Thyrotropin-releasing hormone (TRH) and metoclopramide testing in infertile women

Correlation Analysis Between Ovarian Reserve and Thyroid Hormone Levels in Infertile Women of Reproductive Age

OBJECTIVE

To analyze the correlation between ovarian reserve and thyroid function in women with infertility.

METHODS

Retrospective analysis of the data of 496 infertility patients who visited the clinic between January 2019 and December 2020. According to the TSH level, it is grouped into <2.5 mIU/L, 2.5~4.0mIU/L and ≥4.0 mIU/L or according to the positive/negative thyroid autoimmune antibody. The relationship was assessed through the ovarian reserve, thyroid function, and anti-Müllerian hormone (AMH) levels in infertile patients. On the other hand, the patients are divided into groups according to age (≤29 years old, 30-34 years old and ≥35 years old), basic FSH (<10 IU/L and ≥10 IU/L), and AMH levels. The ovarian reserve was evaluated through the AMH and the antral follicle count (AFC).

RESULTS

The average age of the patients was 30.31 ± 4.50 years old, and the average AMH level was 5.13 ± 4.30 ng/mL. 3.63% (18/496) of patients had abnormal TSH levels (normal: 0.35-5.5 mIU/L), the positive rate of thyroid peroxidase antibody (TPOAb) was 14.52% (72/496), the positive rate of anti-thyroglobulin antibody (TgAb) was 16.94% (84/496), and the positive rate of TPOAb and TgAb was 10.48% (52/496). After grouping according to TSH level or thyroid autoimmune antibody positive/negative grouping, the analysis found that there was no statistical significance in age, AMH level and basic FSH level among the groups (P>0.05). There were no significant differences in the levels of TSH, FT3, and FT4 among different ages, AMH, and FSH levels (P>0.05).

CONCLUSION

There is no significant correlation between ovarian reserve and thyroid function in infertile women.

Association of Thyroid Profile and Prolactin Level in Patient with Secondary Amenorrhea

BACKGROUND

Amenorrhea is the absence of menstrual periods. It has multiple social consequences as it may leads to infertility. This case control study was conducted for determining the association of thyroid hormones with hyperprolactinemia in patient with amenorrhea.

METHODS

We investigated 50 women with diagnosed cases of secondary amenorrhoea, who attended UCMS hospital, for hormonal evaluations. Fifty two healthy women were taken as the controls. The thyroid dysfunction and serum prolactin level were reviewed in cases and in the controls.

RESULTS

Mean serum prolactin level was found to be significantly higher in the cases as compared to the controls. Mean serum fT3 and fT4 level in the hyperprolactinemic cases (mean = 2.67, SD = 1.04 pg/ml) and (mean = 1.38, SD = 0.51 ng/dl respectively) were slightly lower as compared to normoprolactinemic cases (mean = 3.21, SD = 1.86 pg/ml) and (mean = 1.73, SD = 1.37 ng/dl) respectively. Mean TSH of normoprolactinemic and hyperprolactinemic cases were comparable (P = 0.049). There was positive correlation between prolactin, BMI and TSH whereas negative correlation of prolactin was seen with fT3, fT4 and age. In hyperprolactainemic cases, prolactin was found to be negatively correlated with TSH (r = -0.155, P = 0.491) whereas prolactin was positively correlated with TSH (r = 0.296, P = 0.126) in normoprolactainemic cases.

CONCLUSIONS

Thus, hyperprolactinemia with thyroid dysfunction may be contributory hormonal factor in patient with amenorrhoea and as such, estimation of prolactin, fT3, fT4 and TSH should be included for diagnostic evaluation of amenorrhea.

Evaluation of serum prolactin level in patients of subclinical and overt hypothyroidism

BACKGROUND

Prolactin secretion is controlled by prolactin inhibitor factor that is secreted from hypothalamus; factors like vasoactive inhibitory peptide (VIP) and thyroid releasing hormone (TRH) lead to increase in prolactin secretion. Hyperprolactinemia is a common condition that can result from a number of causes including hypothyroidism. Objective of the study was to determine correlation between serum levels of prolactin and thyroid hormones in euthyroid, subclinical and overt hypothyroid cases.

MATERIALS AND METHODS

Consecutive patients presenting for various thyroid related problems were segregated into two groups subclinical and overt hypothyroidism according to their diagnosis based on history and clinical examination, laboratory reports, inclusion and exclusion criteria. Newly diagnosed 75 patients in each group were finally enrolled. Similar number of age and sex matched controls were selected. All subjects filled a predesigned questionnaire for the evaluation of hypothyroid symptoms. Thyroid profile for T3, T4 (total and free), TSH and prolactin were determined in all the subjects and analyzed.

RESULTS

Prolactin elevation was found in 16 patients (21.33 %) with overt hypothyroidism, and in six patients (8%) with subclinical hypothyroidism. The control group and subclinical hypothyroid patients exhibited no significant difference in terms of total and free T3, total and free T4. For TSH and prolactin on the other hand, a statistically significant elevation was found in patients with overt hypothyroidism when compared with subclinical hypothyroidism; and in patients with subclinical hypothyroidism when compared to the controls. A significant statistical difference was observed between the two groups of hypothyroid patients for all hypothyroid symptoms except alopecia and hirsuitism.

CONCLUSION

The incidence of hyperprolactinemia in hypothyroidism was found to be higher when compared with normal controls. Serum prolactin assessment should be performed on all patients with hypothyroidism (overt and subclinical) before performing further tests.

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.

Subclinical hypothyroidism in infertile women: the importance of continuous monitoring and the role of the thyrotropin-releasing hormone stimulation test

The aim of our study was to assess the prevalence of subclinical hypothyroidism (SH) after administering a thyrotropin-releasing hormone (TRH) stimulation test among women with normal serum thyroid-stimulating hormone (TSH) levels and various causes of infertility. Eighty-seven infertile women (39 with ovulation disorders and 48 with other causes of infertility) had a TRH stimulation test on day 3 - 7 of their cycle. Exaggerated TSH response (>30 mIU/l at 20, 40 or 60 min) following intravenous injection of 400 microg TRH was defined as SH. The TRH test was performed 2 - 4 months after the first visit to the clinic. We found that the prevalence of SH was significantly higher among women with ovulation disorders (20.5%) than among women with normal ovulation (8.3%). In addition, we found that although basal TSH levels were normal at recruitment, 2 - 4 months later these levels were abnormally high in 8% of the women. All these women had an abnormal TRH test. We recommend performing TRH stimulation testing in women suffering from ovulation disorders who have normal basal TSH levels, followed by repeat assessments of thyroid function to enable treatment with thyroxine in cases with abnormal results.

Subclinical hypothyroidism

PURPOSE OF REVIEW

Mild or subclinical hypothyroidism is characterized by normal serum free thyroxine concentrations with elevated serum thyroid-stimulating hormone concentrations. Subclinical hypothyroidism is relatively prevalent in the general population, especially among women and the elderly. The main cause of subclinical hypothyroidism is autoimmune chronic thyroiditis. The present report reviews the most important and recent studies on subclinical hypothyroidism, and discusses the most controversial aspects of this topic.

RECENT FINDINGS

Several studies have demonstrated that subclinical hypothyroidism may affect both diastolic and systolic cardiac function. It may also worsen many risk factors for cardiovascular disease, including hypertension, abnormal endothelial function, and elevated low-density lipoprotein cholesterol concentrations. Furthermore, a growing body of evidence suggests that subclinical hypothyroidism may cause symptoms or progress to symptomatic overt hypothyroidism.

SUMMARY

Prompt treatment of subclinical hypothyroidism in pregnant women is mandatory to decrease risks for pregnancy complications and impaired cognitive development in offspring. Children with subclinical hypothyroidism should be treated to prevent growth retardation. Whether nonpregnant adult patients with subclinical hypothyroidism should be treated, and at what thyroid-stimulating hormone values, is debatable.

The usefulness of a thyrotropin-releasing hormone stimulation test in subfertile female patients

BACKGROUND

The thyrotropin-releasing hormone (TRH) stimulation test is widely used as a screening procedure in subfertile patients to identify subclinical hypothyroidism. However, its usefulness in daily clinical practice has not been proven, despite more than 30 years of use.

MATERIAL AND METHODS

We analyzed data from a cohort of 371 consecutive female subfertility patients, who were screened with an intravenous TRH test when they came for the first evaluation. All patients with positive thyroid peroxidase antibodies, basal TSH <1.5 mU/l, known thyroid disease or actual thyroid medication were not screened and excluded from the analysis.

RESULTS

We found a good correlation between basal and stimulated levels of thyroid-stimulating hormone (TSH). Basal TSH and the difference between stimulated and basal TSH did not correlate with prolactin levels. Definition of a positive TRH test (difference of 15 or 20 mU/l) did not have sufficient sensitivity and specificity, as confirmed by analysis of receiver operating characteristic curves, to identify subclinical hypothyroidism.

CONCLUSION

TRH stimulation testing is not helpful to identify patients with subclinical hypothyroidism and should not be part of initial screening in this group.

Thyroid stimulating hormone inhibits rat granulosa cell steroidogenesis in primary culture

It is not known why hypothyroidism predisposes the ovary to develop cystic follicles in hCG-treated rats. This study examined the effect of TSH on steroidogenesis in cultured granulosa cells. Granulosa cells were isolated from the ovaries of hCG-treated Long-Evans rats. Cells were cultured in medium with either 0 or 100NM: testosterone or 25(OH)cholesterol and treated with 0, 2.5, 10 or 20 ng/ml of TSH. TSH reduced 3β-HSDI activity in these cells to 12% of control. Progesterone secretion decreased by 72% and estradiol secretion was non-detectable during the second day of treatment with 20 ng/ml of TSH. We conclude that TSH is capable of regulating the secretion of progesterone and estradiol by cultured granulosa cells.

Hormone load tests in infertile male patients

The recognition that discreet hormonal abnormalities may cause ovulation disorders in women suggested that the male partner of infertile women might also suffer from unrecognized hormonal dysfunction amendable to substitution therapy. We obtained a combined stimulation test with gonadotropin-releasing hormone (GnRH), thyreotropin-releasing hormone (TRH), and ACTH in 225 males with childless spouses, when the couple sought to have children for at least one year. The following hormone levels were determined: estradiol (E), thyroid-stimulating hormone (TSH), prolactin, testosterone (T), dihydrotestosterone (DHT), androstenedione(A), 17-OH-pregnenolone (17-OH-Preg), 17-OH-progesterone (17-OHP), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), cortisone (F), and 21-desoxycortisone (21DF). Basal and stimulated, and adrenal-testicular steroids with and without ACTH stimulation failed to demonstrate a relevant relationship to semen parameters. Gonadotropin levels had a significant negative correlation to all important semen parameters (testicular volume, sperm count, motility, morphology, and vitality) and were positively correlated to spermiogenetic defects. Stimulated LH values were more clearly associated with spermiogenetic defects than basal LH. Nonetheless, basal FSH concentrations were more informative than LH. Stimulated prolactin values were positively correlated with both gonadotropin and with sperm morphology. E concentrations had a significant positive correlation with both basal and poststimulation DHEAS values, and showed a highly negative correlation with sperm count, morphology, and vitality. In comparison, good sperm parameters were associated with high poststimulation T concentrations. The results of this study suggest that basal FSH and E concentrations, as well as the stimulated LH, T, and prolactin determinations, should be included in the evaluation of male sterility.