Gonadotropin releasing hormone antagonists suppress aromatase and anti-Müllerian hormone expression in human granulosa cells

Effects of controlled ovarian stimulation on thyroid function during pregnancy

Controlled ovarian stimulation (COS) is a major component of assisted reproductive technologies. Clinically, it has been observed that, some women experience changes in thyrotropin levels following COS, which then bring about subclinical hypothyroidism and may adversely affect conception. Studies have also shown that the specific degree as well as the tendency of changes in thyroid function vary with differences in thyroid function before pregnancy, thyroid autoimmunity, the COS regimen, and the observation time point. However, the associated pathophysiological mechanism of the effects of COS on pregnancy has not yet been fully elucidated. This may be because increased estradiol levels, caused by COS, induce increased levels of thyroxine-binding globulin, resulting in a decrease in free thyroxine (FT4) level and an increase in TSH level. Conversely, it has also been observed that human chorionic gonadotropin (hCG) can act directly on thyroid cells, exerting opposite effects on FT4 and TSH levels. Additionally, the effects of COS on thyroid function may be more pronounced, especially in women with autoimmune thyroid disease or thyroid dysfunction before pregnancy, ultimately leading to subclinical hypothyroidism. Here, we review recent research progress regarding the effects of COS on thyroid function during pregnancy.

Gonadotropin releasing hormone (GnRH) antagonist administration to decrease the risk of ovarian hyperstimulation syndrome in GNRH agonist cycles triggered with human chorionic gonadotropin

PURPOSE

In Gonadotropin releasing hormone(GnRH) agonist IVF, after administration of human chorionic gonadotropin(HCG) triggering, there is a risk of ovarian hyperstimulation syndrome(OHSS). Few methods exist to prevent OHSS in these cases. Therefore, we investigated the use of a GnRH antagonist to decrease the risk of OHSS, due to its ability to decrease VEGF production and function.

METHOD

A retrospective cohort study of 171-IVF patients at risk for developing OHSS after a GnRH agonist cycle with HCG trigger was performed from 2011 to 2019. The patient population consisted of women with an unexpected exuberant response to stimulation based on ovarian reserve testing and were triggered with hCG. Women were converted to a freeze-all cycle and received either cabergoline 0.5 mg orally alone for 7 days from the collection(Group 1, n = 123) or received cabergoline 0.5 mg orally and ganirelix, 250 mcg SC for 7-10 days(Group 2, n = 48).

RESULTS

Group 1 had more cases of moderate and severe OHSS than group 2-(25% vs. 10% p = 0.03, and 52% vs. 25% p = 0.001 respectively). Group 1 reported more abdominal discomfort and bloating than group 2(91% vs. 65% p < 0.001) and the presence of free fluid was more frequent in group 1 than group 2(74% vs. 35% p < 0.001). Hemoconcentration and electrolyte disturbances were less severe in group 2 than in group 1 (p < 0.001 all cases).

CONCLUSION

In patients at high risk for developing OHSS after hCG trigger in a GnRH agonist cycle, the addition of GnRH antagonists in the luteal phase may reduce the risk of developing moderate and severe OHSS. The GnRH antagonist likely leads to more rapid luteolysis and down regulation of VEGF production and receptor response, thereby decreasing the hallmark increased vascular permeability.

Conventional GnRH antagonist protocols versus long GnRH agonist protocol in IVF/ICSI cycles of polycystic ovary syndrome women: a systematic review and meta-analysis

Gonadotropin-releasing hormone (GnRH) analogues are commonly used in clinical practice to prevent premature luteinizing hormone (LH) surge during In-Vitro Fertilization/ Intra-Cytoplasmic Sperm Injection (IVF/ICSI) cycles. This review aimed to summarize the available evidence comparing the effects of conventional GnRH antagonist protocols, the most commonly used GnRH antagonist protocols, and GnRH agonist protocols on IVF/ICSI outcomes in women with polycystic ovary syndrome (PCOS). A comprehensive electronic search was carried out in Pubmed, Cochrane CENTRAL, Scopus, Web of Science, CINAHL, TRIP, ClinicalTrials.gov and ISRCTN registry from inception until 24 November 2020 without any language or date restrictions. In addition, reference lists of eligible studies and previous meta-analyses were hand-searched to identify relevant studies. Eligible randomized controlled trials were those designed to compare the effects of conventional GnRH antagonist protocols and GnRH agonist protocols on IVF/ICSI outcomes in PCOS subjects. The Cochrane ROB 2.0 tool was used to assess the risk of bias of each study, and the GRADE assessment was used to evaluate the overall quality of evidence. Data synthesis and analyses were done using Review Manager 5.3 with the assistance of Revman Web. A random-effects model was used for all meta-analysis. Dichotomous outcomes were reported as Relative Risk (RR) and continuous outcomes as Weighted Mean Difference (WMD), both with 95% CIs. The primary outcomes were Live birth rate, Ongoing pregnancy rate, and Ovarian hyperstimulation syndrome (OHSS) rate. Other IVF outcomes were considered secondary outcomes. We included ten studies with 1214 randomized PCOS women. Using GnRH antagonist protocols led to a significantly lower OHSS rate (RR = 0.58; 95% CI: [0.44 to 0.77], P = 0.0002), shorter stimulation duration (WMD = - 0.91; 95% CI: [-1.45 to - 0.37] day, P = 0.0009), lower gonadotropin consumption (WMD = - 221.36; 95% CI: [- 332.28 to - 110.45] IU, P < 0.0001), lower E2 levels on hCG day (WMD = - 259.21; 95% CI: [- 485.81 to - 32.60] pg/ml, P = 0.02), thinner endometrial thickness on hCG day (WMD = - 0.73; 95% CI: [- 1.17 to - 0.29] mm, P = 0.001), and lower number of retrieved oocytes (WMD = - 1.82; 95% CI: [- 3.48 to - 0.15] oocytes, P = 0.03). However, no significant differences in live birth rate, ongoing pregnancy rate, clinical pregnancy rate, multiple pregnancy rate, miscarriage rate and cycle cancellation rate were seen between the GnRH antagonist protocols and the long GnRH agonist one. Although more cycles were cancelled due to poor ovarian response in the GnRH antagonist protocol (RR = 4.63; 95% CI: [1.49 to 14.41], P = 0.008), similar rates of cancellation due to risk of OHSS were noticed in both groups. The differences in IVF/ICSI outcomes may arise from the different patterns of gonadotropins suppression that the GnRH analogues exhibit during the early follicular phase of IVF/ICSI cycles and the divergent direct impacts of these analogues on ovaries and endometrial receptivity. The main evidence limitation was Imprecision. Conventional GnRH antagonist protocols represent a safer and more cost-effective treatment choice for PCOS women undergoing IVF/ICSI cycles than the standard long GnRH agonist protocol without compromising the IVF/ICSI clinical outcomes. The study had no sources of financial support and was prospectively registered at PROSPERO (International Prospective Register of Systematic Reviews) under registration number (CRD42021242476).

Anastrozole plus leuprorelin in early maturing girls with compromised growth: the "GAIL" study

PURPOSE

Aromatase inhibitors have been used to increase predicted adult height (PAH) in boys but in girls only in McCune-Albright syndrome. We investigated whether anastrozole combined with leuprorelin for up to 2 years is safe and effective in improving PAH in girls with early puberty and compromised growth, compared to leuprorelin alone.

METHODS

The "GAIL" study: girls treated with an aromatase inhibitor and an LHRH analogue, ISRCTN11469487, was a 7-year prospective phase IIa study with parallel design, performed at Athens Medical Center (C-A), and Attikon University Hospital, Athens, Greece (C-B). Forty girls, consecutively referred for early puberty (onset 7.5-9 years) with a PAH <-2 or >1.5 SD lower than their target height (TH), were included. Twenty started on leuprorelin sc/im 0.3 mg/kg/month plus anastrozole 1 mg/d p.o. (group-A, C-A) and 20 on leuprorelin (group-B, C-B) for 2 years or until the age of 10 years. Groups did not differ in age, height, BMI, bone age advancement (BAA), and distance of PAH from TH. Follow-up was at 6, 12, 18, and 24 m.

RESULTS

Reduction in BAA was significantly higher in group-A compared to group-B already by 6 m. Despite the transiently significant decrease in height velocity in group-A, gain in PAH SD was almost double by 12 and 18 m vs group-B and reached the maximum of +1.21 ± 0.45 (7.51 cm) vs +0.31 ± 0.37 (1.92 cm, p = 0.001) in group-B at 24 m. Group-A had no clinical or biochemical hyperandrogenism, unchanged normal bone density, and lumbar spine X-rays.

CONCLUSION

The co-administration of anastrozole with leuprorelin safely improves PAH in girls with compromised growth.

Conditional Deletion of Bmal1 in Ovarian Theca Cells Disrupts Ovulation in Female Mice

Rhythmic events in female reproductive physiology, including ovulation, are tightly controlled by the circadian timing system. The molecular clock, a feedback loop oscillator of clock gene transcription factors, dictates rhythms of gene expression in the hypothalamo-pituitary-ovarian axis. Circadian disruption due to environmental factors (eg, shift work) or genetic manipulation of the clock has negative impacts on fertility. Although the central pacemaker in the suprachiasmatic nucleus classically regulates the timing of ovulation, we have shown that this rhythm also depends on phasic sensitivity to LH. We hypothesized that this rhythm relies on clock function in a specific cellular compartment of the ovarian follicle. To test this hypothesis we generated mice with deletion of the Bmal1 locus in ovarian granulosa cells (GCs) (Granulosa Cell Bmal1 KO; GCKO) or theca cells (TCs) (Theca Cell Bmal1 KO; TCKO). Reproductive cycles, preovulatory LH secretion, ovarian morphology and behavior were not grossly altered in GCKO or TCKO mice. We detected phasic sensitivity to LH in wild-type littermate control (LC) and GCKO mice but not TCKO mice. This decline in sensitivity to LH is coincident with impaired fertility and altered patterns of LH receptor (Lhcgr) mRNA abundance in the ovary of TCKO mice. These data suggest that the TC is a pacemaker that contributes to the timing and amplitude of ovulation by modulating phasic sensitivity to LH. The TC clock may play a critical role in circadian disruption-mediated reproductive pathology and could be a target for chronobiotic management of infertility due to environmental circadian disruption and/or hormone-dependent reprogramming in women.

Effects of GnRH agonists on the expression of developmental follicular anti-mullerian hormone in varying follicular stages in cyclic mice in vivo

Gonadotrophin‑releasing hormone (GnRH) agonists (GnRHa) have been widely used to induce a state of downregulation for in vitro fertilization, and its direct effects on the pituitary are well known. However, the effects of GnRHa on the expression of anti‑mullerian hormone (AMH) by follicles in varying stages in vivo remain to be fully elucidated. In the present study 84 cyclic mice were randomly divided equally into four GnRHa groups and three cyclic mice were used as a control group. The expression levels of AMH in follicles of varying stages between days 0 and 7 following GnRHa administration were quantified using immunohistochemistry. The expression of AMH in follicles at various stages revealed dynamic changes during the process of downregulation. AMH in primary follicles initially increased and then decreased gradually. In small and large preantral follicles and in granulosa cells (GCs) surrounding the oocyte of small antral follicles, the expression of AMH began to increase on day 1, was attenuated on day 2, and then increased to a peak. The expression levels of AMH in the GCs surrounding the basement membrane, in contrast to the GCs surrounding the oocyte, were significantly lower and did not increase on day 1. In all stages of follicles, the expression of AMH declined gradually between the peak level and last day of downregulation. On day 7, the varying follicular stages all expressed lower levels of AMH than on day 0. This decrease was more prominent in the higher dose groups, compared with the lower dose groups. In conclusion, GnRHa was observed to induce time‑dependent changes in the expression of AMH at varying follicular stages, which occurred in a dose‑dependent manner.

Gonadotrophin-releasing hormone agonists for fertility preservation: unraveling the enigma?

STUDY QUESTION

Can gonadotrophin-releasing hormone agonists (GnRH-a) preserve long-term fertility when administered prior to and concomitantly with chemotherapy?

SUMMARY ANSWER

GnRH-a display a differential protective effect on fertility, depending upon the specific chemotherapy-induced mechanism of ovarian injury.

WHAT IS KNOWN ALREADY

The role of GnRH-a in fertility preservation has been constantly debated and their use is considered experimental due to conflicting clinical evidence and paucity of data regarding their mechanism for ovarian protection.

STUDY DESIGN, SIZE, DURATION

In vivo model: 7-8 weeks old imprinting control region (ICR) mice were injected with GnRH-a (Leuprolide-acetate) or saline prior to and concomitantly with cyclophosphamide, doxorubicin or saline and sacrificed at various time-points on a longitudinal follow-up; 24 h (n = 36), 1 week (n = 40), 1 month (n = 36) and 9 months (n = 66) post chemotherapy treatment. Blood samples were drawn on Day 0 and on a monthly basis after chemotherapy treatment. On the day of sacrifice, blood samples were drawn and ovaries excised and processed for either immunohistochemistry (IHC), protein or RNA extraction. In vitro model: 21-23 days old Wistar-derived rats were sacrificed, their ovaries excised and primary granulosa cells (PGC) were either isolated for in vitro culture, or processed for immunofluorescence (IF) as well as for protein or RNA extraction.

MATERIALS, SETTING, METHODS

Ovarian reserve was estimated by serial measurements of serum anti-mullerian hormone (AMH), quantified by the AMH Gen II ELISA assay. Ovarian AMH and phosphorylated Akt (pAkt) were detected by immunoblotting. Vascular endothelial growth factor (VEGF) was measured by quantitative PCR. Ovarian GnRH receptor (GnRHR), AMH and CD34 were visualized by IHC, and apoptosis was evaluated using TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end labeling (TUNEL).

MAIN RESULTS AND THE ROLE OF CHANCE

Cyclophosphamide-induced ovarian injury caused a prompt decrease in AMH level (P < 0.01) and a further long-term decline in serum AMH (P = 0.017), indicating damage to the ovarian reserve. Pretreatment with GnRH-a diminished AMH-decrease (P < 0.05) and maintained serum AMH level in the long run (P < 0.05). Doxorubicin-exerted ovarian-vascular-injury is also displayed by an acute increase in ovarian VEGF level (P < 0.05) and a sustained decrease in serum AMH level (P < 0.001). This was followed by ovarian recovery manifested by increased neovascularization. GnRH-a delayed the recovery in AMH level and decreased the level of VEGF (P < 0.001), thus interfering with the vascular recovery subsequent to doxorubicin-induced vascular damage.

LIMITATIONS, REASONS FOR CAUTION

To portray the differential mechanism of each chemotherapy, cyclophosphamide and doxorubicin were given separately, whereas most of the clinical protocols include several types of chemotherapies. Thus, future study should explore a prospective evaluation of various chemotherapies, as well as combined chemotherapeutic protocols.

WIDER IMPLICATIONS OF THE FINDINGS

Our study demonstrates that different chemotherapy agents affect the ovary via diverse mechanisms and thus the administration of GnRH-a concomitantly, could be beneficial to a subpopulation of patients treated with cyclophosphamide-based protocols.

STUDY FUNDING/COMPETING INTERESTS

This work was partially supported by a grant from the Israel Science Foundation (ISF) to I.B.-A. The authors have no conflict of interest to disclose.

[What's new in 2014 about anti-Müllerian hormone?]

The existence of the anti-Müllerian hormone (AMH) has been postulated by Professor Alfred Jost to explain the regression of the Müllerian ducts during male sexual differentiation. Since then, AMH has been purified, its gene and specific receptor, AMHR-II have been cloned. Further, the signaling pathways were identified and it has been observed that AMH was produced by the granulosa cells of growing follicles. From the 2000s, unexpected roles of AMH have been highlighted, reactivating international research on this hormone. It is now well established that AMH plays a key role in the follicular recruitment and development. Over the past years, serum AMH measurements have been proposed as a marker of the follicular ovarian status, and a predictor of assisted reproductive cycles. AMH is also useful to assess the effectiveness of treatment of some gynecological tumors. This article is a review of the past five years advances on the regulation of the expression of AMH and its specific receptor AMHR-II in female.

Loss of LH-induced down-regulation of anti-Müllerian hormone receptor expression may contribute to anovulation in women with polycystic ovary syndrome

STUDY QUESTION

Are anti-Müllerian hormone (AMH) and AMH type II receptor (AMHR-II) mRNAs similarly regulated by gonadotrophins in lutein granulosa cells (GCs) from control, normo-ovulatory and oligo/anovulatory women with polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

AMH mRNA expression was induced by LH only in lutein GC of oligo/anovulatory PCOS women; down-regulation of AMHR-II, induced by LH in control and normo-ovulatory PCOS women, was absent in oligo/anovulatory women.

WHAT IS KNOWN ALREADY

It was suggested that AMH could be responsible for the blockade of follicles at the small antral stage in PCOS women. In keeping with this hypothesis, both AMH and AMHR-II are overexpressed in lutein GCs from oligo/anovulatory PCOS women.

STUDY DESIGN, SIZE, DURATION

Women undergoing IVF were included in this prospective study, either in the control group (30 women) or in the PCOS group (21 normo-ovulatory and 19 oligo/anovulatory patients) between January 2010 and July 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Human lutein GCs were isolated from follicular fluid during IVF protocols. Twenty-four hours after seeding, lutein GCs from each woman were serum starved and cultured for 48 h ± FSH, LH or cAMP. Then AMH and AMHR-II mRNAs were quantified by quantitative RT-PCR and AMH protein concentration was measured in the culture medium by ELISA. Experimental results were analyzed, within each group of women, by the non-parametric Wilcoxon test for paired comparisons between cells cultured in control medium and FSH, LH or cAMP treated cells. Clinical comparisons between the three groups of women were performed on log values using the ANOVA test with Bonferroni correction.

MAIN RESULTS AND THE ROLE OF CHANCE

FSH up-regulated both AMH expression and secretion by lutein GCs from the three groups of women (P < 0.05). LH had no effect on AMH mRNAs levels in lutein GCs from controls and normo-ovulatory PCOS women, but increased AMH expression in oligo/anovulatory PCOS women (P < 0.05). Interestingly, LH and cAMP treatments reduced AMHR-II expression by lutein GCs from controls and normo-ovulatory PCOS women (P < 0.05), but had no effect on AMHR-II mRNA levels in oligo/anovulatory PCOS women.

LIMITATIONS, REASONS FOR CAUTION

The lutein GCs are not the best model to study AMH and AMHR-II regulation by gonadotrophins. Indeed, AMH and AMHR-II are down-regulated in luteinized cells. Furthermore, these cells have been exposed to non-physiological levels of gonadotrophins and hCG. However, AMH and AMHR-II mRNAs are quantifiable by real-time RT-PCR, and the cells are still responsive to FSH and LH. The age of patients is significantly different between control and oligo/anovulatory PCOS women: this may be a bias in the interpretation of results but older women in the control group had a good ovarian reserve.

WIDER IMPLICATIONS OF THE FINDINGS

The overexpression of AMH and AMHR-II in oligo/anovulatory PCOS women could be due to increased LH levels and/or inhibition of its repressive action. The fact that this dysregulation is observed in oligo/anovulatory, but not in normo-ovulatory, PCOS women emphasizes the role of LH in the follicular arrest of PCOS women and suggests that this involves the AMH/AMHR-II system.

STUDY FUNDING/COMPETING INTEREST(S)

The Assistance-Publique Hôpitaux de Paris provided a Contrat d'Interface and the Agence de Biomédecine provided a grant to Nathalie di Clemente. Schering-Plough provided an FARO grant to Alice Pierre. The authors have nothing to disclose.

The extrapituitary effects of GnRH antagonists and their potential clinical implications: a narrated review

Potential roles of gonadotropin-releasing hormone (GnRH) antagonists on GnRH/GnRH receptor systems and their effects on the extrapituitary tissues are largely elusive. In this narrated review, we summarized the systemic effects of GnRH antagonists on ovary, endometrium, embryo implantation, placental development, fetal teratogenicity, reproductive tissue cancer cells, and heart while briefly reviewing the GnRH and GnRH receptor system. GnRH antagonists may have direct effects on ovarian granulosa cells. Data are conflicting regarding their effects on endometrial receptivity. The GnRH antagonists may potentially have detrimental effect on early placentation by decreasing the invasive ability of cytotrophoblasts if the exposure to them occurs during early pregnancy. The GnRH antagonists were not found to increase the rates of congenital malformations. Comparative clinical data are required to explore their systemic effects on various extrapituitary tissues such as on cardiac function in the long term as well as their potential use in other human cancers that express GnRH receptors.

Serum anti-Müllerian hormone as a predictive marker of polycystic ovarian syndrome

Background

The anti-Müllerian hormone (AMH) is a dimeric protein secreted by the female ovaries and has two fundamental roles in follicle genesis. It delays the entrance of the primordial follicle into the pool of follicles in growth and diminishes the sensitivity of the ovarian follicle towards follicle-stimulating hormone (FSH). The purpose of this work was to study the AMH (nv 2.0–6.8 ng/mL) as a marker during assisted reproductive technology (ART), in order to identify cases of infertility due to polycystic ovarian syndrome (PCOS). This syndrome affects 10% of women with infertility problems, and a new biological marker could be useful to general practitioners of internal medicine to help generate the suspicion of PCOS so that they can refer the patient to the gynecologist for confirmation.

Methods

This study enrolled 236 patients aged 26–46 years undergoing assisted reproductive technology at the Institute for Maternal and Child Health, Trieste, Italy. On the third day of the ovarian cycle, the patients were given doses of AMH, FSH, and luteinizing hormone (LH, in cases of AMH < 2.0–6.8 ng/mL). A control pelvic ultrasound was also carried out.

Results

We identified 57 patients who were starting in vitro fertilization or embryo transfer with AMH values within the normal range (3.64 ± 1.51 ng/mL), 77 with values below normal (1.38 ± 0.32 ng/mL), and 96 cases with undetectable values of AMH. Six patients had very high AMH levels (10.0 ± 2.28 ng/mL) and, of these, five were found to have PCOS on pelvic ultrasound examination (P < 0.05). We also found inverse correlations between AMH levels and age (r = −0.52) and between AMH and FSH levels (r = −0.32).

Conclusion

In clinical practice it is common to encounter patients who turn to medicine in search of a cure for female infertility. In our experience, AMH two or three times the normal amount (10 ± 2.28 ng/mL), is a good indication of PCOS and infertility.

Use of in-cycle antimüllerian hormone levels to predict cycle outcome

OBJECTIVE

The goal of this work is to expand the usefulness of antimüllerian hormone (AMH) in predicting in vitro fertilization cycle outcome by demonstrating that AMH concentration obtained in an ongoing treatment cycle predicts both oocyte number and pregnancy.

STUDY DESIGN

Serum samples were obtained from 190 in vitro fertilization patients at onset of follicle-stimulating hormone stimulation. These were analyzed retrospectively during a single cycle in which clinicians were blinded to the results. Our major outcome measures were the number of oocytes obtained and ongoing pregnancy.

RESULTS

Patients with an initial AMH concentration of >3 ng/mL were found to produce a mean of 19.8 oocytes and had an ongoing pregnancy rate of 60.3%. In contrast, those with AMH values of ≤1 ng/mL yielded a mean of 6.2 oocytes and had an ongoing pregnancy rate of 23.4% (P < .0001 for both).

CONCLUSION

Greater AMH serum concentration strongly predicts an increased number of oocytes and ongoing pregnancy (P ≤ .0001).