Serum prolactin and TSH in an in vitro fertilization population: is there a link between fertilization and thyroid function?

Levothyroxine for a high-normal TSH in unexplained infertility

OBJECTIVE

Unexplained infertility affects nearly one-third of infertile couples. Women with unexplained infertility are more likely to have a high-normal thyroid-stimulating hormone level (TSH: 2.5-5 mIU/L) compared to women with severe male factor infertility. Practice guidelines vary on whether treatment should be initiated for TSH levels >2.5 mIU/L in women attempting conception because the effects of treating a high-normal TSH level with levothyroxine are not known. We evaluated conception and live birth rates in women with unexplained infertility and high-normal TSH levels.

DESIGN, PATIENTS AND MEASUREMENTS

Retrospective study including 96 women evaluated for unexplained infertility at a large academic medical centre between 1 January 2000 and 30 June 2017 with high-normal TSH (TSH: 2.5-5 mIU/L and within the normal range of the assay) who were prescribed (n = 31) or not prescribed (n = 65) levothyroxine. Conception and live birth rates were assessed.

RESULTS

The conception rate in the levothyroxine group was 100% compared to 90% in the untreated group (p = .086 unadjusted; p < .05 adjusted for age; p = .370 adjusted for TSH; p = .287 adjusted for age and TSH). The live birth rate was lower in the levothyroxine group (63%) compared to the untreated group (84%) (p = .05 unadjusted; p = .094 adjusted for age; p = .035 adjusted for TSH; p = .057 adjusted for age and TSH).

CONCLUSIONS

Women with unexplained infertility and high-normal TSH levels treated with levothyroxine had a higher rate of conception but lower live birth rate compared to untreated women, with the limitation of a small sample size. These findings assert the need for prospective, randomized studies to determine whether treatment with levothyroxine in women with unexplained infertility and high-normal TSH is beneficial.

Correlation of Serum Prolactin and Thyroid Stimulating Hormone Concentration in Infertile Women: A Systematic Review and Meta-Analysis

Infertility affects millions of people of reproductive age worldwide. Thyroid hormones and prolactin (PRL) affect reproduction and pregnancy; therefore, these two hormones influence fertility. This systematic review and meta-analysis aimed to summarise the strength of the correlation between serum PRL and thyroid stimulating hormone (TSH) in infertile women and to explore selected factors influencing the correlation. We conducted a systematic search of online databases (PubMed, Scopus, ScienceDirect, SAGE and Google Scholar) from inception until March 2021 and a manual search of the bibliographies of the included studies to identify relevant publications. The original research paper describing the correlation between PRL and TSH in reproductive-age women with infertility (primary and secondary) was included. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Analytical Cross-Sectional Studies. A random effect model was used to estimate the pooled correlations of PRL and TSH, followed by an assessment of heterogeneity and a sensitivity analysis. From a total of 822 relevant articles identified, 11 were eligible and included in this systematic review and meta-analysis. The random effect pooled correlation estimates between PRL and TSH was 0.431 (95% CI: 0.251, 0.582), with substantial heterogeneity between the included studies (I2 = 80%, τ2 = 0.067, P < 0.001). No significant publication bias was observed. Study region, types of infertility, sample size and year of the study did not influence the correlation estimates. Our results highlighted a significant positive moderate correlation between serum PRL and serum TSH in infertile women.

Impact of Endocrine Disorders on IVF Outcomes: Results from a Large, Single-Centre, Prospective Study

Endocrine disorders negatively influence the ovarian function, and increasing incidence of endocrine diseases with age may have further negative effects on pregnancy rate. Prospective cohort study of 231 consecutively enrolled patients underwent IVF treatment. In patients with known endocrine disorders, the laboratory parameters were corrected before IVF treatment. One hundred sixty one patients (69.7%) had at least one known and treated endocrine disorder (study group), and 70 patients were endocrine negative (control group). Endocrine disorders diagnosed were thyroid disorders (32.5%), diminished ovarian reserve (23.8%), insulin resistance (22.5%), PCOS (15.2%), hyperprolactinaemia (13.4%), obesity (12.1%), hypogonadotropic hypogonadism (0.8%) and congenital adrenal hyperplasia (0.2%). Before the IVF treatment, systematic endocrine laboratory examinations were performed in all patients. Higher age, BMI and FSH were found in the study group, while AMH level was lower. There were no differences in LH, E2, prolactin, TSH, FT3, FT4, TT, DHEAS, androstendione, 17-OHP and SHBG level between the study and control groups. The study group had higher baseline glucose, baseline insulin, 120-min glucose and 120-min insulin level after oral glucose tolerance test. With no difference in the IVF cycles performed, pregnancy rate was lower in the study group (61.43% vs. 34.16%; p = 0.003), and this difference (p = 0.0151) remained in age-corrected rates, as well. The analyses were also performed in individual endocrinology groups. The prevalence of endocrine disorders is high in females participating in IVF programs, and they are often accompanying each other. Even after proper correction, the presence of the endocrine disorder negatively influences the pregnancy rate in IVF treatment.

Subclinical hypothyroidism and antithyroid autoantibodies in women with subfertility or recurrent pregnancy loss: Scientific Impact Paper No. 70 June 2022: Scientific Impact Paper No. 70 June 2022

The thyroid is a gland located in the neck and is important for many processes in the body. Problems with the thyroid gland are common in women of reproductive age. It is essential to have a normal working thyroid gland in order to achieve a successful pregnancy. One of the most common problems with the thyroid is underactivity (known as hypothyroidism). An early, mild form of an underactive thyroid is called subclinical hypothyroidism. Often people with this condition do not have any symptoms. Another common problem is thyroid autoimmunity. Here, the immune system attacks the thyroid gland, sometimes leading to the development of abnormal thyroid function. This can be diagnosed by the presence of proteins in the bloodstream called antibodies. Mild thyroid problems and the presence of high levels of thyroid antibodies have been linked to miscarriage and premature birth. There is debate in medicine about whether there should be routine testing of thyroid function both in the general population and in individuals who are trying for a baby. In addition, the strategies used to manage certain thyroid problems are questioned. Discussions around testing and subsequent management particularly relate to women with a history of subfertility or repeated miscarriages. This Scientific Impact Paper provides information on thyroid testing and the management of mild thyroid problems and thyroid antibodies in women with a history of subfertility or recurrent miscarriages, using the latest evidence and guidelines. It concludes that there may be a role for treating these women with thyroxine tablets (the hormone produced by the thyroid gland) when subclinical hypothyroidism is present, and gives guidance on the cut-off levels for treatment.

Evaluating thyroid function in pregnant women

Thyroid hormones are primarily responsible for regulating the basal metabolic rate but also make important contributions to reproductive function and fetal development. Both hyper- and hypothyroidism in pregnancy have been associated with increased risks of complications that include preeclampsia and low birth weight, among others. Furthermore, thyroid hormone deficiency in the developing fetus results in neurodevelopmental delay. As the fetus is exclusively reliant on maternal thyroid hormone for most of the first trimester and requires continued maternal supply until birth, identifying maternal thyroid dysfunction is critically important. However, evaluating thyroid function in pregnancy is challenging because of the many physiological changes that affect concentrations of thyroid-related analytes. Increasing plasma human chorionic gonadotropin (hCG) concentrations in the second half of the first trimester elicit a corresponding transient decrease in thyroid-stimulating hormone (TSH), and continually increasing estradiol concentrations throughout pregnancy cause substantial increases in thyroxine-binding globulin (TBG) and total thyroxine (T4) relative to the nonpregnant state. Lastly, free T4 concentrations gradually decrease with increasing gestational age. For these reasons, it is essential to interpret thyroid function test results in the context of trimester-specific reference intervals to avoid misclassification of thyroid status. This review summarizes the effects of thyroid dysfunction prior to conception and during pregnancy and describes considerations for the laboratory assessment of thyroid function in pregnant women.

The prevalence of hyperprolactinaemia in subfertile ovulatory women and its impact on fertility treatment outcome

Subtle hyperprolactinaemia is not an uncommon finding in ovulatory subfertile women. The objective of this study is to evaluate the prevalence of hyperprolactinaemia in subfertile ovulatory and oligo-anovulatory women, and to determine if hyperprolactinaemia influences fertility treatment outcome. All women (n = 1010) who attended the fertility clinic of a UK tertiary hospital during 2015-2019 were included. Out of 804 eligible women analysed, 575 women (71.5%) were ovulatory and 229 (28.5%) were oligo-anovulatory. Prevalence of hyperprolactinaemia was higher in the ovulatory group than in the oligo-anovulatory group (26.8% vs. 14.4%; OR: 2.2; 95% confidence interval (CI): 1.4-3.2). On sub-group analysis, the prevalence of mild, moderate and severe hyperprolactinaemia was 23.0%, 3.7% and 0.2% in ovulatory women and 11.8%, 1.7% and 0.9% in oligo-anovulatory women. Mild hyperprolactinaemia was found to be more prevalent in the ovulatory group (OR: 2.2; 95%CI: 1.4-3.5). Ongoing pregnancy/livebirth rates were similar between hyperprolactinaemic and normoprolactinaemic women (42.8% vs. 46.7%). Hyperprolactinaemia did not have an impact on ongoing pregnancy/livebirth rates in both ovulatory and oligo-anovulatory women (OR:0.8; 95%CI: 0.5-1.1; OR: 1.2; 95%CI: 0.6-2.5, respectively). Hyperprolactinaemia is prevalent among ovulatory women, although most had mildly raised clinically insignificant levels. Elevated prolactin levels in ovulatory women do not seem to impact on pregnancy outcome. Impact StatementWhat is already known on this subject? Prolactin has been linked to ovulation and fertility. Prolactin testing is not generally recommended for subfertile women with regular menstrual cycles, which is a surrogate marker of ovulation. However, some clinicians, particularly in the general practice, still perform prolactin test as part of baseline endocrine profile.What do the results of this study add? Prevalence of hyperprolactinaemia in subfertile ovulatory women was 26.8% (154/575), of which 86% (132/154) were mild. Further, the livebirth/ongoing pregnancy rates were similar between hyperprolactinaemic and normoprolactinaemic women. Prolactin being a sensitive hormone, responsive to even minimal stress and its high levels not influencing clinical pregnancy outcome, prolactin measurement is not needed in women having regular menstrual cycles.What are the implications of these findings for clinical practice and/or further research? Hyperprolactinaemia was not uncommon in ovulatory women, although most had mildly elevated levels. Hyperprolactinaemia did not have any impact on fertility treatment outcome. Serum prolactin should not be tested in ovulating women, as mild elevations are commonly present and have no clinical significance.

Relationship between maternal serum thyroid-stimulating hormone and in vitro fertilisation-conceived pregnancy outcomes

Background:

Thyroid dysfunction impairs female fertility and pregnancy outcome. Optimal preconception and gestational TSH level is still debatable in IVF-conceived pregnancies.

Aims:

To explore the relationships of IVF success and pregnancy outcomes with maternal serum levels of TSH (at both preconception and 12-week IVF-conceived pregnancy). Also, to confirm or refute the recommended TSH level ≤2.5μIU/mL.

Study Setting and Design:

Retrospective cohort.

Material and Methods:

158 IVF-conceived pregnant women and 117 age-matched controls non-pregnant (≤39years, BMI 18.5-38kg/m2) were recruited. Preconception and 12-week IVF-conceived pregnancy serum samples were analysed for reproductive hormones, fasting glucose, insulin and TSH levels. Data of pregnant women at 28 weeks for GDM screening (75-gram OGTT) and up until delivery were included.

Statistical Analysis:

Binary logistic regression used to predict association between preconception TSH levels and IVF success, and pregnancy outcomes. Association of delta change of hormones was determined with linear regression. Significance level P≤0.05 with 95% confidence interval (CI).

Results:

Overall, median (IQR) age was 32(6)years, BMI 25.4(6.9)kg/m2, HbA1c 5.2(0.52)% and TSH 1.82(1.4)μIU/mL. There was no significant association between preconception TSH level and IVF success rate. During the first trimester of IVF-conceived pregnancy, delta change in TSH level was associated with that of progesterone (P=0.03). 12-week gestation TSH level did not predict adverse pregnancy outcomes (i.e. onset of GDM, delivery type and premature delivery); but a higher TSH level predicted earlier delivery in weeks. There was a higher risk of delivery by caesarean section when TSH>2.5μIU/mL.

Conclusion:

Variation of maternal TSH within normal range (0.4-4.0μIU/mL) at preconception and 12-week gestation has no predictive effect on IVF success and pregnancy outcomes in IVF-pregnancy. Our data provide no support for a recommended preconception TSH level ≤2.5μIU/mL in IVF-conceived pregnancy, but rather promote a preconception TSH level within normal range.

More Live Births in Primary Subfertile Intracytoplasmic Sperm Injection-Treated Women with High Normal TSH Levels

OBJECTIVES

The aim of this study was to analyze the fertility outcome in intracytoplasmic sperm injection (ICSI)-treated women across normal range thyroid-stimulating hormone (TSH) levels. Published results are inconclusive about optimal TSH levels and fertility.

DESIGN

This is a retrospective cohort study in 752 ICSI-treated women with predominantly severe male factor subfertility, starting treatment between the first of January 2008 and the first of March 2012 with a follow-up until 2014. Participants/Materials, Setting, Methods: Women aged 22-45 years with TSH 0.3-4.5 mIU/L without thyroid hormone substitution were included in Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands, an iodine-sufficient area. Demographic and baseline characteristics were compared between groups of patients based on TSH, using one-way ANOVA, Kruskal-Wallis ANOVA, and χ2 test. The patient was the unit of analysis: all cumulative cycles per patient were analyzed up to and including the first ongoing pregnancy. The primary outcome was a cumulative live birth rate. Clinical pregnancy rate, pregnancy loss, and ongoing pregnancy rate were secondary outcomes. The χ2 test and logistic regression were used to compare interquartile groups while adjusting for confounders. Logistic regression was used with the natural logarithm of TSH as a continuous predictor. Primary and secondary subfertile women were analyzed separately.

RESULTS

Analysis of the total cohort (n = 752) showed no difference in fertility outcomes across the normal TSH range. The cumulative live birth rate for the 4 groups of primary subfertile women (n = 455) was 76% in the upper TSH quartile compared to 56%, 60%, and 59% in the lower TSH quartiles.

LIMITATIONS

Levels of thyroxine and presence of thyroid autoimmunity were not measured in this retrospective cohort study.

CONCLUSIONS

The observation that a higher live birth rate was found in primary subfertile ICSI-treated women with high but allegedly normal TSH levels contributes to the hypothesis that in certain subfertile women in addition to a male factor, female factors such as subtle hypothyroidism and/or thyroid autoimmunity may play a role in keeping them from conception, which can be overcome by the process of ICSI.

Thyroxine Replacement for Subfertile Females With Subclinical Hypothyroidism and Autoimmune Thyroiditis: A Systematic Review

The second most prevalent endocrine condition affecting women of reproductive age is thyroid disease. The difference between an increased thyroid-stimulating hormone (TSH) concentration and a normal free thyroxine hormone level is used to identify subclinical hypothyroidism. Thyroid autoantibodies, independent of thyroid hormone levels, are used to diagnose autoimmune thyroid disease (ATD). Thyroxine can help infertile women with these two types of thyroid illnesses have better birth outcomes during fertility treatment. We performed a systematic review using PubMed (Medline) as a major database and some other sources EMBASE, the Cochrane Library, Web of Science, Scopus, and Science Direct. We concentrated on four studies, including 806 patients. Our goal is to investigate the efficacy and risks of levothyroxine therapy in infertile women who are receiving fertility treatments and have subclinical hypothyroidism or adequate thyroid function as well as thyroid autoimmunity (euthyroid autoimmune thyroid disorder). Thyroid activity in hypothyroid women should be tracked at pregnancy confirmation and closely monitored during the pregnancy. Early in pregnancy, the dosage of levothyroxine (LT4) can be raised. To ensure optimum TSH levels during breastfeeding, we recommend that patients who are followed in the primary sector have their LT4 dose increased by their general practitioner before their first referral to an endocrinological outpatient clinic. It's important to pay more attention to and track pregnant women with hypothyroidism, who consider pregnancy, to get the best results. LT4 therapy can help subfertile women with subclinical hypothyroidism who are having in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) since it improves embryo growth, implantation rate, and live birth rate.

The Effect of Radioactive Iodine Therapy on Ovarian Function and Fertility in Female Thyroid Cancer Patients: A Systematic Review and Meta-Analysis

Introduction: Thyroid cancer is one of the most common carcinomas diagnosed in adolescents and young adults, with a rapidly rising incidence for the past three decades. Surgery is the standard treatment for patients with differentiated thyroid carcinoma (DTC), and when indicated, followed by radioactive iodine (RAI) treatment. The aim of this study was to evaluate the possible effects of RAI therapy on ovarian function and fertility in women. Methods: The PubMed, Embase, and Web of Science databases were systematically searched up to January 2020. In addition, a meta-analyses were performed for anti-Mullerian hormone (AMH) levels after RAI, comparison of AMH levels prior and 1 year after RAI, and pregnancy rates in patient with thyroid cancer receiving RAI compared with patients with thyroid cancer who did not receive RAI. Results: A total of 36 studies were eligible for full-text screening and 22 studies were included. The majority of the studies had a retrospective design. Menstrual irregularities were present in the first year after RAI in 12% and up to 31% of the patients. Approximately 8-16% of the patients experienced amenorrhea in the first year after RAI. Women who received RAI treatment (median dose 3700 MBq [range 1110-40,700 MBq]); had menopause at a slightly younger age compared with women who did not receive RAI treatment, 49.5 and 51 years, respectively (p < 0.001). Pooled AMH of the seven studies reporting AMH concentrations after RAI was 1.79 ng/mL. Of these, four studies reported AMH concentrations prior and 1 year after RAI. The mean difference was 1.50 ng/mL, which was significant. Finally, meta-analysis showed that patients undergoing RAI were not at a decreased risk of becoming pregnant. Conclusions: Most of the studies indicate that RAI therapy for DTC is not associated with a long-term decrease in pregnancy rates although meta-analyses show a significant decrease in AMH levels after RAI therapy. Prospective studies are needed to confirm these results. We recommend counseling patients about the possible effects of ¹³¹I and incorporate today's knowledge in multidisciplinary counseling.

2021 European Thyroid Association Guideline on Thyroid Disorders prior to and during Assisted Reproduction

Severe thyroid dysfunction may lead to menstrual disorders and subfertility. Fertility problems may persist even after restoring normal thyroid function, and then an assisted reproductive technology (ART) may be a solution. Prior to an ART treatment, ovarian stimulation is performed, leading to high oestradiol levels, which may lead to hypothyroidism in women with thyroid autoimmunity (TAI), necessitating levothyroxine (LT4) supplements before pregnancy. Moreover, women with the polycystic ovarian syndrome and idiopathic subfertility have a higher prevalence of TAI. Women with hypothyroidism treated with LT4 prior to ART should have a serum TSH level <2.5 mIU/L. Subfertile women with hyperthyroidism planning an ART procedure should be informed of the increased risk of maternal and foetal complications, and euthyroidism should be restored and maintained for several months prior to an ART treatment. Fertilisation rates and embryo quality may be impaired in women with TSH >4.0 mIU/L and improved with LT4 therapy. In meta-analyses that mainly included women with TSH levels >4.0 mIU/L, LT4 treatment increased live birth rates, but that was not the case in 2 recent interventional studies in euthyroid women with TAI. The importance of the increased use of intracytoplasmic sperm injection as a type of ART on pregnancy outcomes in women with TAI deserves more investigation. For all of the above reasons, women of subfertile couples should be screened routinely for the presence of thyroid disorders.

Common endocrine disorders associated with the polycystic ovary syndrome

Introduction

Screening of polycystic ovary syndrome (PCOS) women for hypothyroidism and hyperprolactinemia was suggested, because the undiagnosed hypothyroidism and hyperprolactinemia can aggravate the PCOS symptoms.

Aim of the study

To determine whether the insulin resistance (IR), hypothyroidism, and hyperprolactinemia are common endocrine disorders associated with the PCOS.

Material and methods

One hundred and twenty PCOS women were compared to 120 non-PCOS controls in this study. Participants' day 2-3 hormonal profile and insulin resistance (IR) using the fasting glucose and fasting insulin were evaluated. Collected data were analyzed to determine whether the IR, hypothyroidism, and hyperprolactinemia are common endocrine disorders associated with the PCOS.

Results

TSH and prolactin were significantly high in PCOS women (6.4 ±4.2 and 934 ±102.3, respectively) than controls (3.5 ±3.3 and 445 ±77.5 mIU/ml, respectively) (p = 0.004 and 0.001, respectively). The PCOS women had significantly high relative risk of IR (RR 3.0 (95% CI: 1.9-4.7) p < 0.0001), hypothyroidism (RR 3.4; 95% CI: 1.7-6.9) (p = 0.0005), and hyperprolactinaemia (RR 3.15; 95% CI: 1.8-5.6) (p = 0.0001) than controls. The PCOS women had higher odds of IR (OR 4.8; 95% CI: 2.6-8.8) (p < 0.0001), hypothyroidism (OR 4.29; 95% CI: 1.9-9.4) (p = 0.0003), and hyperprolactinaemia (OR 4.27; 95% CI: 2.1-8.5) (p < 0.0001) than controls.

Conclusions

TSH and prolactin were significantly high in studied PCOS women, and 47.5% of the studied PCOS women had IR. The PCOS women had significantly higher odds and relative risks of IR, hypothyroidism, and hyperprolactinemia than controls. IR, hypothyroidism, and hyperprolactinemia are common endocrine disorders associated with PCOS.

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.

Thyroid Hormones and Functional Ovarian Reserve: Systemic vs. Peripheral Dysfunctions

Thyroid hormones (THs) exert pleiotropic effects in different mammalian organs, including gonads. Genetic and non-genetic factors, such as ageing and environmental stressors (e.g., low-iodine intake, exposure to endocrine disruptors, etc.), can alter T4/T3 synthesis by the thyroid. In any case, peripheral T3, controlled by tissue-specific enzymes (deiodinases), receptors and transporters, ensures organ homeostasis. Conflicting reports suggest that both hypothyroidism and hyperthyroidism, assessed by mean of circulating T4, T3 and Thyroid-Stimulating Hormone (TSH), could affect the functionality of the ovarian reserve determining infertility. The relationship between ovarian T3 level and functional ovarian reserve (FOR) is poorly understood despite that the modifications of local T3 metabolism and signalling have been associated with dysfunctions of several organs. Here, we will summarize the current knowledge on the role of TH signalling and its crosstalk with other pathways in controlling the physiological and premature ovarian ageing and, finally, in preserving FOR. We will consider separately the reports describing the effects of circulating and local THs on the ovarian health to elucidate their role in ovarian dysfunctions.

Effect of levothyroxine supplementation on pregnancy loss and preterm birth in women with subclinical hypothyroidism and thyroid autoimmunity: a systematic review and meta-analysis

BACKGROUND

Subclinical hypothyroidism (SCH) and thyroid autoimmunity (TAI) are associated with adverse pregnancy outcomes such as pregnancy loss and preterm birth. However, the ability of levothyroxine (LT4) supplementation to attenuate the risks of these outcomes remains controversial.

OBJECTIVE AND RATIONALE

This systematic review and meta-analysis was conducted to determine the effect of LT4 supplementation on pregnancy loss rate (PLR) and preterm birth rate (PBR) among pregnant women with SCH and TAI.

SEARCH METHODS

A systematic literature search of the PubMed, EMBASE, Web of Science and Cochrane Controlled Trials Register databases and Clinicaltrials.gov was performed to identify all relevant English studies published up to April 2018. The following terms were used for the search: [subclinical hypothyroidism OR thyroid autoimmunity OR thyroperoxidase antibody (TPO-Ab) OR thyroglobulin antibodies (Tg-Ab)] AND (levothyroxine OR euthyrox) AND [pregnancy outcome OR miscarriage OR abortion OR pregnancy loss OR preterm birth OR premature delivery OR early labo(u)r]. The reference lists of the relevant publications were also manually searched for related studies. Published manuscripts were included if they reported data on pregnancy loss, preterm birth or both. We separately analysed the pooled effects of LT4 supplementation on PLR and PBR in women with SCH and TAI.

OUTCOMES

Overall, 13 eligible studies including 7970 women were included in the meta-analysis. Eight and five of these studies were randomized controlled trials (RCTs) and retrospective studies, respectively. The pooled results indicated that LT4 supplementation significantly decreased the PLR [relative risk (RR) = 0.56, 95% confidence interval (CI): 0.42-0.75, I2 = 1%, 12 studies] and PBR (RR = 0.68, 95% CI: 0.51-0.91, I2 = 21%, eight studies) in women with SCH and/or TAI. We further found that LT4 supplementation significantly decreased the risk of pregnancy loss (RR = 0.43, 95% CI: 0.26-0.72, P = 0.001, I2 = 0%) but not of preterm birth (RR = 0.67, 95% CI: 0.41-1.12, P = 0.13, I2 = 0%) in women with SCH. Furthermore, LT4 supplementation significantly decreased the risks of both pregnancy loss (RR = 0.63, 95% CI: 0.45-0.89, P = 0.009, I2 = 0%) and preterm birth (RR = 0.68 95% CI: 0.48-0.98, P = 0.04, I2 = 46%) in women with TAI. These results were consistent when only RCTs were included in the analysis. Further, in women with SCH, LT4 supplementation reduced the risk of pregnancy loss in pregnancies achieved by assisted reproduction (RR = 0.27, 95% CI: 0.14-0.52, P < 0.001, I2 = 14%) but not in naturally conceived pregnancies (RR = 0.60, 95% CI: 0.28-1.30, P = 0.13, I2 = 0%). By contrast, in women with TAI, LT4 supplementation reduced the risks of both pregnancy loss (RR = 0.61, 95% CI: 0.39-0.96, P = 0.03, I2 = 0%) and preterm birth (RR = 0.49, 95% CI: 0.30-0.79, P = 0.003, I2 = 0%) in naturally conceived pregnancies but not in pregnancies achieved by assisted reproduction (RR = 0.68, 95% CI: 0.40-1.15, P = 0.15, I2 = 0% for pregnancy loss and RR = 1.20, 95% CI: 0.68-2.13, P = 0.53, I2 not applicable for preterm birth).

WIDER IMPLICATIONS

This meta-analysis confirmed the beneficial effects of LT4 supplementation, namely the reduced risks of pregnancy loss and preterm birth, among pregnant women with SCH and/or TAI. The different effects of LT4 supplementation on naturally conceived pregnancies and pregnancies achieved by assisted reproduction in women with SCH and/or TAI suggest that these women should be managed separately. Due to the limited number of studies included in this meta-analysis, especially in the subgroup analysis, further large RCTs and fundamental studies are warranted to confirm the conclusions and better clarify the molecular mechanism underlying these associations.

Role of hypothyroidism and associated pathways in pregnancy and infertility: Clinical insights

Thyroid disorders are the most common endocrine problems in women. In most of the cases, thyroid can lead to infertility or miscarriages. The etiology of infertility is multifactorial with thyroid disorders as the most common presenting factor, hypothyroidism in particular. Infertility in women can lead to emotional and psychological stress. The prevalence of hypothyroidism during pregnancy is estimated to be 0.3%–0.5%. Hypothyroidism and hyperthyroidism can result in menstrual irregularities and anovulatory cycles, thus affecting the fertility. There is a significant high prolactin (PRL) level in infertile women with hypothyroidism when compared to euthyroid patients, indicating the relation between hypothyroidism and hyperprolactinemia. The amount of thyrotropin releasing hormone (TRH) from the hypothalamus is markedly increased by inhibition of pyroglutamyl peptidase II, the enzyme catalyzing TRH. The increased TRH in hypothyroidism causes increased thyroid-stimulating hormone and PRL secretion by pituitary, leading to infertility and galactorrhea. In recent years, a neuropeptide called kisspeptin, encoded by Kiss1 gene, a potent stimulus for GnRH secretion, has been recognized, which suggests a future direction of treatment with kisspeptin and benefits the fertility induction among hyperprolactinemic infertile patients. Untreated hypothyroidism during pregnancy can lead to subfertility, fetal deaths, premature deliveries, and abortions. Therefore, women planning for pregnancy and infertile women should be assessed for thyroid hormones and serum PRL.

Predictive serum markers for unexplained infertility in child-bearing aged women

PROBLEM

Unexplained infertility (UI) represents about 25%-40% of all infertility and is a formidable obstacle for successful pregnancy for child-bearing aged women. However, up to now, there is no reliable method to predict this condition with high accuracy, thereby hindering early management of this condition.

METHOD OF STUDY

Our prospective study consists of 84 child-bearing aged women that were clinically diagnosed UI. Forty-four matched healthy fertility (HF) women were served as controls. We examined the profiles of 25 hormones and cytokines that were likely related to pathogeneses and molecular pathways involved in UI with the technique of protein array. The samples were randomly stratified 7:3 into a training set and a testing set. We used the SMOTEboost model with 10 serum proteins in a clinical verification study to identify UI cases.

RESULTS

The predictor had an area under the receiver operating characteristic curve (AUC) of 0.788 with 24 serum protein features. The predictive performance in terms of AUC of the model with the top 10 important serum proteins in the clinical verification study to classify UI cases was 0.809. Three most significantly differentially expressed proteins (DEPs) were prolactin, monocyte chemotactic protein-1 (MCP-1), and leptin.

CONCLUSION

Examination of serum-based protein profile changes could help to identify child-bearing aged women at risk of UI. This would enable early detection and facilitate development of clinical strategies to treat UI and guide their planned parenthood. It may also give clues to pathogeneses of the condition of test subjects.

Weight management merits attention in women with infertility: a cross-sectional study on the association of anthropometric indices with hormonal imbalance in a Ghanaian population

OBJECTIVE

This study determined the association of anthropometric indices with hormonal imbalance among infertile women in a Ghanaian population.

RESULTS

Follicle stimulating hormone (FSH) levels (18.47 vs. 8.67, p-value = 0.002), and luteinizing hormone (LH) (12.43 vs. 8.01, p-value = 0.044) were higher in women with primary infertility compared with women presenting with secondary infertility. Waist circumference (WC) and waist-to-height ratio (WHtR) showed significant negative partial correlation with prolactin in both primary and secondary infertile women. Also a significant negative partial correlation was observed between BMI and prolactin in secondary infertile women only. Waist-to-hip ratio (WHR) showed a positive association with LH in both primary and secondary infertility. WHR also showed significant positive correlation to LH/FSH ratio in secondary infertility whereas body adiposity index (BAI) showed a negative correlation to LH/FSH ratio. In a correlation analysis of anthropometric measures with hormonal profile and causes of infertility as a fixed factor, the association between anthropometric indices and fertility hormones was largely dependent on the underlying causes of infertility.

Thyroxine replacement for subfertile women with euthyroid autoimmune thyroid disease or subclinical hypothyroidism

BACKGROUND

Thyroid disease is the second most common endocrine disorder affecting women of reproductive age. Subclinical hypothyroidism is diagnosed by an elevated thyroid-stimulating hormone concentration with a normal concentration of free thyroxine hormone. Autoimmune thyroid disease (ATD) is diagnosed by the presence of thyroid autoantibodies, regardless of thyroid hormone levels. Thyroxine may be a useful treatment for subfertile women with these two specific types of thyroid disease for improving pregnancy outcomes during assisted reproduction.

OBJECTIVES

To evaluate the efficacy and harms of levothyroxine replacement in subfertile women with subclinical hypothyroidism or with normal thyroid function and thyroid autoimmunity (euthyroid autoimmune thyroid disease, or euthyroid ATD) undergoing assisted reproduction.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility (CGF) Group specialised register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL and two trials registers together with reference checking and contact with study authors and experts in the field to identify studies. We searched for all published and unpublished randomised controlled trials (RCTs) comparing thyroxine with no treatment or placebo, without language restrictions, from inception to 8 April 2019, and in consultation with the Cochrane CGF Information Specialist.

SELECTION CRITERIA

We included women undergoing assisted reproduction treatment, meaning both in vitro fertilisation and intracytoplasmic sperm injection, with a history of subfertility and with subclinical hypothyroidism or with euthyroid ATD. We excluded women with a previously known clinical hypothyroidism or already taking thyroxine or tri-iodothyronine. RCTs compared thyroxine (levothyroxine) with either placebo or no treatment.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary review outcomes were live birth and adverse events of thyroxine; our secondary outcomes were clinical pregnancy, multiple pregnancy and miscarriage.

MAIN RESULTS

The review included four studies with 820 women. The included studies were of overall low risk of bias. Using GRADE methodology, we assessed the quality of evidence for the primary outcomes of this review to be very low- to low-quality evidence. Evidence was downgraded for imprecision as it was based on single, small trials with wide confidence intervals (CI). We were able to include data from three of the four included studies.In one study of women with both subclinical hypothyroidism and positive or negative anti-TPO antibodies (autoimmune disease), the evidence suggested that thyroxine replacement may have improved live birth rate (RR 2.13, 95% CI 1.07 to 4.21; 1 RCT, n = 64; low-quality evidence) and it may have led to similar miscarriage rates (RR 0.11, 95% CI 0.01 to 1.98; 1 RCT, n = 64; low-quality evidence). The evidence suggested that women with both subclinical hypothyroidism and positive or negative anti-TPO antibodies would have a 25% chance of a live birth with placebo or no treatment, and that the chance of a live birth in these women using thyroxine would be between 27% and 100%.In women with normal thyroid function and thyroid autoimmunity (euthyroid ATD), treatment with thyroxine replacement compared with placebo or no treatment may have led to similar live birth rates (risk ratio (RR) 1.04, 95% CI 0.83 to 1.29; 2 RCTs, number of participants (n) = 686; I2 = 46%; low-quality evidence) and miscarriage rates (RR 0.83, 95% CI 0.47 to 1.46, 2 RCTs, n = 686, I2 = 0%; low-quality evidence). The evidence suggested that women with normal thyroid function and thyroid autoimmunity would have a 31% chance of a live birth with placebo or no treatment, and that the chance of a live birth in these women using thyroxine would be between 26% and 40%.Adverse events were rarely reported. One RCT reported 0/32 in the thyroxine replacement group and 1/32 preterm births in the control group in women diagnosed with subclinical hypothyroidism and positive or negative anti-TPO antibodies. One RCT reported 21/300 preterm births in the thyroxine replacement group and 19/300 preterm births in the control group in women diagnosed with positive anti-TPO antibodies. None of the RCTs reported on other maternal pregnancy complications, foetal complications or adverse effects of thyroxine.

AUTHORS' CONCLUSIONS

We could draw no clear conclusions in this systematic review due to the very low to low quality of the evidence reported.

Prolactin and thyroid stimulating hormone affecting the pattern of LH/FSH secretion in patients with polycystic ovary syndrome: A hospital-based study from North East India

Introduction:

Polycystic ovary syndrome (PCOS) is one of the most important endocrinal diseases in reproductive age group, clinically manifested by hyperandrogenism and anovulation and different other metabolic disturbances that may have important implications for long-term health.

Aim and Objective:

The aim of this study was to determine the incidence of abnormal luteinizing hormone/follicle-stimulating hormone (LH/FSH) ratio in women with polycystic ovary and to assess the influence of prolactin and thyroid-stimulating hormone (TSH) in the elevated LH/FSH ratio.

Study Design:

Retrospective observational study.

Materials and Methods:

Eighty-five women in reproductive age diagnosed with PCOS between June 2012 to June 2014 at the Department of Obstetrics and Gynecology in a tertiary care hospital were selected for the study. Serum LH and FSH levels were determined and LH/FHS ratio (normal range ≤2) calculated in the study subjects. They underwent a detailed clinical, hormonal, and metabolic evaluation, which was performed between the second and third days of a natural or induced menstrual period.

Results:

Elevated LH/FSH ratio was found in 60 women (70.58%). Normal gonadotropin ratio was detected in 25 women (29.41%). Statistically significant differences in serum TSH levels were noted between groups with normal and elevated LH/FSH ratio. However, no statistically significant difference was noted in other endocrine parameters. Further analysis revealed a slight negative correlation of TSH with prolactin in the study subjects of PCOS with an ‘r’ value of − 0.3.

Conclusions:

LH/FSH ratio is one of the characteristic attribute of PCOS women. In the present study, this abnormality was detected in 70% of patients. Hypothyroidism was a common endocrinal abnormality and prolactin was inversely correlated to TSH levels in PCOS patients.

Preconceptional thyrotropin level in euthyroid women is inversely associated with the live birth rate in first in vitro fertilization cycle

INTRODUCTION

Thyroid disorders have been associated with adverse reproductive outcome. Whether the preconceptional level of thyrotropin (TSH) in euthyroid women impacts on in vitro fertilization (IVF) outcome has been debated. This study reports the outcome of first IVF cycle in euthyroid women in relation to TSH level.

MATERIAL AND METHODS

A retrospective study was conducted in women referred for fertility treatment in the period 1 January 2012 until 31 March 2014. Among the exclusion criteria were thyroid medication at referral and comorbidities. TSH was measured as part of the fertility workup, and women were followed until pregnancy loss or live birth. Outcome as well as patient characteristics were prospectively collected from a treatment database.

RESULTS

A total of 623 euthyroid women underwent their first IVF cycle. The live birth rate was 27.0% (n = 168). Comparing women with a preconceptional TSH level above vs below 2.5 mIU/L, we found lower odds for clinical pregnancy (adjusted odds ratio [aOR] 0.52; 95% CI 0.29-0.95), and lower odds for live birth (aOR 0.53; 95% CI 0.29-0.99).

CONCLUSIONS

A preconceptional TSH level >2.5 mIU/L was associated with lower odds for clinical pregnancy and live birth in euthyroid healthy women undergoing first IVF cycle.

Relationship between Hypothyroidism and Endometrial Cancer

Thyroid dysfunction is involved in several types of carcinoma. Hypothyroidism is one of the most common medical morbidities among patients with endometrial cancer; however, the related mechanism is unclear. Among the risk factors related to endometrial cancer, hypothyroidism interacts with metabolic syndrome, polycystic ovarian syndrome and infertility or directly acts on the endometrium itself, which may influence the development and progression of endometrial cancer. We summarize recent studies on the relationship between hypothyroidism and endometrial cancer and its risk factors to provide references for basic research as well as for clinical treatment and prognostic evaluation.

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.

Type 1 diabetes impairs female fertility even before it is diagnosed

AIMS

The aim of this study was to assess the fertility rate in Taiwanese women before and after a diagnosis of type 1 diabetes. The potential risk factors which may have influenced fertility were also investigated.

METHODS

We conducted this retrospective, nationwide, population-based, matched cohort study using data from the Taiwan National Health Insurance Research Database. The diabetic group (n = 1191) included women with type 1 diabetes aged between 16 and 30 years in 2000. The non-diabetic group (n = 4764) was matched by sex, gender, income, and urbanization. The endpoints, including live births, abortions, and fertility, were tracked until the end of 2013. Poisson regression was used to assess incidence rate ratios (IRRs). We also analyzed the influence of autoimmune thyroid disease, diabetic ketoacidosis, diabetic complications, and daily insulin dose on the endpoints.

RESULTS

The diabetic group had a lower rate of live births (IRR 0.67 [95% CI 0.62-0.73]) than the non-diabetic group, and it was even lower when combined with hyperthyroidism (IRR 0.54 [0.39-0.74]). There were also fewer live births before a diagnosis of diabetes than after a diagnosis of diabetes (IRR 0.58 [0.52-0.65] vs. 0.80 [0.71-0.90]). Diabetic ketoacidosis and a higher daily insulin dose were strongly associated with abortion. Diabetic complications significantly reduced the number of live births.

CONCLUSIONS

Type 1 diabetes compromises female fertility, even before it is diagnosed. Associated hyperthyroidism further reduces fertility. Blood glucose and thyroid function surveillance in infertile females may allow for an early diagnosis of type 1 diabetes and associated thyroid disease.

Nanosized titanium dioxide-induced premature ovarian failure is associated with abnormalities in serum parameters in female mice

Background

Exposure to titanium dioxide nanoparticles (TiO₂ NPs) that are widely used in food, medicine, sunscreen products and cosmetics is reported to cause ovarian damage and lower fertility in animals. However, the potential effects of TiO₂ NPs application on premature ovarian failure (POF) have rarely been evaluated to date.

Methods

In this study, female mice were continuously exposed to TiO₂ NPs at doses of 2.5, 5 or 10 mg/kg via gavage instillation for 30 days, and investigated the serum hormones and autoimmunity markers associated with POF.

Results

Exposure to TiO₂ NPs resulted in POF, reductions in the levels of estradiol, progesterone and inhibin B and increases in luteinizing hormone, follicle-stimulating hormone, follicle-stimulating hormone/luteinizing hormone ratio, anti-Müllerian hormone, thyroid-stimulating hormone, free triiodothyronine, free tetraiodothyronine, anti-nuclear antibody and anti-thyroid peroxidase antibody levels in serum.

Conclusion

Exposure to TiO₂ NPs induced POF triggered by alterations in hormones and autoimmunity markers. Our findings highlight the necessity for significant caution in handling and usage of TiO₂ NPs by female consumers.

Evaluation of ovarian reserve in women with overt or subclinical hypothyroidism

INTRODUCTION

Thyroid dysfunction is among the most common autoimmune disorders in women of reproductive age. Previous studies have shown the association between autoimmune thyroid disease (AITD) and infertility. Anti-Müllerian hormone (AMH) is secreted by granulosa cells and is a useful marker for assessment of ovarian reserve. In the present study, we sought to evaluate the ovarian reserves of women with autoimmune thyroid disorder by measurement of AMH values.

MATERIAL AND METHODS

This prospective study included women with newly diagnosed AITD aged between 20 and 40 years. Patients were divided into three groups: subclinical hypothyroidism (SCH, n = 21), overt hypothyroidism (OH, n = 21) and controls (CG, n = 32). Study parameters included serum free T4, free T3, thyroid-stimulating hormone, anti-thyroglobulin, anti-thyroid peroxidase antibodies, follicle-stimulating hormone, luteinizing hormone, estradiol and AMH concentrations measured in the early follicular phase. Antral follicle count (AFC) was assessed with ultrasound. Body mass index (BMI) and waist circumference of the patients were noted.

RESULTS

No significant difference was found among SCH, OH and CG in regard to ovarian reserves measured by AMH values (p = 0.19) and AFC (p = 0.80). A significant negative correlation was found between AMH and BMI (r = -0.382, p = 0.001). Anti-Müllerian hormone and waist circumference (r = -0.330, p = 0.004) were also negatively correlated.

CONCLUSIONS

Although AMH values were not significantly different among groups, AMH values were lower in OH and SCH patients, indicating a possible need for close monitoring of these patients.

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.

Higher TSH Levels Within the Normal Range Are Associated With Unexplained Infertility

CONTEXT

Unexplained infertility (UI), defined as the inability to conceive after 12 months of unprotected intercourse with no diagnosed cause, affects 10% to 30% of infertile couples. An improved understanding of the mechanisms underlying UI could lead to less invasive and less costly treatment strategies. Abnormalities in thyroid function and hyperprolactinemia are well-known causes of infertility, but whether thyrotropin (TSH) and prolactin levels within the normal range are associated with UI is unknown.

OBJECTIVE

To compare TSH and prolactin levels in women with UI and women with a normal fertility evaluation except for an azoospermic or severely oligospermic male partner.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study including women evaluated at a large academic health system between 1 January 2000 and 31 December 2012 with normal TSH (levels within the normal range of the assay and ≤5 mIU/L) and normal prolactin levels (≤20 ng/mL) and either UI (n = 187) or no other cause of infertility other than an azoospermic or severely oligospermic partner (n = 52).

MAIN OUTCOME MEASURES

TSH and prolactin.

RESULTS

Women with UI had significantly higher TSH levels than controls [UI: TSH 1.95 mIU/L, interquartile range: (1.54, 2.61); severe male factor: TSH 1.66 mIU/L, interquartile range: (1.25, 2.17); P = 0.003]. This finding remained significant after we controlled for age, body mass index, and smoking status. Nearly twice as many women with UI (26.9%) had a TSH ≥2.5 mIU/L compared with controls (13.5%; P < 0.05). Prolactin levels did not differ between the groups.

CONCLUSIONS

Women with UI have higher TSH levels compared with a control population. More studies are necessary to determine whether treatment of high-normal TSH levels decreases time to conception in couples with UI.

Subclinical Hypothyroidism: Frequency, clinical presentations and treatment indications

Objective:

To determine the frequency, modes of clinical presentation and indications for replacement therapy in a cohort of patients with subclinical hypothyroidism (SCH).

Methods:

This study was conducted at the Endocrine and Diabetes Unit of Jinnah Postgraduate Medical Centre from September 2007 – October 2015. This was a retrospective chart analysis of prospectively collected data in whichthe medical records of 4448 patients who had presented to the Endocrine Clinic from 2007 to 2015 were reviewed. A total of 2760 (62.05%) patients were diagnosed withthyroid disorders, whereas 260 (9.42%) patients had SCH. The SCH patients were between the age of 12 to 70 years; TSH was> 4mIU/l with normal levels of FT3 and FT4. Patients were enrolled using a predesigned structured proforma. Those having chronic systemic diseases were excluded from this study. SPSS 13 was used to evaluate the data.

Results:

Femalepatients comprised93.8% (244 patients) of those with SCH, whereas only 6.2% (16 patients) were male. Common presenting symptoms were, lethargy in 146 patients (56.2%); increase in weight in 102 patients (39.2%) and menstrual irregularities in 90 patients (34.6%). TSH level of < 10mIU/l (4 - 10) was seen in 177 patients (68.1%) and 83 patients (31.9%) had TSH ≥ 10mU/l. Thyroxine was given to 183 (70.4%) of these patients. Common treatment indications were TSH of ≥ 10, which was seen in 83 patients (31.9%), subfertility in 32 patients (12.3%), troublesome symptoms suggestive of hypothyroidism in 31 patients (11.9%) and high titers of antibodies in 23 patients (8.8%).

Conclusion:

SCH is frequently seen in our population, with most patients complaining of lethargy. The most common treatment indications were a TSH ≥ 10mIU/l, whereas troublesome symptoms of hypothyroidism and subfertility were the common treatment indications in patients who had a TSH of < 10mIU/l.

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.

Thyroid dysfunction and subfertility

The thyroid hormones act on nearly every cell in the body. Moreover, the thyroid gland continuously interacts with the ovaries, and the thyroid hormones are involved in almost all phases of reproduction. Thyroid dysfunctions are relatively common among women of reproductive age, and can affect fertility in various ways, resulting in anovulatory cycles, high prolactin levels, and sex hormone imbalances. Undiagnosed and untreated thyroid disease can be a cause of subfertility. Subclinical hypothyroidism (SCH), also known as mild thyroid failure, is diagnosed when peripheral thyroid hormone levels are within the normal reference laboratory range, but serum thyroid-stimulating hormone levels are mildly elevated. Thyroid autoimmunity (TAI) is characterized by the presence of anti-thyroid antibodies, which include anti-thyroperoxidase and anti-thyroglobulin antibodies. SCH and TAI may remain latent, asymptomatic, or even undiagnosed for an extended period. It has also been demonstrated that controlled ovarian hyperstimulation has a significant impact on thyroid function, particularly in women with TAI. In the current review, we describe the interactions between thyroid dysfunctions and subfertility, as well as the proper work-up and management of thyroid dysfunctions in subfertile women.

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.

Elevated serum thyroid-stimulating hormone is associated with decreased anti-Müllerian hormone in infertile women of reproductive age

PURPOSE

Thyroid dysfunction and autoimmune thyroiditis are associated with fertility in women of reproductive age. Anti-Müllerian hormone (AMH), a known biomarker of ovarian function, may be affected by impaired thyroid function; however, the relationship between AMH and thyroid hormone has not been elucidated.

METHODS

In this case-control study, to identify the impact of thyroid hormone on ovarian reserve, we recruited 67 consecutive Japanese infertile patients and 27 normal fertile women aged 30-39 years without impact factors on thyroid and ovarian functions between 2012 and 2013. We assessed patient age, BMI and AMH, prolactin, TSH and FT4 levels of all study participations as independent variables. To evaluate the relationship between AMH and thyroid hormone, we matched patients by age and body mass index as confounding factors using 1:1 matching for statistical analysis of healthy fertile women and infertile patients and obtained 23 pairs. Then, independent variables were subjected to multiple regression analysis.

RESULTS

Multiple regression analysis showed that both thyroid-stimulating hormone (TSH) levels and patient age were negatively correlated with AMH levels in infertile patients (patient age and TSH: standardized partial regression coefficient (β), -0.534 and -0.361; p = 0.003 and 0.036, respectively), but not in normal fertile women.

CONCLUSIONS

AMH levels were inversely correlated with TSH levels in infertile women of reproductive age.

Live birth rates following in vitro fertilization in women with thyroid autoimmunity and/or subclinical hypothyroidism

OBJECTIVE

To investigate whether the live birth rate following in vitro fertilization (IVF) is affected by thyroid autoimmunity (TAI) and/or subclinical hypothyroidism in subfertile women.

DESIGN AND SETTING

Retrospective study in a university infertility clinic.

PATIENTS

A total of 627 women without past or current history of thyroid disorder undergoing their first IVF cycle.

INTERVENTION

Pre-IVF archived blood serum samples were tested for TAI and thyroid function tests.

MAIN OUTCOME MEASURE

Live birth rate.

RESULTS

The clinical pregnancy rate, live birth rate and miscarriage rate were similar among women with or without TAI and/or subclinical hypothyroidism using a TSH threshold 4·5 mIU/l. Thyroid autoantibody level did not affect these IVF outcomes.

CONCLUSION

The live birth rate and miscarriage rate of women with TAI and/or subclinical hypothyroidism following IVF were not impaired.

Impaired outcome of controlled ovarian hyperstimulation in women with thyroid autoimmune disease

BACKGROUND

Controlled ovarian hyperstimulation (COH) is a crucial step of assisted reproductive technology (ART). Thyroid dysfunction and autoimmune thyroid disease (ATD) may negatively affect the outcome of ART, but the underlying mechanisms are still poorly understood. Our aim was to evaluate the respective role of ATD and thyroid function, as assessed by serum thyrotropin (TSH), on the early outcome of COH.

METHODS

In total, 262 (202 ATD-negative and 60 ATD-positive) euthyroid subfertile women underwent ART. Before COH, serum follicle-stimulating hormone (FSH), luteinizing hormone, and estradiol (E2) were measured at cycle day 3, and progesterone at cycle day 21. At oocyte pickup and at embryo transfer, we evaluated the performance of recombinant FSH (r-FSH), as assessed by serum E2 concentration/total administered r-FSH units (E2/r-FSH) ratio and by oocyte quality.

RESULTS

At both oocyte pickup and embryo transfer, the performance of r-FSH was significantly poorer in ATD-positive than in ATD-negative women. In the ATD-positive group, women with a TSH <2.5 mIU/L displayed a higher serum E2 concentration at oocyte pickup, a higher E2/r-FSH ratio, and a greater number of mature metaphase II oocytes than women with a TSH >2.5 mIU/L. When ATD-positive women were divided into quartiles according to their serum TSH level, both the ovarian response to r-FSH and the number of mature metaphase II oocytes significantly increased from the lowest to the highest quartiles of serum TSH concentration.

CONCLUSIONS

ATD has a negative effect on the early outcome of COH, but this negative influence may be avoided with adequate levothyroxine therapy aimed at keeping TSH <2.5 mU/L. Thyroid antibodies and serum TSH should be checked in any woman undergoing ART.

Effect of antithyroid antibodies on ICSI outcome in antiphospholipid antibody-negative euthyroid women

Antithyroid antibodies (ATA) are found in 5-15% of women at reproductive age and are not necessarily accompanied with thyroid dysfunction. ATA are associated with adverse effects such as spontaneous miscarriage, recurrent miscarriages, preterm delivery and maternal post-partum thyroiditis in women with normal thyroid hormone concentrations. The role of ATA on the outcome of IVF cycles remains to be investigated. This study evaluated the impact of ATA on the outcome of intracytoplasmic sperm injection (ICSI)-embryo transfer cycles in euthyroid women. A total of 253 women undergoing ICSI-embryo transfer cycles were prospectively enrolled in this study. Women positive for at least one of the thyroid antibodies, with normal thyroid-stimulating hormone (TSH) and free T4 concentrations and negative for anticardiolipin antibodies and lupus anticoagulant were included. ICSI was performed for fertilization in all cycles. Of 253 women, 219 were ATA negative and 34 ATA positive. Implantation rates (19.1% versus 18.4%), miscarriage rates (9.0% versus 8.3%) and ongoing pregnancy rates (37.0% versus 32.4%) did not differ significantly between the ATA-positive group and the ATA-negative group, respectively. The presence of antithyroid antibodies in euthyroid and antiphospholipid antibody-negative women was not found to significantly affect the outcome of ICSI-embryo transfer cycles. Antithyroid antibodies (ATA) can interact with thyroid hormone receptors located on the human oocyte and impair the chance of fertilization and healthy pregnancy. They are found in 5-15% of women at reproductive age and are not necessarily accompanied with thyroid dysfunction. ATA have been reported to be associated with adverse effects such as spontaneous miscarriage, recurrent miscarriages, preterm delivery and maternal post-partum thyroiditis in women with normal thyroid hormone concentrations. The role of ATA on the outcome of IVF cycles remains to be investigated. The objective of our study was to evaluate the impact of ATA on the outcome of intracytoplasmic sperm injection (ICSI)-embryo transfer cycles in euthyroid women. A total of 253 women undergoing ICSI-embryo transfer cycles were prospectively enrolled in this study. Women with at least one of the thyroid antibodies positive and normal TSH and free T4 concentrations were included in the study. Since other immunological disorders might affect the results, antiphospholipid antibodies (APA), which are the markers of antiphospholipid antibody syndrome, were also screened in all women prior to study. Women with positive for APA were excluded in the final analysis. Of 253 women, 219 (86.6%) were ATA negative and 34 (13.4%) ATA positive. Implantation rates (19.1% versus 18.4%), biochemical pregnancy rates (9.2% versus 14.3%), miscarriage rates (9.0% versus 8.3%) and ongoing pregnancy rates (37.0% versus 32.4%) did not differ significantly between the ATA-positive group and the ATA-negative group, respectively. In conclusion, presence of antithyroid antibodies in euthyroid and antiphospholipid antibody-negative women does not affect the outcome of ICSI-embryo transfer cycles.

Predictive value of hormonal parameters for live birth in women with unexplained infertility and male infertility

BACKGROUND

Infertile women might get pregnant sometime after fertility treatment, but today, there is no prediction model on who will eventually have children. The objective of the present study was to characterize hormone levels in an arbitrary menstrual cycle in women with unexplained infertility and male infertility, and to determine the predictive value for long-term possibility of live birth.

METHODS

In this cross-sectional study, with 71 infertile women with diagnosis unexplained infertility and male infertility, blood samples were obtained during the proliferative and secretory phases of an arbitrary menstrual cycle. Serum concentrations of FSH, LH, AMH, inhibin B, estradiol, progesterone, PRL and TSH were determined. The predictive value of ovulation and hormonal analysis was determined by identifying the proportion of women with at least one live birth. Mann Whitney U test, chi2 test and Spearman's correlation were used for statistical analysis. A value of p < 0.05 was considered statistically significant.

RESULTS

There were no differences in hormone values and live birth rates between women with unexplained infertility and male infertility. The best sole predictors of live birth were age of the women, followed by ovulatory cycle, defined as serum progesterone concentration of greater than or equal to 32 nmol/L, and a serum TSH concentration of less than or equal to 2.5 mIU/L. Combining the age with the ovulatory cycle and serum TSH less than or equal to 2.5 mIU/L or serum AMH greater than or equal to 10 pmol/L the predictive value was close to 90%.

CONCLUSIONS

Age in combination with the presence of an ovulatory cycle and serum TSH or serum AMH is predictive for long-term live birth. The advantage of serum AMH compared with serum TSH is the very little variation throughout the menstrual cycle, which makes it a useful tool in infertility diagnosis.

Hyperprolactinaemia and its comparision with hypothyroidism in primary infertile women

AIM AND OBJECTIVE

To study the serum prolactin levels and the serum TSH in primary infertile females.

MATERIAL AND METHOD

In this study, we investigated thirty women who were diagnosed cases of primary infertility, who attended the Biochemistry Department, Sir JJ Group of Hospitals, Mumbai, India, for hormonal evaluations. Thirty fertile women with similar ages were enrolled as the controls. The status of the thyroid dysfunction and the levels of serum prolactin were reviewed in infertile women and in the controls. The serum Prolactin and the thyroid stimulating hormone levels were measured by using Siemens kits in IMMULITE 1000 chemiluminescence immunoassays.

RESULTS

In our study, the serum prolactin levels in the infertile group were found to be high as compared to those in the control group and they were highly significant (p<0.0001). The serum TSH levels in the infertile group were found to be high, as compared to those of control group and they were highly significant (p<0.0001).

CONCLUSION

There is a higher incidence of hyperprolactinaemia in infertile patients. There is also a greater propensity for thyroid disorders in infertile women than in the fertile ones. The incidence of hypothyroidism in the hyperprolactinaemic subjects in the study population was found to be highly significant than the normal controls.

Association of obesity with hormonal imbalance in infertility: a cross-sectional study in north Indian women

Hormones play an important role in the development and regulation of reproductive function and the menstrual cycle of women. Extremes of body weight tend to affect the homeostasis of the hypothalamo-pituitary-gonadal axis. This cross-sectional study was carried out in 113 women (57 with primary infertility and 56 with secondary infertility) in the age group 20-35 years, presenting for hormonal evaluation of infertility in a tertiary care hospital. After preliminary clinical evaluation, anthropometric indices (height, weight, BMI, waist circumference and waist hip ratio) were measured in all subjects. Fasting blood sample drawn on second/third day of menstrual cycle was analysed for serum luteinizing hormone, follicle stimulating hormone (FSH), prolactin and thyroid stimulating hormone (TSH). Serum FSH levels showed a significant positive correlation with indicators of central obesity (waist circumference and waist hip ratio in both the study groups). In primary infertility, significant positive correlation was also observed between serum FSH levels and other markers of obesity like body weight, hip circumference and BMI. In secondary infertility, serum prolactin and serum TSH levels demonstrated a significant positive correlation with body weight and BMI. Obesity is associated with hormonal derangements which are responsible for infertility. In overweight women with infertility, weight loss should be considered as a first line treatment.

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.

Secondhand tobacco smoke exposure is associated with prolactin but not thyroid stimulating hormone among nonsmoking women seeking in vitro fertilization

Prolactin (PRL) and thyroid stimulating hormone (TSH) serve important roles in the reproductive and other systems. Active smoking is associated with changes in PRL and TSH secretion, but the relationship between secondhand tobacco smoke (STS) exposure and these hormones is unclear. We measured PRL and TSH in serum as well as cotinine in follicular fluid (to estimate STS exposure) among 314 nonsmoking women undergoing in vitro fertilization treatment. We observed a significant increase in PRL concentrations (p=0.03) among STS-exposed nonsmokers compared to unexposed nonsmokers. There was no significant difference in TSH concentration (p>0.4) among those exposed to STS compared to those who were unexposed. STS exposure is associated with an increase in circulating PRL but not TSH levels. Future studies are needed to confirm our results, identify biological mechanisms involved, and better understand the potential clinical and public health implications.

Serum and follicular fluid concentrations of polybrominated diphenyl ethers and in-vitro fertilization outcome

There is evidence of endocrine disruption and reproductive effects in animals following exposure to certain PBDEs, but human studies are limited. The goal of this study was to investigate the use of serum and follicular fluid as biomarkers of exposure to PBDEs and to explore whether a relationship between PBDE exposure and early pregnancy loss exists. We measured 8 PBDE congeners in archived serum and ovarian follicular fluid samples from 65 women undergoing in-vitro fertilization (IVF). Logistic regression models were used to predict the odds of failed embryo implantation associated with higher levels of PBDEs among the women in the study. There were moderate Kendall's Tau-beta correlations between serum and follicular fluid concentrations of BDE 28, 47, 100 and 154 (T(β)=0.29-0.38, all p-values<0.005), but BDE 99 and 153 were not correlated between the two matrices (T(β)<0.2, p-values>0.05). Women with detectable concentrations of BDE 153 (39% had detectable levels) in follicular fluid had elevated odds of failed implantation compared with women who had non-detectable concentrations (adjusted OR=10.0; 95%CI: 1.9 to 52; p=0.006; adjusted by age and body mass index). These findings suggest that exposure to BDE 153 may be associated with failed embryo implantation. Due to our observation of only moderate correlations between matrices, serum PBDE concentrations may not be a good indicator of follicular fluid concentrations when studying early pregnancy endpoints in women undergoing IVF.

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

BACKGROUND

Untreated hypothyroidism can lead to ovulatory dysfunction resulting in oligo-amenorrhea. Treatment with levothyroxine can reverse such dysfunction and thus should improve fertility. The purpose of this retrospective study was to assess whether in vitro fertilization (IVF) pregnancy rates differ in levothyroxine-treated women with hypothyroidism compared to women without thyroid dysfunction/disorders.

METHODS

Treated hypothyroid and euthyroid women undergoing IVF at an academic IVF center were studied after Institutional Review Board approval. Women with hypothyroidism were treated with levothyroxine 0.025-0.15 mg/day for at least 3 months to maintain baseline thyrotropin (TSH) levels of 0.35-4.0 μU/mL prior to commencing IVF treatment (HYPO-Rx group). Causes of infertility were similar in both groups with the exception of male factor, which was more common in the HYPO-Rx group. The main outcomes studied were implantation rate, clinical pregnancy rate, clinical miscarriage rate, and live birth rate.

RESULTS

We reviewed the first IVF retrieval cycle performed on 240 women aged 37 years or less during the period January 2003 to December 2007. Women with treated hypothyroidism (n=21) had significantly less implantation, clinical pregnancy, and live birth rates than euthyroid women (n=219).

CONCLUSIONS

We conclude that, despite levothyroxine treatment, women with hypothyroidism have a significantly decreased chance of achieving a pregnancy following IVF compared to euthyroid patients. A larger prospective study is necessary to assess confounding variables, confirm these findings, and determine the optimal level of TSH prior to and during controlled ovarian hyperstimulation for IVF.