technologies, underscoring the importance of achieving euthyroidism prior to ovarian stimulation.

CONCLUSION

Women presenting with thyroid dysfunction must undergo meticulous and individualized assessments since fertility outcomes, whether achieved through natural conception or assisted reproductive technologies, can be significantly influenced by thyroid-related factors.

Maternal hypothyroidism and its effect on placental histopathology in singleton live births resulting from in vitro fertilization treatment

We aimed to examine the impact of maternal hypothyroidism on placental pathology and perinatal outcomes in singleton live births resulting from IVF, using medical records of IVF births between 2009 and 2017 at a tertiary hospital. The primary outcomes included anatomical, inflammation, vascular malperfusion, and villous maturation placental features. Secondary outcomes included foetal, maternal, perinatal, and delivery complications. There were 1,057 live births, of which 103 (9.7%) and 954 (90.3%) were in the study and control groups, respectively. Patients in the study group were more likely to have diabetes mellitus, polycystic ovarian syndrome, gestational diabetes mellitus, and non-reassuring foetal heart rate (NRFHR) tracing during delivery. After adjustment for potential confounding factors, hypothyroidism was significantly associated with the bilobed placenta (aOR 4.1; 95% CI 1.2-14.3), retroplacental haematoma (aOR 2.4; 95% CI 1.2-4.9), decidual arteriopathy (aOR 2.0; 95% CI 1.2-4.1) and subchorionic thrombi (aOR 2.4; 95% CI 1.3-5.0). Additionally, there was a statistically significant relationship with NRFHR tracing. The incidence of acute chorioamnionitis and severe foetal inflammatory response was higher in the study group. In conclusion, the placental histopathology patterns of singleton IVF live births show that maternal hypothyroidism has a significant impact on adverse perinatal outcomes.

Nutritional management and interventions in complications of pregnancy: A systematic review

Background: Pregnancy, also known as the "gestation period" which lasts for 37-40 weeks, has been marked as the period of "physiological stress" in a woman's life. A wide range of symptoms, from nausea to ectopic pregnancy, are usually aligned with risk factors like abortion, miscarriage, stillbirth, etc. An estimated total of 15% of total pregnant women face serious complications requiring urgent attention for safe pregnancy survival. Over the past decades, several changes in the environment and nutrition habits have increased the possibility of unfavourable changes during the gestation phase. The diagnostic factors, management and nutritional interventions are targeted and more emphasis has been laid on modifying or managing the nutritional factors in this physiologically stressed phase. Aims: This review focuses on dietary modifications and nutritional interventions for the treatment of complications of pregnancy. Nutritional management has been identified to be one of the primary necessities in addition to drug therapy. It is important to set a healthy diet pattern throughout the gestation phase or even before by incorporating key nutrients into the maternal diet. Methods: The published literature from various databases including PubMed, Google Scholar and ScienceDirect were used to establish the fact of management and treatment of complications of pregnancy. Results: The recommendations of dietary supplements have underlined the concept behind the eradication of maternal deficiencies and improving metabolic profiles. Conclusion: Therefore, the present review summarises the dietary recommendations to combat pregnancy-related complications which are necessary in order to prevent and manage the same.

Thyroid hormone enhances stem cell maintenance and promotes lineage-specific differentiation in human embryonic stem cells

Background

Thyroid hormone triiodothyronine (T3) is essential for embryogenesis and is commonly used during in vitro fertilization to ensure successful implantation. However, the regulatory mechanisms of T3 during early embryogenesis are largely unknown.

Method

To study the impact of T3 on hPSCs, cell survival and growth were evaluated by measurement of cell growth curve, cloning efficiency, survival after passaging, cell apoptosis, and cell cycle status. Pluripotency was evaluated by RT-qPCR, immunostaining and FACS analysis of pluripotency markers. Metabolic status was analyzed using LC–MS/MS and Seahorse XF Cell Mito Stress Test. Global gene expression was analyzed using RNA-seq. To study the impact of T3 on lineage-specific differentiation, cells were subjected to T3 treatment during differentiation, and the outcome was evaluated using RT-qPCR, immunostaining and FACS analysis of lineage-specific markers.

Results

In this report, we use human pluripotent stem cells (hPSCs) to show that T3 is beneficial for stem cell maintenance and promotes trophoblast differentiation. T3 enhances culture consistency by improving cell survival and passaging efficiency. It also modulates cellular metabolism and promotes energy production through oxidative phosphorylation. T3 helps maintain pluripotency by promoting ERK and SMAD2 signaling and reduces FGF2 dependence in chemically defined culture. Under BMP4 induction, T3 significantly enhances trophoblast differentiation.

Conclusion

In summary, our study reveals the impact of T3 on stem cell culture through signal transduction and metabolism and highlights its potential role in improving stem cell applications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02799-y.

Growth hormone replacement improved oocyte quality in a patient with hypopituitarism: a study of follicular fluid

BACKGROUNDː Growth hormone (GH) is known to be involved in ovarian folliculogenesis and oocyte maturation. In patients with poor ovarian response without growth hormone deficiency (GHD), adjuvant GH treatment improves in-vitro fertilization (IVF) results. Improvement of oocyte quality in IVF by GH replacement was reported in only a few patients with GHD. We report on another case with study of follicular fluid. METHODSː A 29-year-old patient with hypopituitarism was referred to our infertility center. She was undergoing hormonal replacement for hypogonadotropic hypogonadism and diabetes insipidus, and did not at first want GH replacement. Four IVF procedures were performed between 2011 and 2014. Growth hormone replacement (somatotropin 1.1mg/day) was initiated before the fourth IVF procedure and unmasked central hypothyroidism; levothyroxine (75 mg/day) was introduced. It took 10 months to reach the treatment objectives for insulin-like growth factor 1 (IGF1), free triiodothyronine (fT3) and free thyroxine (fT4). GH, IGF1 and thyroid hormones were measured in the blood and follicular fluid before and after GH and thyroid hormone replacement. Oocyte and embryo quality were also compared. RESULTSː The first 3 IVF procedures were performed without GH replacement. 62% to 100% of mature oocytes presented one or more morphologic abnormalities: diffuse cytoplasmic granularity, large perivitelline space with fragments, fragmentation of the first polar body, ovoid shape, or difficult denudation. Embryo quality was moderate to poor (grade B to D), and no pregnancy was obtained after embryo transfer. After GH replacement, hormones levels increased in follicular fluid: GH [7.68 vs. 1.39 mIU/L], IGF1 [109 vs. <25 ng/mL], fT3 [3.7 vs. 2.5 pmol/L] and fT4 [1.45 vs. 0.84 ng/mL]. Concomitantly, there was dramatic improvement in oocyte quality (no abnormal morphologies) and embryo quality (grade A), allowing an embryo transfer with successful pregnancy. CONCLUSIONSː This is the first report illustrating changes in hormonal levels in follicular fluid and the beneficial effect of GH replacement on oocyte and embryo quality during an IVF procedure in a patient with hypopituitarism. These results suggest that GH replacement is beneficial for oocyte quality in patients with GHD.

Preconception Evaluation Before In Vitro Fertilization

Importance

Infertility poses a substantial public health problem for women of reproductive age, in the United States and globally. Infertility can be overcome with a variety of emerging assisted reproductive technologies (ARTs). In vitro fertilization (IVF) currently represents the most commonly utilized method of ART and is typically associated with the highest clinical pregnancy rate and live birth rate compared with other infertility treatment options. However, proper preconception evaluation and counseling is paramount for optimizing IVF and pregnancy outcomes.

Objective

This article aims to outline current guidelines and recommendations for comprehensive preconception evaluation before initiation of IVF.

Evidence Acquisition

Articles were obtained from PubMed, ACOG committee opinions 781 and 762, and relevant textbook chapters.

Results

A variety of recommendations and best practices exist for optimally managing patients seeking IVF. Special attention must be paid to the workup of certain patient populations, such as those with age older than 35 years, uterine abnormalities, comorbidities (especially hypertension, diabetes, and thrombophilias), and obesity. In addition, many lifestyle factors must be addressed before IVF initiation, such as smoking, illicit drug use, and inadequate nutrition. Preconception counseling and expectation management is key to optimizing pregnancy outcome.

Conclusion and Relevance

A myriad of patient and environmental factors impact the potential success rates of IVF in treating infertility. Providers must be equipped to provide data-driven, patient-centered counseling before initiation of IVF.

Thyroid Disorders and In Vitro Outcomes of Assisted Reproductive Technology: An Unfortunate Combination?

Background: The impact of thyroid disorders on in vitro outcomes of assisted reproductive technology (ART) remains controversial. Therefore, the aim of our study was to investigate whether thyroid peroxidase antibodies (TPO-Abs)/thyroid autoimmunity (TAI) or thyroid function (serum thyrotropin [TSH])/subclinical hypothyroidism are associated with an altered number of oocyte retrieval (NOR), fertilization rate (FR), and embryo quality (EQ). Methods: Cross-sectional study in 279 women in a single center, comprising 297 cycles and 1168 embryos. In vitro data (NOR, FR, and EQ) were documented in two groups; one according to thyroid function in women without TAI (TSH ≤2.5 and >2.5 mIU/L) and one according to the presence/absence of TAI (determined by TPO-Abs). EQ was evaluated according to international criteria and classified as excellent/good and poor. Women treated with levothyroxine (LT4) were excluded. Furthermore, the impact of thyroid parameters on outcomes, normal NOR (>6 or 8) and high FR (>60%), was verified in a multivariable logistic regression model. Results: In women without TAI, 27% had TSH levels >2.5 mIU/L, the prevalence of TAI was 8%, and overall, 6% of women had TSH levels >4.2 mIU/L. NOR, FR, and EQ were comparable between study groups. In the regression analysis, women aged ≥30 years and receiving a high ovarian stimulation dosage (>2300 IU/cycle) had lower rates of normal NOR (odds ratio [OR] 0.18 [95% confidence interval, CI 0.04-0.72]; p = 0.016 and OR 0.17 [CI 0.06-0.48]; p < 0.001, respectively). Conclusions: Our results do not suggest an impact of thyroid antibodies/autoimmunity and (dys)function on ART in vitro outcomes.

Hypothalamic-Pituitary-Ovarian Axis Disorders Impacting Female Fertility

The hypothalamic-pituitary-ovarian (HPO) axis is a tightly regulated system controlling female reproduction. HPO axis dysfunction leading to ovulation disorders can be classified into three categories defined by the World Health Organization (WHO). Group I ovulation disorders involve hypothalamic failure characterized as hypogonadotropic hypogonadism. Group II disorders display a eugonadal state commonly associated with a wide range of endocrinopathies. Finally, group III constitutes hypergonadotropic hypogonadism secondary to depleted ovarian function. Optimal evaluation and management of these disorders is based on a careful analysis tailored to each patient. This article reviews ovulation disorders based on pathophysiologic mechanisms, evaluation principles, and currently available management options.

Levothyroxine supplementation on assisted reproduction technology (ART) outcomes in women with subtle hypothyroidism: a retrospective study

The need for treating subclinical hypothyroidism (SCH) in women undergoing assisted reproduction technology (ART) is under debate. Moreover, it is known that controlled ovarian hyperstimulation (COH) protocols may impair the thyroidal axis. Therefore, we evaluated if levothyroxine (L-T4) supplementation in SCH women before undergoing ART positively affects the main reproductive outcomes. We retrospectively analyzed in vitro fertilization (IVF) data of 4147 women submitted to 6545 cycles in a tertiary care IVF Center (January 2009-December 2014). L-T4 (1.4-2.0 mcg/kg) treatment was offered to all women with a pre-cycle TSH >2.5 mIU/L before starting COH and main ART outcomes were compared in euthyroid and L-T4-treated women undergoing ART. Among 4147 women, 1074 (26%) were affected by SCH and were treated with L-T4 before COH was started. No statistically significant differences among L-T4-treated and euthyroid women group were observed regarding pregnancy rate, respectively, per cycle (27.67% vs 26.37%; p = .314) and per embryo transfer (30.13% vs 29.17%; p = .489), live birth rate, respectively, per cycle (21.58% vs 20.38%; p = .304) and per embryo transfer (23.49 vs 22.54%; p = .449) and the rest of primary and secondary efficacy endpoints. Early L-T4 treatment for infertile women with a subtle thyroid dysfunction may mitigate and protect from the negative effects of SCH in the setting of ART, and may preventively overcome also the negative impact of COH on thyroidal axis.

The impact of thyroid-stimulating hormone levels in euthyroid women on intrauterine insemination outcome

Background

The aim of this study was to examine the effect of thyroid-stimulating hormone (TSH) levels on intrauterine insemination (IUI) outcomes among euthyroid women.

Methods

A retrospective cohort study was conducted. A total of 302 women who started their first IUI cycle in our fertility center were included in this study. The patients were categorized into two groups based on their preconception TSH values: 0.38–2.49 mIU/Land 2.50–4.99 mIU/L. The clinical pregnancy rate was the main outcome parameter. As secondary parameters, we evaluated the differences in spontaneous abortion rate, live-birth delivery rate, and perinatal outcomes according to the preconception TSH threshold (< 2.5 and < 5.00 mIU/L).

Results

There was no significant difference between the two groups with respect to clinical pregnancy, miscarriage, and live-birth rates with an odds ratio of 1.67 (95% CI: 0.79–3.53), 1.08 (95% CI: 0.09–13.1), and 1.79 (95% CI: 0.77–4.2), respectively. In addition, there were no significant differences in perinatal outcomes (gestation at delivery, birth weight, and neonatal intensive care unit–administration rate) between the two groups.

Conclusions

Our findings indicate that among euthyroid patients, preconception TSH values in the high-normal range (between 2.5 and 4.9 mIU/L) do not have a negative effect on IUI outcomes.

Trial registration

This study is retrospectively registered by Ethical Review Board at Inonu University in 19th December 2017; Ethics approval no is 2017–27-20.

Thyroid autoimmunity and intracytoplasmic sperm injection outcome: a systematic review and meta-analysis

BACKGROUND

Since 2010, three meta-analyses have been published on the impact of thyroid autoimmunity (TAI) on pregnancy outcomes in infertile women treated with assisted reproductive technology (ART). The initially observed high risk of miscarriage became very low in the most recent meta-analysis published in 2016.

OBJECTIVE

To investigate whether the lower risk of miscarriage in the latest meta-analysis was associated with the increased use of intracytoplasmic sperm injection (ICSI) in recent studies.

DATA SOURCE

MEDLINE was searched from January, 1990, to May, 2017.

STUDY SELECTION

Data from case-control and cohort studies, on ART (IVF/ICSI) pregnancy outcomes in women with and without TAI. Only studies were included in which women were treated with ICSI.

DATA EXTRACTION AND SYNTHESIS

Four studies were retained including 1855 ICSI cycles (290 with and 1565 without TAI). In women with a clinical pregnancy (114 ICSI cycles with TAI and 651 without), there was no difference in miscarriage or live birth rates: respective combined OR 0.95 (95% CI, 0.48 to 1.87) and 1.12 (95% CI, 0.62 to 2.03). There was no difference in age in women with and without TAI: combined mean difference of 0.13 years (95% CI, -0.51 to 0.76), but serum TSH was higher in women with TAI: combined mean difference of 0.20 mIU/L (95% CI, 0.07 to 0.33).

CONCLUSION

Infertile women with TAI treated with ICSI had no increased risk of a first trimester miscarriage compared with women without TAI.

Paternal urinary concentrations of organophosphate flame retardant metabolites, fertility measures, and pregnancy outcomes among couples undergoing in vitro fertilization

BACKGROUND

Use of organophosphate flame retardants (PFRs) has increased over the past decade following the phase out of some brominated flame retardants, leading to increased human exposure. We recently reported that increasing maternal PFR exposure is associated with poorer pregnancy outcomes among women from a fertility clinic. Because a small epidemiologic study previously reported an inverse association between male PFR exposures and sperm motility, we sought to examine associations of paternal urinary concentrations of PFR metabolites and their partner's pregnancy outcomes.

METHODS

This analysis included 201 couples enrolled in the Environment and Reproductive Health (EARTH) prospective cohort study (2005-2015) who provided one or two urine samples per IVF cycle. In both the male and female partner, we measured five urinary PFR metabolites [bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), diphenyl phosphate (DPHP), isopropylphenyl phenyl phosphate (ip-PPP), tert-butylphenyl phenyl phosphate (tb-PPP) and bis(1-chloro-2-propyl) phosphate (BCIPP)] using negative electrospray ionization liquid chromatography tandem mass spectrometry (LC-MS/MS). The sum of the molar concentrations of the urinary PFR metabolites was calculated. We used multivariable generalized linear mixed models to evaluate the association of urinary concentrations of paternal PFR metabolites with IVF outcomes, accounting for multiple in vitro fertilization (IVF) cycles per couple. Models were adjusted for year of IVF treatment cycle, primary infertility diagnosis, and maternal urinary PFR metabolites as well as paternal and maternal age, body mass index, and race/ethnicity.

RESULTS

Detection rates were high for paternal urinary concentrations of BDCIPP (84%), DPHP (87%) and ip-PPP (76%) but low for tb-PPP (12%) and zero for BCIPP (0%). We observed a significant 12% decline in the proportion of fertilized oocytes from the first to second quartile of male urinary ΣPFR and a 47% decline in the number of best quality embryos from the first to third quartile of male urinary BDCIPP in our adjusted models. An 8% decline in fertilization was observed for the highest compared to lowest quartile of urinary BDCIPP concentrations (95% CI: 0.01, 0.12, p-trend=0.06).

CONCLUSIONS

Using IVF as a model to investigate human reproduction and pregnancy outcomes, we found that paternal urinary concentrations of BDCIPP were associated with reduced fertilization. In contrast to previously reported findings for the female partners, the paternal urinary PFR metabolites were not associated with the proportion of cycles resulting in successful implantation, clinical pregnancy, and live birth. These results indicate that paternal preconception exposure to TDCIPP may adversely impact successful oocyte fertilization, whereas female preconception exposure to ΣPFRs may be more relevant to adverse pregnancy outcomes.

Subclinical hypothyroidism: Is it important in intracytoplasmic sperm injection cycles?

OBJECTIVE

To compare intracytoplasmic sperm injection (ICSI) outcomes of women with subclinical hypothyroidism with those of euthyroid women.

MATERIALS AND METHODS

A retrospective case-control study was conducted. Out of 2529 ICSI cycles evaluated, 41 women with hypothyroidism, 28 women with hyperthyroidism, and 128 women with subclinical hyperthyroidism were excluded, and 2336 cycles were analyzed. Women were identified as having subclinical hypothyroidism (case group, n=105) in the presence of a thyroid-stimulating hormone level >4.5 mU/L and normal free T4 and compared with euthyroid controls (n=2231).

RESULTS

The mean age, body mass index, day 3 follicle-stimulating hormone level, and antral follicle count of the study patients were similar to the control group (p>0.5). The cycle cancellation rate of the study group was similar to the control group (13.3% vs. 7.6%, p=0.1). The clinical pregnancy rate was 21.2% in the study group, which was significantly lower than the 35.8% in the control group (p=0.04). The take-home baby rate was also significantly lower in the study group compared with the control groups (13.5% vs. 31.4% respectively, p=0.01).

CONCLUSION

Both the clinical pregnancy rate and the take-home baby rate is lower in women with subclinical hypothyroidism at the time of ICSI cycle.

Urinary Concentrations of Organophosphate Flame Retardant Metabolites and Pregnancy Outcomes among Women Undergoing in Vitro Fertilization

BACKGROUND

Evidence from animal studies suggests that exposure to organophosphate flame retardants (PFRs) can disrupt endocrine function and impair embryo development. However, no epidemiologic studies have been conducted to evaluate effects on fertility and pregnancy outcomes.

OBJECTIVES

We evaluated associations between urinary concentrations of PFR metabolites and outcomes of in vitro fertilization (IVF) treatment among couples recruited from an academic fertility clinic.

METHODS

This analysis included 211 women enrolled in the Environment And Reproductive Health (EARTH) prospective cohort study (2005-2015) who provided one or two urine samples per IVF cycle. We measured five urinary PFR metabolites [bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), diphenyl phosphate (DPHP), isopropylphenyl phenyl phosphate (ip-PPP), tert-butylphenyl phenyl phosphate (tb-PPP), and bis(1-chloro-2-propyl) phosphate (BCIPP)] using negative electrospray ionization liquid chromatography tandem mass spectrometry (LC-MS/MS). Molar concentrations of the urinary PFR metabolites were summed. We used multivariable generalized linear mixed models to evaluate the association of the PFR metabolites with IVF outcomes, accounting for multiple IVF cycles per woman.

RESULTS

Detection frequencies were high for BDCIPP (87%), DPHP (94%), and ip-PPP (80%), but low for tb-PPP (14%) and BCIPP (0%). We observed decreased success for several IVF outcomes across increasing quartiles of both summed and individual PFR metabolites (DPHP and ip-PPP) in our adjusted multivariable models. Significant declines in adjusted means from the lowest to highest quartile of ΣPFR were observed for the proportion of cycles resulting in successful fertilization (10% decrease), implantation (31%), clinical pregnancy (41%), and live birth (38%).

CONCLUSIONS

Using IVF to investigate human reproduction and pregnancy outcomes, we found that concentrations of some urinary PFR metabolites were negatively associated with proportions of successful fertilization, implantation, clinical pregnancy, and live birth. https://doi.org/10.1289/EHP1021.

Thyroid peroxidase identified in human granulosa cells: another piece to the thyroid-ovary puzzle?

Thyroid hormones seemingly influence the maturation of the human oocyte. Thyroid hormone receptors have been isolated in granulosa mural and cumulus cells and the mature oocyte of the human ovarian follicle. Thyroid hormones are present in follicular fluid in concentrations similar to those in serum. Most importantly, enzymes involved in the chain that regulate the generation of thyroid hormones have been found in granulosa cells. For the first time, we have isolated thyroid peroxidase by immunocytochemistry in the granulosa cumulus cells of the human ovarian follicle, thereby supporting the hypothesis that the human ovarian follicle may be an independent thyroid-hormone producing unit.

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.

THYROID DYSFUNCTION AND INFERTILITY TREATMENT

Objective

To find out the relationship of thyroid hormone profile of females with outcomes after intra cytoplasmic sperm injection (ICSI).

Method

It was a cross sectional study conducted in Islamabad Clinic Serving Infertile Couple from June 2013 till August 2015. T3 (triiodo thyronine), T4 (thyroxine) and TSH (thyroid stimulating hormone) of 168 consented females was estimated after they underwent the first step of treatment protocol (ovarian down regulation) for ICSI. Pregnant group had ß hCG result more than 25 IU/mL while the rest were included in the non-pregnant group. Both groups were compared by using independent sample t-test. Pearson correlation coefficient was used to associate T3 and T4 with other pregnancy variables with their significance.

Results

Non pregnant women had significantly higher mean values for T3 and T4 as compared to pregnant women (p <0.05, p<0.01). Difference in mean TSH value between non-pregnant and pregnant women was not significant p=0.08. It was found that T4 gave significant negative association with grading of embryo-I, blastocysts formed, thickness of endometrium and number of gestational sacs.

Conclusion

Disturbance in thyroid profile with raised T4 levels leads to alteration in endometrial thickness and quality of embryos required for implantation and hence conception.

What affects functional ovarian reserve, thyroid function or thyroid autoimmunity?

BACKGROUND

Thyroid dysfunction is the most common autoimmune endocrine disorder in women of reproductive age, and is associated with menstrual irregularities, anovulation and infertility. Whether it is thyroid function or thyroid autoimmunity that affects functional ovarian reserve (FOR, i.e., the small growing ovarian follicle pool) reflected in anti-Müllerian hormone (AMH) has, however, remained under dispute.

METHODS

We investigated in 225 infertile women whether thyroid function, after adjustment for thyroid autoimmunity, affects FOR within what is considered normal thyroid function (TSH, 0.4-4.5μIU/mL) by assessing AMH levels in reference to TSH levels, stratified for TSH < or ≥3.0μIU/mL. Thyroid autoimmunity was defined by presence of anti-thyroid peroxidase, -thyroglobulin and/or -thyroid receptor antibodies.

RESULTS

Mean age of studied women was 38.4 ± 5.0 years; their mean AMH was 1.3 ± 2.0 ng/mL and mean TSH 1.8 ± 0.9 μIU/mL. Thyroid autoimmunity was present in 11.1 % of patients. Women with TSH <3.0μIU/mL presented with significantly higher AMH compared to those with TSH ≥3.0μIU/Ml (P = 0.03). This difference remained significant after adjustment for thyroid autoimmunity as well as age (P = 0.02).

CONCLUSIONS

Even after adjustment for thyroid autoimmunity and age, TSH <3.0μIU/mL in euthyroid infertility patients is associated with significantly better FOR (higher AMH) than TSH ≥3.0μIU/mL. This observation suggests a direct beneficial effect of lower TSH levels on follicular recruitment, and warrants investigations of thyroxin supplementation in infertile women with TSH levels ≥3.0μIU/mL in attempts to improve FOR.

[Thyroid function for infertile women during ovarian hyperstimulation as part of IVF]

OBJECTIVES

Optimal thyroid function is necessary for an effective fertility. Many authors have suggested that thyroid function has an impact on IVF outcome. Conversely, IVF has been suggested to induce changes in thyroid function. The aim of this study was to determine the nature and the timing of alterations in thyroid function, throughout controlled ovarian hyperstimulation, from the beginning of therapy to the day of triggering ovulation. And make a clarification of the current recommendations of the thyroid function during hormonal stimulation.

METHODS

Subjects were recruited from March 2013 to July 2013 at the Hospital of the University of Reims. The studied population consisted of 50 infertile patients who had undergone IVF/ICSI cycles. Thyroid axis exploration was realized before therapy and at every hormonal dosage during ovarian monitorage.

RESULTS

Prematuary fluctuations were observed without impact on pregnancy rate. We could detect potential hypothyroid women thanks to this dosage and define a connection between pregnancy rate and TSH with a threshold closer to 1mUI/L than 2,5mUI/L defined by the endocrine society.

CONCLUSIONS

The link between thyroid function, forecast of conception and pregnancy is well documented. Currently, there is no recommendation on the rate of TSH targets for the patients in medical assisted procreation.

Donor TSH level is associated with clinical pregnancy among oocyte donation cycles

PURPOSE

The purpose of the study is to evaluate the association between donor TSH level (independent of recipient TSH level) and recipient pregnancy outcome among fresh donor oocyte IVF cycles.

METHODS

This is a retrospective cohort study investigating 232 consecutive fresh donor-recipient cycles (200 total oocyte donors) at an academic medical center. Main outcome measures include clinical pregnancy and live birth.

RESULTS

Cycles were categorized into two groups based on donor TSH level (< 2.5 and ≥ 2.5 mIU/L). After controlling for multiple donor and recipient characteristics, the probability of clinical pregnancy was significantly lower among donors with TSH levels ≥2.5 mIU/L compared to those with TSH values <2.5 mIU/L (43.1 %, 95 % CI 28.5-58.9, versus 66.7 %, 95 % CI 58.6-73.9, respectively, p = 0.01). The difference in live birth rates between the two groups did not achieve statistical significance (43.1 %, 95 % CI 28.8-58.6, versus 58.0 %, 95 % CI 50.0-65.6, respectively, p = 0.09).

CONCLUSIONS

Donor TSH level, independent of recipient TSH level, is associated with recipient clinical pregnancy. These findings suggest that thyroid function may impact the likelihood of pregnancy at the level of the oocyte.

Assessment of ovarian reserve in euthyroid adolescents with Hashimoto thyroiditis

AIM

We aimed to investigate the ovarian function and reserve in euthyroid adolescents (TSH < 2.5 mIU/L) diagnosed with Hashimoto thyroiditis (HT).

METHODS

This case-control study included 30 adolescent girls (mean age 15.1 ± 1.4 years) newly diagnosed as HT with presence of high thyroid antibodies with gland heterogeneity in ultrasound and age-matched 30 healthy female subjects. Anti-ovarian antibody (AOAb), LH/FSH ratio, estradiol, anti-mullerian hormone (AMH), inhibin-B, total testosterone, antral follicle count, ovarian volumes and uterine length were measured. The clinical, laboratory, and ultrasound data of the HT and control groups were compared.

RESULTS

There were no significant differences between the girls with HT and healthy controls in relation to LH/FSH ratio, estradiol and inhibin-B levels. AOAb (p = 0.02), AMH (p = 0.007) and total testosterone levels were higher in HT group than the control group (p = 0.03). AOAb level was found to be positively correlated with LH/FSH ratio (p = 0.03), AMH (p = 0.01) and inhibin-B (p < 0.001) in HT group.

CONCLUSION

This study demonstrated that the adolescent girls diagnosed with autoimmune thyroiditis had normal ovarian reserve based on measurements of AMH, inhibin B, FSH, LH/FSH ratio, estradiol and antral follicle counts.

The impact of thyroid function and thyroid autoimmunity on embryo quality in women with low functional ovarian reserve: a case-control study

BACKGROUND

Women with hyper-and hypothyroidism are at increased risk for infertility and adverse pregnancy outcomes. Whether in women considered euthyroid thyroid function (TSH values) and thyroid autoimmunity (thyroid antibodies) influence in vitro fertilization (IVF) cycle outcome has, however, remained controversial. Any such effect should be easily visible in women with low functional ovarian reserve (LFOR) and thus small oocyte and embryo numbers.

METHODS

We evaluated the relationship between TSH levels and embryo quality in euthyroid women with LFOR undergoing IVF. Mean age for the study population was 39.9±4.6 years. Embryo quality was assessed in 431 embryos from 98 first IVF cycles according to TSH levels (with cut-off 2.5μIU/mL), and to presence versus absence of thyroid autoantibodies.

RESULTS

Mean Anti Mullerian hormone (AMH) was 0.8±0.8 ng/mL and mean TSH was 1.8±0.9 μIU/mL. Comparable embryo quality was observed in women with TSH≤ and >2.5μIU/mL. TPO antibodies significantly affected embryo quality in women with low-normal TSH levels (P=0.045). In women with high-normal TSH levels, increasing TSH had a negative impact on embryo quality (P=0.027). A trend towards impaired embryo quality with TPO antibodies was also observed in these patients (p=0.057).

CONCLUSIONS

TPO antibodies affect embryo quality in euthyroid women with low-normal TSH≤2.5 μIU/mL. In women with high-normal TSH levels, increasing TSH levels, and possibly TPO antibodies, appear to impair embryo quality. These results suggest that the negative impact of thyroid autoimmunity becomes apparent, once thyroid hormone function is optimized.

The role of magnesium and thyroid function in early pregnancy after in-vitro fertilization (IVF): New aspects in endocrine physiology

Background

The initiation of a pregnancy is a process that requires adequate energetic support. Recent observations at our Institution suggest a central role of magnesium in this situation. The aim of this study was to evaluate magnesium, zinc, selenium and thyroid function as well as anti-Müllerian hormone in early pregnancy following in-vitro fertilization as compared to spontaneous successful pregnancies.

Results

A successful outcome of pregnancy after IVF treatment was associated with 2 parameters: higher levels of anti-Müllerian hormone as well as higher levels of magnesium in the pre-stimulation blood sample. These two parameters, however, showed no correlation. Spontaneous pregnancies as well as pregnancies after IVF show a fall of magnesium levels at 2–3 weeks of gestation. This drop of magnesium concentration is larger following IVF as compared to spontaneous pregnancies. Parallel to these changes TSH levels showed an increase in early IVF-pregnancy. At this time point we also observed a positive correlation between fT4 and TSH. This was not observed in spontaneous pregnancies. Thyroid antibodies showed no correlation to outcomes.

Conclusions

In connection with the initiation of pregnancy following ovarian stimulation dynamic changes of magnesium and TSH levels can be observed. A positive correlation was found between fT4 and TSH in IVF pregnancies. In spontaneous pregnancies smaller increases of TSH levels are related to higher magnesium levels.

General significance

We propose that magnesium plays a role in early pregnancy as well as in pregnancy success independently from anti-Müllerian hormone. Neither thyroid hormones nor thyroid antibodies were related to outcome.

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Lack of correlation of thyroid function parameters to IVF outcome

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Significant drop of magnesium levels in early pregnancy after IVF

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Positive correlation between fT4 and TSH levels in early pregnancy following IVF

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Higher anti-Müllerian hormone levels are associated to successful IVF pregnancies.

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Higher magnesium levels are associated to successful IVF pregnancies.

Thyroxine treatment may be useful for subclinical hypothyroidism in patients with female infertility

Infertile women sometimes associated with subclinical hypothyroidism (SCH). The guidelines of the American Endocrine Society, and American Association of Clinical Endocrinologists and American Thyroid Association recommend treatment with thyroxine (T4) for patients with SCH who want to have children. We examined 69 female infertile patients with SCH and the effects of levothyroxine (l-T4) therapy on pregnancy rates and pregnancy outcomes were observed. Fifty-eight (84.1%) patients successfully conceived during the T4 treatment period (Group A), although 17 patients (29.3%) had miscarriage afterward. The remaining 11 patients continued to be infertile (Group B). The median TSH value in Group A before the T4 treatment was 5.46 μIU/mL (range 3.1-13.3) and this significantly decreased to 1.25 μIU/mL (range 0.02-3.75) during the treatment (p<0.001). The estimated duration of infertility before the T4 treatment was 2.8±1.7 years and the duration until pregnancy after the treatment was significantly shorter at 0.9±0.9 years (p<0.001). Shortening of the infertile period after the T4 therapy was observed not only in patients who were treated with assisted reproductive technology (ART) but also in patients who conceived spontaneously in Group A. Administered T4 dose was 54.3±14.2 μg before pregnancy and 68.5±22.8 μg during pregnancy (p<0.001). Anti-thyroid autoantibodies were identified in 42.0% of all patients and no significant difference was observed in positivity between Group A and Group B. High successful pregnancy rate and shorter duration of infertility until pregnancy after T4 treatment strongly suggest that T4 enhanced fertility in infertile patients with SCH.

IGF1R signaling is necessary for FSH-induced activation of AKT and differentiation of human Cumulus granulosa cells

CONTEXT

FSH is routinely administered to in vitro fertilization patients to induce follicle maturation. During this process, granulosa cells differentiate and acquire specific functional characteristics that are required to coordinate ovulation and oocyte maturation.

OBJECTIVE

The objective of the study was to gain insight into the molecular mechanisms regulating human granulosa cell differentiation. Design, Setting, Patients, and Interventions: Cumulus and mural granulosa cells were isolated from the follicular aspirates of in vitro fertilization patients and analyzed immediately or cultured in serum-free media in the presence of FSH, IGFs, or an inhibitor of type I IGF receptor (IGF1R) activity.

MAIN OUTCOME

We quantified the mRNA and protein levels of steroidogenic enzymes, components of the IGF system, and gonadotropin receptors; measured 17β-estradiol levels; and examined the activation of intracellular signaling pathways to assess the granulosa cell differentiation as well as the FSH and IGF actions in both cumulus and mural cells.

RESULTS

In freshly isolated cells, LH receptor (Lhr) and steroidogenic acute regulator (Star) were expressed at lower levels in cumulus than mural cells, whereas FSH receptor (Fshr) and anti-Müllerian hormone (Amh) were expressed at higher levels in cumulus than mural cells. In vitro, the expression of Igf2, the differentiation markers Lhr, Star, and Cyp19a1 (aromatase) as well as 17β-estradiol production remained low in untreated cumulus cells but increased significantly after FSH treatment. Strikingly, this stimulatory effect of FSH was abolished by the inhibition of IGF1R activity. FSH-induced activation of v-akt murine thymoma viral oncogene homolog 3 (AKT) required IGF1R activity, and overexpression of constitutively active AKT rescued the induction of differentiation markers and 17β-estradiol production by FSH in the presence of the IGF1R inhibitor.

CONCLUSIONS

The cumulus cell response to FSH resembles the differentiation of preantral to preovulatory granulosa cells. This differentiation program requires IGF1R activity and subsequent AKT activation.

Molecular basis of thyrotropin and thyroid hormone action during implantation and early development

BACKGROUND

Implantation and early embryo development are finely regulated processes in which several molecules are involved. Evidence that thyroid hormones (TH: T4 and T3) might be part of this machinery is emerging. An increased demand for TH occurs during gestation, and any alteration in maternal thyroid physiology has significant implications for both maternal and fetal health. Not only overt but also subclinical hypothyroidism is associated with infertility as well as with obstetric complications, including disruptions and disorders of pregnancy, labor, delivery, and troubles in early neonatal life.

METHODS

We searched the PubMed and Google Scholar databases for articles related to TH action on ovary, endometrium, trophoblast maturation and embryo implantation. In addition, articles on the regulation of TH activity at cellular level have been reviewed. The findings are hereby summarized and critically discussed.

RESULTS

TH have been shown to influence endometrial, ovarian and placental physiology. TH receptors (TR) and thyrotropin (thyroid-stimulating hormone: TSH) receptors (TSHR) are widely expressed in the feto-maternal unit during implantation, and both the endometrium and the trophoblast might be influenced by TH either directly or through TH effects on the synthesis and activity of implantation-mediating molecules. Interestingly, due to the multiplicity of mechanisms involved in TH action (e.g. differential expression of TR isoforms, heterodimeric receptor partners, interacting cellular proteins, and regulating enzymes), the TH concentration in blood is not always predictive of their cellular availability and activity at both genomic and nongenomic level.

CONCLUSIONS

In addition to the known role of TH on the hormonal milieu of the ovarian follicle cycle, which is essential for a woman's fertility, evidence is emerging on the importance of TH signaling during implantation and early pregnancy. Based on recent observations, a local action of TH on female reproductive organs and the embryo during implantation appears to be crucial for a successful pregnancy. Furthermore, an imbalance in the spatio-temporal expression of factors involved in TH activity might induce early arrest of pregnancy in women considered as euthyroid, based on their hormonal blood concentration. In conclusion, alterations of the highly regulated local activity of TH may play a crucial, previously underestimated, role in early pregnancy and pregnancy loss. Further studies elucidating this topic should be encouraged.

The impact of thyroid function on intrauterine insemination outcome--a retrospective analysis

BACKGROUND

Hashimoto's thyroiditis is the most common endocrinopathy in premenopausal women, and is associated with various gynecological problems, including recurrent miscarriage and unexplained infertility. A possible influence of Hashimoto's thyroiditis on the success of intrauterine insemination seems likely, but has not been evaluated as yet. Therefore, the aim of our study was to retrospectively analyze the impact on intrauterine insemination outcome of thyroid function and markers suggestive for Hashimoto's thyroiditis.

METHODS

Retrospective cohort study in a tertiary care center of 540 women who underwent Intrauterine Insemination. The clinical pregnancy rate was the main outcome parameters. The following possible influencing factors were tested: thyroid-stimulating hormone (TSH); thyroid autoantibodies; age; body mass index; type of sterility (primary/secondary); parity; male factor; presence of PCO syndrome; ovulation induction; ovarian stimulation; and current thyroid medication.

RESULTS

The overall clinical pregnancy rate was 6.9% (37/540). Age, thyroid hormone supplementation for thyroid-stimulating hormone (TSH) levels>2.5 micro-IU/ml, and ovulation induction with HCG were significantly predictive in the multivariate analysis (p<0.05) as influencing factors for the pregnancy rate after intrauterine insemination.

CONCLUSIONS

Women undergoing intrauterine insemination seem to benefit from a strict thyroid hormone supplementation regimen in order to achieve lower TSH levels.

The effects of maternal thyroid hormone function on early pregnancy

PURPOSE OF REVIEW

It is unclear whether pregnancy outcomes are impacted by nonovert thyroid disease, and whether detection and treatment of abnormalities improve outcomes. Consequently, there is an ongoing debate regarding universal thyroid screening in pregnancy. A lack of solid evidence has prompted researchers to evaluate the role of screening and to examine pregnancy outcomes in women with thyroid dysfunction. In addition, as IVF has developed into a commonly used procedure, its impact on thyroid function has also been investigated. The most current literature on these topics will be summarized in this review.

RECENT FINDINGS

The multiple societies that have published guidelines on thyroid disease in pregnancy have developed different recommendations, with none definitively advocating for universal screening at this time. However, recent studies examining the role of screening have supported it from an economic and prevalence standpoint. Despite this, evidence has failed to consistently demonstrate that treatment of nonovert thyroid disorders improves maternal and fetal outcomes. Recent research does suggest that close monitoring for and treatment of thyroid dysfunction is warranted in women undergoing IVF.

SUMMARY

Further research must be performed to determine whether treatment of nonovert thyroid disease during pregnancy impacts outcomes. Concrete evidence will likely influence the universal screening debate.

In vitro fertilization outcomes in treated hypothyroidism

BACKGROUND

Levothyroxine has been shown to enhance pregnancy outcomes in women with hypothyroidism requiring in vitro fertilization (IVF). However, the precise magnitude of these benefits remains to be determined. In particular, it has yet to be clarified whether levothyroxine may fully overcome the detrimental effects of hypothyroidism or, conversely, whether affected women remain at reduced prognosis for pregnancy outcomes.

METHODS

Patients who underwent IVF-intracytoplasmic sperm injection (ICSI) over a 3-year period were reviewed. Cases were deemed eligible if they were diagnosed with clinical or subclinical hypothyroidism and were receiving levothyroxine. Controls were two subsequently age-matched euthyroid women for every case. Both cases and controls were selected only if serum thyrotropin was ≤2.5 mIU/L.

RESULTS

In total, 137 women with treated hypothyroidism and 274 controls were included. Baseline characteristics of the two study groups were similar with the exception of body mass index, which was slightly higher among the cases (22.9±3.9 vs. 21.9±3.3 kg/m2, p=0.013). Most IVF-ICSI cycle outcome variables were also similar, with the exception of a higher rate of cancellation for poor response (3.6% vs. 0.7%, p=0.04), a longer duration of stimulation (10.9±2.2 vs. 10.1±2.0 days, p=0.001), a higher proportion of women failing to obtain viable embryos (17% vs. 7%, p=0.006), and a lower fertilization rate (75% vs. 86%, p=0.017) among cases. Conversely, the clinical pregnancy rate per started cycle, the implantation rate, and the live birth rate per started cycle did not differ; they were 36% and 34% (p=0.93), 28% and 22% (p=0.11), and 30% and 27% (p=0.50) in cases and controls, respectively. Subgroup analyses comparing women with (n=79) and without (n=58) thyroid autoimmunity and comparing women who were diagnosed with overt hypothyroidism (n=70) or subclinical hypothyroidism (n=67) failed to identify relevant differences.

CONCLUSIONS

In our population, IVF-ICSI outcome was not significantly hampered in women with adequately treated hypothyroidism. The magnitude of the detected differences in cycle outcome was mild, and we failed to document any differences for the most relevant outcomes, i.e., pregnancy rate, implantation rate, and delivery rate. In conclusion, adequate levothyroxine treatment maintaining thyrotropin serum levels below 2.5 mIU/L may overcome the detrimental effects of hypothyroidism.

Endometrial polyps in women affected by levothyroxine-treated hypothyroidism--histological features, immunohistochemical findings, and possible explanation of etiopathogenic mechanism: a pilot study

The aim of the study was to investigate the possible overexpression of estrogen (ERs) and progesterone (PRs) receptors both in EPs glandular and stromal cells in postmenopausal women with levothyroxine-treated hypothyroidism in comparison to EPs detected in women with physiological thyroid hormone levels. During the study period (January-February 2013) 22 patients were eligible (12 treated, 10 controls). The two groups were homogenous for general, EPs sonographic and hysteroscopic features. None of the cases of atypia was found. Immunohistochemistry showed that the two groups were similar for ERs and PRs intensity rates in EPs glandular cells despite a trend of ERs percentage expression more than 60% in 2/3 of treated patients versus 1/3 of controls. In stromal EPs components, ERs intensity was high positive in 10 (83,3%) treated cases while it was high positive in 1 control (10%). Percentage of ERs stromal expression showed a different trend between the two groups despite a borderline statistical significance. Our hypothesis is based on a possible double action of hypothyroidism and thyroxine intake: the subclinical TSH increased levels and its possible circadian oscillation could stimulate the endometrial TSHRs (increasing type 2 DIO activity); the circulating levels of exogenous thyroxine could be locally metabolized in active form by type 2 DIO stimulating ERs.

Levothyroxine treatment and pregnancy outcome in women with subclinical hypothyroidism undergoing assisted reproduction technologies: systematic review and meta-analysis of RCTs

BACKGROUND Previous meta-analyses of observational data indicate that pregnant women with subclinical hypothyroidism have an increased risk of adverse pregnancy outcome. Potential benefits of levothyroxine (LT4) supplementation remain unclear, and no systematic review or meta-analysis of trial findings is available in a setting of assisted reproduction technologies (ART). METHODS Relevant trials published until August 2012 were identified by searching MEDLINE, EMBASE, Web of Knowledge, the Cochrane Controlled Trials Register databases and bibliographies of retrieved publications without language restrictions. RESULTS From 630 articles retrieved, we included three trials with data on 220 patients. One of these three trials stated 'live delivery' as outcome. LT4 treatment resulted in a significantly higher delivery rate, with a pooled relative risk (RR) of 2.76 (95% confidence limits 1.20-6.44; P = 0.018; I(2) = 70%), a pooled absolute risk difference (ARD) of 36.3% (3.5-69.0%: P = 0.030) and a summary number needed to treat (NNT) of 3 (1-28) in favour of LT4 supplementation. LT4 treatment significantly lowered miscarriage rate with a pooled RR of 0.45 (0.24-0.82; P = 0.010; I(2) = 26%), a pooled ARD of -31.3% (-48.2 to -14.5%: P < 0.001) and a summary NNT of 3 (2-7) in favour of LT4 supplementation. LT4 treatment had no effect on clinical pregnancy (RR 1.75; 0.90-3.38; P = 0.098; I(2) = 82%). In an ART setting, no data are available on the effects of LT4 supplementation on premature delivery, arterial hypertension, placental abruption or pre-eclampsia. CONCLUSIONS Our meta-analyses provide evidence that LT4 supplementation should be recommended to improve clinical pregnancy outcome in women with subclinical hypothyroidism and/or thyroid autoimmunity undergoing ART. Further research is needed to determine pregnancy outcome after close monitoring of thyroid function to maintain thyroid-stimulating hormone and free T4 levels within the trimester-specific reference ranges for pregnancy.