Gonadotropin-releasing hormone antagonist versus agonist administration in women undergoing controlled ovarian hyperstimulation: cycle performance and in vitro steroidogenesis of granulosa-lutein cells

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).

Which luteal phase support is better for each IVF stimulation protocol to achieve the highest pregnancy rate? A superiority randomized clinical trial

In vitro fertilization (IVF) cycles generate abnormalities in luteal-phase sex steroid concentrations and this represent an important limiting factor to achieve a good pregnancy rate. Although there are evidences about the usefulness of luteal phase support (LPS) after IVF cycles, no consensus exist about the best dose and way of progesterone (PG) administration, the advantages of estradiol (E2) supplementation and which IVF protocol could benefit from one more than other LPS scheme. Aim of the study was to assess the best LPS (low-dose PG, high-dose PG, high-dose PG and E2 supplementation) to achieve the highest clinical/ongoing pregnancy rate according to stimulation protocol, E2 at ovulation induction, endometrial thickness at pick-up and women's age. We conducted a randomized trial on 360 women undergoing IVF (180 treated by long-GnRH agonist, 90 by short-GnRH agonist and 90 by short-GnRH antagonist protocol) and stimulated by recombinant follicle-stimulating hormone alone. Our data demonstrated that high-dose PG is better than low-dose to increase both clinical and ongoing pregnancy rate. E2 supplementation are mandatory in case of short-GnRH antagonist protocol and strongly suggested in all protocols when E2max <5 nmol/l and endometrial thickness <10 mm. In long-GnRH agonist protocols, as well as in patients >35 years, the real advantages of E2 supplementation remain debatable and require further confirmation.

Cessation of gonadotropin-releasing hormone antagonist on triggering day in flexible multiple-dose protocol: A randomized controlled study

Objective

To investigate outcomes of stimulated IVF cycles in which GnRH antagonist was omitted on the ovulation triggering day.

Methods

A total of 86 women who underwent controlled ovarian hyperstimulation with recombinant FSH and GnRH antagonist flexible multiple-dose protocols were recruited and prospectively randomized into the conventional group (group A) or cessation group (group B). The GnRH antagonist, 0.25 mg/day of cetrorelix, was started when the leading follicle reached 14 mm in diameter and was continuously administered until the hCG triggering day (group A, 43 cycles) or until the day before hCG administration (group B, 43 cycles). The maturity of oocytes, fertilization rate, embryo quality, and implantation and clinical pregnancy rates were evaluated.

Results

The duration of ovarian stimulation, total dose of gonadotropins, serum estradiol levels on hCG administration day, and number of oocytes retrieved were not significantly different between the two groups. The total dose of GnRH antagonist was significantly lower in group B than group A (2.5±0.9 vs. 3.2±0.8 ampoules, p<0.05). There was no premature luteinization in any of the subjects. The proportion of mature oocytes and fertilization rate were not significantly different in group B than group A (70.7% vs. 66.7%; 71.1% vs. 66.4%, respectively). There were no significant differences in the implantation or clinical pregnancy rates.

Conclusion

Our prospective randomized study suggested that cessation of GnRH antagonist on the hCG administration day during a flexible multiple-dose protocol could reduce the total dose of GnRH antagonist without compromising its effects on pregnancy rates.

The luteal phase after ovarian stimulation

Evaluation of the luteal phase after ovarian stimulation presents several difficulties. Until today, it has not been proved that in cycles stimulated with clomiphene citrate/human menopausal gonadotrophins, luteal supplementation with progesterone significantly increases implantation rate. On the contrary, it is accepted that in cycles stimulated with GnRH agonists/gonadotrophins, support of the luteal phase is essential for the achievement of pregnancy. In GnRH antagonist cycles luteal supplementation, although widely practised, is not at present supported by randomized controlled trials. Finally, it appears that the combination of gonadotrophin stimulation with human chorionic gonadotrophin results in an inadequate luteal phase with or without the use of either agonists or antagonists.

Direct ovarian effects and safety aspects of GnRH agonists and antagonists

The wide application of gonadotrophin-releasing hormone (GnRH) analogues in assisted reproduction has raised concerns about their potential extra-pituitary actions. Although data from animal studies support the presence of ovarian GnRH receptors and of direct ovarian effects of GnRH analogues, this has not been unequivocally demonstrated in humans. Available evidence suggests, however, the existence of GnRH receptors in human granulosa-luteal cells, while the majority of the studies performed showed that progesterone is inhibited by GnRH agonists in vitro. On the other hand, no difference seems to exist between agonists and antagonists in terms of granulosa-luteal cell steroidogenesis under basal conditions. So far, no studies have suggested an adverse effect of GnRH analogues on the developing human follicle. Moreover, the physiological significance of a direct in-vitro ovarian effect of GnRH analogues remains to be established.

Morphometric and ultrastructural analysis of human granulosa cells after gonadotrophin-releasing hormone agonist or antagonist

Morphological features of granulosa cells can reflect their functional status. The present study was aimed at comparing possible differences in the fine structure of human granulosa cells exposed to gonadotrophin-releasing hormone (GnRH) agonist or antagonist treatment during ovarian stimulation. Cells were obtained from follicular aspirates of 21 women treated with recombinant follicle-stimulating hormone (rFSH) plus either a GnRH agonist or a GnRH antagonist. Conventional light microscopy procedures and computerized image analysis systems were used to identify different cell type morphological patterns and to quantify different cells distribution. Two morphologically distinct granulosa cell populations, defined as large/pale and small/dark cells, were identified and a different distribution in the two groups of women under investigation was found: a significantly higher percentage in large/pale cells was detected in the agonist-treated women (P<0.05), whereas the percentage of small/dark cells was significantly higher in the antagonist-treated group (P<0.05). Ultrastructural observations showed the presence in both cell populations of typical hallmarks of steroidogenic cells, highlighting signs of functional activity in the large/pale cell population. Further investigations are needed to define the possible clinical significance of these morphological findings.

Gonadotropin-releasing hormone antagonist use in controlled ovarian stimulation and intrauterine insemination cycles in women with polycystic ovary syndrome

OBJECTIVE

To observe the effects of ganirelix on controlled ovarian stimulation and intrauterine insemination (COS/IUI) cycles in women with polycystic ovary syndrome (PCOS).

DESIGN

Prospective, randomized, controlled clinical study.

SETTING

An academic clinical research center.

PATIENT(S)

Women with PCOS and anovulatory infertility undergoing COS/IUI.

INTERVENTION(S)

Recombinant FSH therapy was started on day 3. In women assigned to the control group (n = 47), treatment was continued up to the day of hCG administration. In patients assigned to receive GnRH antagonist (n = 42), ganirelix was added when the leading follicle was > or =14 mm.

MAIN OUTCOME MEASURE(S)

Pregnancy rates, serum E(2), P, and LH levels, and follicle numbers at hCG day, prevalence of premature luteinization, and cost of stimulation.

RESULT(S)

Serum E(2), P, and LH levels were significantly lower in the ganirelix group. Although premature luteinization and cycle cancellation was encountered less in the ganirelix group, the pregnancy rates per cycle were similar (15.4% vs. 10.7%). Patients would pay 6,153 dollars more for each pregnancy when using ganirelix.

CONCLUSION(S)

Gonadotropin-releasing hormone antagonist resulted in more monofollicular development, less premature luteinization, and less cycle cancellation in IUI cycles of patients with PCOS; however, the cost of stimulation increased without an improvement in pregnancy rates.

Is the metalloendopeptidase EC 3.4.24.15 (EP24.15), the enzyme that cleaves luteinizing hormone-releasing hormone (LHRH), an activating enzyme?

LHRH (GNRH) was first isolated in the mammalian hypothalamus and shown to be the primary regulator of the reproductive neuroendocrine axis comprising of the hypothalamus, pituitary and gonads. LHRH acts centrally through its initiation of pituitary gonadotrophin release. Since its discovery, this form of LHRH (LHRH-I) has been shown to be one of over 20 structural variants with a variety of roles in both the brain and peripheral tissues. LHRH-I is processed by a zinc metalloendopeptidase EC 3.4.24.15 (EP24.15) that cleaves the hormone at the fifth and sixth bond of the decapeptide (Tyr5-Gly6) to form LHRH-(1–5). We have previously reported that the auto-regulation of LHRH-I (GNRH1) gene expression and secretion can also be mediated by itself and its processed peptide, LHRH-(1–5), centrally and in peripheral tissues. In this review, we present the evidence that EP24.15 is the main enzyme of LHRH metabolism. Following this, we look at the metabolism of other neuropeptides where an active peptide fragments is formed during degradation and use this as a platform to postulate that EP24.15 may also produce an active peptide fragment in the process of breaking down LHRH. We close this review by the role EP24.15 may have in regulation of the complex LHRH system.

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

OBJECTIVE

To investigate the effects of a gonadotropin-releasing hormone antagonist (GnRH-ANT) on the expression of anti-Müllerian Hormone (AMH) and aromatase (via the exon CYP19IIa promoter), in cultured human granulosa cells (hGCs) and the human granulosa cell line (HGL5).

DESIGN

Primary cell cultures of hGCs and culture of HGL5 cells.

SETTING

Academic center.

PATIENT(S)

Women undergoing IVF because of male factor, tubal infertility, or donor eggs.

INTERVENTION(S)

hGCs and HGL5 cells were treated with a GnRH-ANT (1 nM and 1 μM) alone or in combination with cAMP (1 mM). Media was collected and stored at -80°C until assayed.

MAIN OUTCOME MEASURE(S)

mRNA levels of CYP19 IIa, AMH, steroidogenic factor 1 (SF-1) and liver receptor homologue-1 (LRH-1) were determined by quantitative polymerase chain reaction. ELISA was used to determined estradiol (E(2)) levels in the culture media. Pooled results from triplicate experiments were analyzed using one-way analysis of variance with Student-Newman-Keuls multiple-comparison methods.

RESULT(S)

The GnRH-ANT decreased the expressions of CYP19 IIa, AMH, SF-1, and LRH-1. cAMP induced aromatase and AMH expression. Cotreatment with cAMP and GnRH-ANT caused a dose-dependent suppression of AMH and CYP19 IIa mRNA. A GnRH agonist (GnRH-A) increased the mRNA expressions of CYP 19 IIa and AMH. The GnRH-ANT decreased E(2) production in cultured hGCs.

CONCLUSION(S)

GnRH-ANTs, in addition to their central suppressive effects on the pituitary, may have a direct effect on ovarian granulosa cells with inhibition of aromatase and AMH expression. Furthermore, the inhibitory effect could be mediated via suppression of SF-1 and LRH-1, and may play a role in estrogen-mediated ovarian folliculogenesis.

Follicular growth and oocyte maturation in GnRH agonist and antagonist protocols for in vitro fertilisation and embryo transfer

BACKGROUND

The aim of this study was to evaluate the response to treatment in a group of patients undergoing IVF and randomised to receive GnRH-antagonist or the GnRH-agonist. The endpoints were the pattern of follicular growth, the maturity of the oocytes collected, the embryo quality and the pregnancy outcome.

METHODS

A total of 136 patients undergoing IVF were included. Sixty-seven patients were allocated to the GnRH antagonist and 69 patients to the GnRH agonist. GnRH antagonist was administered when the leading follicle reached a diameter of 12-14 mm. GnRH agonist was administered in a long luteal protocol.

RESULTS

The mean numbers of oocytes retrieved and mature oocytes were significantly higher in the agonist than in the antagonist group (p < 0.02 and p < 0.01, respectively). Embryo quality, implantation rate, clinical pregnancy rates, ongoing pregnancy rate and miscarriage rate were similar in both groups.

CONCLUSIONS

Better follicular growth and oocyte maturation are achieved with GnRH agonist treatment. However, both regimens seem to have similar efficacy in terms of implantation and pregnancy rates. Further studies clarifying the effect of the GnRH antagonist on ovarian function are needed, as well as a clear definition of the best period of the follicular phase for the GnRH antagonist administration.

The decrease of serum luteinizing hormone level by a gonadotropin-releasing hormone antagonist following the mild IVF stimulation protocol for IVF and its clinical outcome

PURPOSE

While performing the mild ovarian stimulation protocol with a GnRH antagonist, the pregnancy rate was compared between the groups, which were divided by the degree that the luteinizing hormone (LH) level decreased.

MATERIALS AND METHODS

Patients aged 27 to 42years (36.1 +/- 3.79) underwent 308 IVF cycles who opted for IVF via the mild ovarian stimulation protocol began clomiphene citrate on day 3 and recombinant FSH on day 5. A GnRH antagonist was administered when the dominant follicle reached 14mm. Serum LH was measured at the time of GnRH antagonist administration and at the time of hCG injection. The pregnancy rate and implantation rate were compared between 50 cycles in which the LH level dropped less than one-third and the control (LH level within 1/3).

RESULT(S)

The pregnancy rate for the group in which the LH level fell less than one third was 18%. Conversely, the pregnancy rate for the control group was 39%. The implantation rate was 18% for the less than one-third group and 26% for the control group. Both the pregnancy rate and the implantation rate for the group in which the LH level fell less than one-third were significantly lower than that of control (p < 0.02).

CONCLUSION(S)

When performing the mild ovarian stimulation protocol, serum LH should be followed. If the serum LH level is less than one-third at the time of hCG injection, both the pregnancy rate and implantation rate are significantly lower.

Serum cetrorelix concentrations do not affect clinical pregnancy outcome in assisted reproduction

OBJECTIVE

To analyze the potential association between serum cetrorelix levels and clinical pregnancy outcome in patients who had undergone assisted reproduction cycles with a GnRH antagonist cetrorelix acetate 3-mg injection.

DESIGN

Retrospective case-control study.

SETTING

University-affiliated private-assisted reproduction center.

PATIENT(S)

130 IVF and intracytoplasmic sperm injection first cycles, treated with the same cetrorelix acetate protocol, in two matched groups according to whether the cycle resulted in clinical pregnancy (n = 56) or not (n = 74).

INTERVENTION(S)

Cetrorelix acetate administration at 3 mg in a sandwich protocol.

MAIN OUTCOME MEASURE(S)

Serum cetrorelix concentrations on the day of hCG administration with regard to clinical pregnancy outcome, pre- versus post-hCG percent change in serum E(2) levels and implantation rates.

RESULT(S)

The cetrorelix serum concentrations were in the range of 0.29 to 5.12 ng/mL. The comparisons between groups with and without clinical pregnancy revealed comparable serum cetrorelix levels. There was no significant correlation between the serum cetrorelix concentrations and percent change in pre- versus post-hCG serum E(2) levels. Serum cetrorelix levels were comparable among patients with various implantation rates.

CONCLUSION(S)

Although a wide range of serum cetrorelix levels could be detected during a GnRH antagonist cycle, these levels were comparable in patients with and without clinical pregnancies.

Early cleavage does not predict treatment outcome following the use of GnRH antagonists in women older than 35

OBJECTIVE

To compare the early-cleavage rates and the implantation potential of embryos between the GnRH antagonist and agonist long stimulation protocols in women older than 35 years.

DESIGN

Retrospective analysis.

SETTING

Academic medical center.

PATIENTS

Two hundred twenty patients older than 35 years old underwent IVF.

INTERVENTION(S)

Sixty-eight patients received GnRH antagonist protocol (GnRH antagonist group) and 152 patients received GnRH agonist long stimulation protocol (GnRH agonist group).

MAIN OUTCOME MEASURE(S)

Early-cleavage rate of zygotes, implantation rate, and pregnancy rate.

RESULT(S)

Early-cleavage rate of zygotes was significantly lower in the GnRH antagonist group than agonist group (21.8% vs. 32.6%, P<.0001). In the GnRH antagonist group, the pregnancy rate was not significantly different between the early-cleavage and late-cleavage subgroups (40.0% vs. 47.4%). In the GnRH agonist group, the pregnancy rate was significantly higher in the early-cleavage subgroup than in the late-cleavage subgroup (61.0% vs. 29.8%, P<.0001).

CONCLUSION(S)

In women older than 35 years, the early-cleavage rate of zygotes is significantly lower in the GnRH antagonist group than the agonist group. Early-cleavage status of zygotes is not a reliable predictor for embryo implantation in patients receiving the GnRH antagonist protocol.

Effects of gonadotropin-releasing hormone agonist/recombinant follicle-stimulating hormone versus gonadotropin-releasing hormone antagonist/recombinant follicle-stimulating hormone on follicular fluid levels of adhesion molecules during in vitro fertilization

OBJECTIVE

To compare the effects of GnRH-agonist/recombinant rFSH versus GnRH-antagonist/recombinant FSH stimulation on follicular fluid levels of soluble intercellular adhesion molecule (sICAM)-1 and vascular cell adhesion molecule-1 (sVCAM-1) during in vitro fertilization (IVF).

DESIGN

Prospective, randomized study.

SETTING

University hospital.

PATIENT(S)

Seventy-three women underwent IVF.

INTERVENTION(S)

GnRH-agonist/rFSH or GnRH-antagonist/rFSH administration and collection of follicular fluid from 3 small (11-14 mm in diameter) and 3 large (18-21 mm in diameter) follicles on the day of oocyte retrieval.

MAIN OUTCOME MEASURE(S)

Follicular fluid levels of sICAM-1 and sVCAM-1 and intrafollicular estradiol and progesterone were also measured.

RESULT(S)

Women who underwent GnRH-agonist/rFSH showed higher concentrations of sICAM-1 in both small and large follicles were compared with patients who received GnRH-antagonist/rFSH treatment; follicular fluid levels of sVCAM-1 were similar between the 2 stimulation protocols. Content of sICAM-1 in small and large follicles positively correlated with the number of follicles of > or =15 mm and the number of oocytes that were retrieved in both study groups. Concentrations of follicular fluid sVCAM-1 and progesterone were higher in large than in small follicles and were correlated positively to each other in both follicular classes.

CONCLUSION(S)

In IVF, GnRH-agonist/rFSH is associated with higher follicular fluid levels of sICAM-1 compared with GnRH-antagonist/rFSH regimen. Intrafollicular sICAM-1 content may predict ovarian response, and sVCAM-1 appears as an indicator of the degree of follicular luteinization.

Gonadotrophin stimulation of non-luteinized granulosa cells increases steroid production and the expression of enzymes involved in estrogen and progesterone synthesis

BACKGROUND

In regular IVF treatment, mature oocytes are collected with their luteinized granulosa cells (GCs). When in vitro maturation (IVM) of the oocytes is performed, non-luteinized GCs can be collected. We have investigated how these cells respond to gonadotrophin stimulation in culture.

METHODS

GCs were collected from patients undergoing IVM treatment and compared with GCs from IVF patients. The cells were stimulated with FSH and/or hCG. After 48 h, culture media were collected for hormone analysis, and RNA was isolated for gene expression analysis.

RESULTS

In IVM GCs, hCG and FSH alone and in combination induced significantly increased progesterone production, and FSH alone and in combination with hCG increased estrogen production. We also studied the gene expression of P-450aromatase and P-450scc and the receptors for FSH and LH. In non-luteinized GCs, the expression levels of P-450aromatase increased with all treatments, and P-450scc expression increased with the combined FSH and hCG treatment. LHR expression increased with FSH treatment, but the FSH receptor expression did not change with different treatments.

CONCLUSIONS

Non-luteinized GCs behaved differently from luteinized GCs in culture. The data help understand the final stages of maturation of human oocytes and follicles.

Gonadotropin-releasing hormone antagonists do not influence the secretion of steroid hormones but affect the secretion of vascular endothelial growth factor from human granulosa luteinized cell cultures

OBJECTIVE

To evaluate the secretion of E(2), P, and vascular endothelial growth factor (VEGF) in human granulosa luteinized cell cultures with the presence of a gonadotropin-releasing hormone (GnRH) agonist or antagonist.

DESIGN

In vitro cell culture study.

SETTING

Research laboratory of a university hospital.

PATIENTS

Granulosa luteinized cells were obtained from 24 patients undergoing ovarian stimulation for IVF treatment.

INTERVENTIONS

Granulosa cells were cultured for 48 hours with 1 nM of cetrorelix or leuprorelide. For a further 48 hours, granulosa cells were cultured with or without the combination of cetrorelix plus leuprorelide.

MAIN OUTCOMES

At the end of each culturing period, the concentrations of E(2), P, and VEGF were measured in culture supernatants by immunoassays.

RESULTS

Estradiol and P concentrations were similar between the culture supernatants from controls and treatment groups. The VEGF concentrations in supernatants from cultures with cetrorelix (2,315.1 +/- 1,565.5 pg/mL) were moderately, but significantly, lower than in controls (2,604.3 +/- 1,907.1 pg/mL) or cultures with leuprorelide (2,558.8 +/- 1,403.1 pg/mL).

CONCLUSIONS

The GnRH analogues do not affect steroidogenesis in human granulosa luteinized cell cultures. The GnRH antagonists moderately affect the secretion of VEGF from human granulosa luteinized cells.

Effect of gonadotropin-releasing hormone agonist and antagonist on steroidogenesis of low responders undergoing in vitro fertilization

The aim of the study was to investigate the cause of the lower estradiol (E(2)) concentration in women treated with gonadotropin-releasing hormone (GnRH) antagonist compared with those treated with agonist protocol in in vitro fertilization (IVF). Thirty patients who were known low responders were prospectively randomized into two equal groups for IVF treatment. Group 1 used GnRH agonist (flare-up) protocol and group 2 used antagonist protocol. The results showed that serum luteinizing hormone (LH) levels were significantly higher in the agonist group during the folliculogenesis stage. Despite this higher LH, serum E(2) levels were significantly higher in the agonist group on cycle day 2 only, not on day 5 or day 9. The significantly higher E(2) level in the agonist group reappeared on the day of administration of human chorionic gonadotropin (hCG). The rate of folliculogenesis in the antagonist group was faster than in the agonist group; therefore their E(2) production should have been higher on hCG day. Furthermore, the rate of decline in E(2) after hCG administration was significantly higher in the antagonist group. These findings, along with the fact that both groups received exogenous LH (human menopausal gonadotropin) that should optimize steroidogenesis and make the difference in E(2) insignificant, enable us to conclude that GnRH antagonists have a suppressive effect on the production of E(2).

Comparison of embryo implantation in Wistar rats that underwent ovarian stimulation using exogenous gonadotropins associated with cetrorelix acetate or leuprolide acetate

OBJECTIVE

To compare embryo implantation in Wistar rats submitted to ovarian stimulation using recombinant FSH (rFSH) with cetrorelix acetate or leuprolide acetate.

DESIGN

Experimental study.

SETTING

Faculty of medicine animal facility.

PATIENT(S)

Fifty-six female Wistar rats with normal estrus cycles and 30 male.

INTERVENTION(S)

Ovarian stimulation and laparotomy (by the day 13 of gestation).

MAIN OUTCOME MEASURE(S)

Embryo implantation.

RESULT(S)

The female rats were subdivided into four groups: group 1, medicated with rFSH, hCG, and cetrorelix acetate; group 2, medicated with rFSH, hCG, and leuprolide acetate; group 3, medicated with rFSH and hCG; and group 4, in which only saline solution was administered. The female rats were mated with fertile male rats on the day of hCG administration with copulation confirmed through cytologic vaginal analysis. The females were killed on the 13th day of gestation. After laparotomy, comparison and identification was done regarding the numbers of corpora lutea and embryo implantations and gestation rates. Group 1 presented lower numbers of corpora lutea and embryo implantations in comparison to the other groups (P<.05). A difference was not found in the gestation rates between the groups.

CONCLUSION(S)

The number of embryo implantations in Wistar rats medicated with rFSH and cetrorelix acetate is lower than that of rats medicated with rFSH and leuprolide acetate.

The role of aromatase inhibitors in ameliorating deleterious effects of ovarian stimulation on outcome of infertility treatment

Clinical utilization of ovulation stimulation to facilitate the ability of a couple to conceive has not only provided a valuable therapeutic approach, but has also yielded extensive information on the physiology of ovarian follicular recruitment, endometrial receptivity and early embryo competency. One of the consequences of the use of fertility enhancing agents for ovarian stimulation has been the creation of a hyperestrogenic state, which may influence each of these parameters. Use of aromatase inhibitors reduces hyperestrogenism inevitably attained during ovarian stimulation. In addition, the adjunct use of aromatase inhibitors during ovarian stimulation reduces amount of gonadotropins required for optimum stimulation. The unique approach of reducing hyperestrogenism, as well as lowering amount of gonadotropins without affecting the number of mature ovarian follicles is an exciting strategy that could result in improvement in the treatment outcome by ameliorating the deleterious effects of the ovarian stimulation on follicular development, endometrial receptivity, as well as oocyte and embryo quality.

GnRH antagonist improved blastocyst quality and pregnancy outcome after multiple failures of IVF/ICSI-ET with a GnRH agonist protocol

BACKGROUND

To determine the efficacy of a gonadotrophin-releasing hormone (GnRH) antagonist, cetrorelix, in improving the quality of embryos and pregnancy outcome, we performed a study in patients with a history of multiple failures of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles with a GnRH agonist (GnRHa) long protocol.

METHODS

Forty women with no live births after conventional IVF or ICSI embryo transfer (ET) and subsequent blastocyst transfer (BT) with a GnRHa long protocol entered this study. The treatment protocol consisted of a daily dose of clomiphene citrate 100 mg for 5 days and gonadotrophin injections daily from cycle day 4 onward. Cetrorelix, 0.25 mg/day, was started when the leading follicle reached 14 mm. Induction of ovulation was triggered with human chorionic gonadotrophin (HCG) (N = 36) or GnRHa (N = 4). It was possible to perform BT in 38 patients.

RESULTS

Comparison of the results with the results for BT with the previous GnRHa protocol showed no significant differences in number of oocytes retrieved or the zygote- and blastocyst-development rate. With the cetrorelix protocol, however, number of patients whose embryos had developed to at least one expanded blastocyst on day 5 was significantly higher than with the GnRHa protocol (25 vs. 9) (p < 0.001), and 16 of the women became pregnant (42.1%), with 7 delivering 9 infants, 4 ending in abortion (25%), and 5 in progressing.

CONCLUSIONS

The use of a GnRH antagonist in controlled ovarian hyperstimulation improves the outcome of pregnancy of patients with a history of multiple failure of IVF/ICSI-ET in a GnRHa protocol, most likely due to improvement of the quality of the blastocysts generated.

Luteinizing hormone concentrations after gonadotropin-releasing hormone antagonist administration do not influence pregnancy rates in in vitro fertilization–embryo transfer

OBJECTIVE

To determine the impact of circulating LH concentrations during controlled ovarian hyperstimulation on the outcome of IVF.

DESIGN

Retrospective study.

SETTING

University hospital.

PATIENT(S)

Two-hundred seventy women who had a short stimulation protocol with GnRH antagonist and ovarian stimulation with recombinant FSH (rFSH).

INTERVENTION(S)

GnRH antagonist and rFSH were administered SC; blood samples were collected on the day of GnRH antagonist administration, 1 day after, and on the day of hCG administration.

MAIN OUTCOME MEASURE(S)

A threshold of 0.5 IU/L on the day of hCG was chosen to discriminate between women with LH concentrations <or=0.5 IU/L (group A, n = 119) or >0.5 IU/L (group B, n = 151).

RESULT(S)

The two groups were comparable with regard to the clinical parameters. In group A, significantly lower LH concentrations were observed on day 9 of the cycle and on the day of hCG administration. The numbers of oocytes retrieved, embryos obtained, and embryos cryopreserved were significantly higher in group A compared with group B. The proportion of clinical pregnancies was similar in the two groups (21.1% vs. 22.7 % per ET).

CONCLUSION(S)

In GnRH antagonist and rFSH protocols, suppressed serum LH concentrations do not have any influence on the final stages of follicular maturation, pregnancy rates, or outcomes.

Effect of in vivo GnRH agonist and GnRH antagonist on hCG and insulin-stimulated progesterone production by human granulosa-lutein cells in vitro

PURPOSE

To investigate hCG and insulin-stimulated progesterone (P) production by human granulosa-lutein cells (hGLC) in vitro.

METHODS

hGLCs were isolated from patients undergoing IVF-ET cycles in which GnRH agonist or GnRH antagonist was used to prevent a midcycle gonadotropin surge. The cells were cultured for 3 days, and then treated with hCG 0.5, 1, and 10 IU/I, and insulin 0.01, 0.1, and 1 microM in serum free conditions. In vitro P production was measured by enzyme immunoassay.

RESULTS

hCG stimulated P production by hGLCs from cycles in which GnRH antagonist was used, but a blunted response was seen in GnRH-agonist treated cycles. Insulin-stimulated P production was similar in cells from cycles in which GnRH-agonist or GnRH-antagonist treatment was used.

CONCLUSIONS

Because insulin and hCG may share common pathways beyond the level of receptor activation, we hypothesize that GnRH agonist, but not GnRH antagonist, may affect the expression and/or activation of LH receptors in the hGLCs.

Human ovarian steroid secretion in vivo: effects of GnRH agonist versus antagonist (cetrorelix)

BACKGROUND

In order to investigate whether gonadotrophin-releasing hormone (GnRH) antagonists exert a significant effect on steroid secretion in vivo compared with GnRH agonists, concentrations of sex steroid hormones (oestradiol, progesterone and testosterone) were studied in follicular fluid from women undergoing ovarian stimulation and treated with either GnRH agonist or antagonist. In addition, the correlation between follicular fluid steroid hormone concentrations and variables of follicular and oocyte development was evaluated.

METHODS

Microparticle enzyme immunoassay and radioimmunoassays were used.

RESULTS

The mean (SEM) follicular fluid oestradiol concentration was significantly lower in patients treated with GnRH antagonist than in those treated with GnRH agonist (542.0 +/- 76.9 versus 873.0 +/- 105.1 pg/ml, P = 0.02), which correlates with the mean serum oestradiol concentrations found in these two groups. No significant differences were found between groups in follicular fluid progesterone concentrations. Women undergoing GnRH antagonist treatment showed similar concentrations of follicular fluid testosterone compared with GnRH agonist-treated women (14.8 +/- 1.1 versus 13.3 +/- 2.7 ng/ml). The oestradiol:testosterone ratio was markedly reduced in women treated with GnRH antagonist (49.1 +/- 2.3 versus 60.1 +/- 4.4, P = 0.04). In contrast, no differences were found either in the progesterone:testosterone ratio, or in the oestradiol:progesterone ratio.

CONCLUSIONS

GnRH antagonist therapy in women undergoing ovarian stimulation had a significant effect on ovarian follicular steroidogenesis.

Ovulation induction disrupts luteal phase function

Abnormalities in the luteal phase have been detected in virtually all the stimulation protocols used in in vitro fertilization, on both the hormonal and endometrial levels. Supraphysiological follicular or luteal sex steroid serum concentrations, altered estradiol: progesterone (E2/P) ratio, and disturbed luteinizing hormone pituitary secretion leading to corpus luteum insufficiency or a direct drug effect have been postulated as the main etiologic factors. Luteinizing hormone supports corpus luteum function, and low LH levels have been described after human menopausal gonadotropin treatment, after gonadotropin-releasing hormone (GnRH)-agonist treatment, or after GnRH-antagonist treatment. These low luteal LH levels may lead to an insufficient corpus luteum function and consequently to a shortened luteal phase or to the low luteal progesterone concentrations frequently described after ovulation induction. A direct effect of the GnRH agonist or GnRH antagonist on human corpus luteum or on human endometrium and thus on endometrial receptivity cannot be excluded, as GnRH receptors have been described in both compartments. Endometrial histology has revealed a wide range of abnormalities during the various stimulation protocols. In GnRH-agonist cycles, mid-luteal biopsies have revealed increased glandulo-stromal dyssynchrony and delay in endometrial development, strong positivity of endometrial glands for progesterone receptors, decreased alphavbeta3-integrin subunit expression, and earlier appearance of surface epithelium pinopodes. These factors suggest a shift forwards of the implantation window. Progesterone supplementation improves endometrial histology, and its necessity has been well established, at least in cycles using GnRH agonists.

Dynamics of the development of multiple follicles during ovarian stimulation for in vitro fertilization using recombinant follicle-stimulating hormone (Puregon) and various doses of the gonadotropin-releasing hormone antagonist ganirelix (Orgalutran/Antagon)

OBJECTIVE

To investigate relations between dose of GnRH antagonist and follicular phase characteristics.

DESIGN

Randomized controlled multicenter trial.

SETTING

Tertiary referral fertility centers.

PATIENT(S)

Three hundred and twenty-nine IVF patients.

INTERVENTION(S)

Ovarian stimulation for IVF with recombinant FSH starting on cycle day 2. From cycle day 7 onwards, cotreatment was provided with 0.0625, 0.125, 0.25, 0.5, 1.0, or 2.0 mg/d GnRH antagonist.

MAIN OUTCOME MEASURE(S)

Number of follicles, total follicular surface area, gonadotropin, and serum steroid concentrations.

RESULT(S)

In 311 patients, similar follicular growth was observed in all treatment groups. FSH levels increased during the follicular phase. Late follicular phase LH, androstenedione (AD), and E(2) levels showed a GnRH antagonist dose-related decrease (P<0.05). Late follicular phase E(2) levels correlated with total follicular surface area, AD, LH, and FSH (all P<0.001). Increasing GnRH antagonist doses exhibited additional suppressive action on E(2) levels.

CONCLUSION(S)

Follicular growth was unaffected by the dose of GnRH antagonist. A rise in follicular phase FSH serum concentrations during the follicular phase, largely related to exogenous FSH, enabled ongoing follicular growth in all treatment groups. The effect of GnRH antagonist on late follicular phase E(2) levels could not be exclusively attributed to suppression of LH.

Embryo implantation and GnRH antagonists: ovarian actions of GnRH antagonists

The gonadotrophin-releasing hormone (GnRH) antagonists, cetrorelix and ganirelix, have both been approved for ovarian stimulation to prevent a premature LH surge. Since GnRH receptors and their gene expression have been detected in human ovary, concern has risen over whether GnRH antagonists might affect ovarian function. Three large trials which compared GnRH agonists (used in the standard protocol worldwide), with the new antagonist treatment found no significant differences concerning the most important goals, e.g. pregnancy rate, fertilization and quality of oocytes. However, the concentration of oestradiol, and the pregnancy and implantation rates were lower in GnRH antagonist-treated patients. These findings again fuelled the debate about the possible extrapituitary effects of GnRH antagonists. Here, we review the conflicting data in the literature on the ovarian effects of GnRH antagonists and discuss our own results. In our view, it is unlikely that GnRH antagonists have a relevant impact on ovarian steroidogenesis and function; however, GnRH antagonists may exert other effects on the ovary.

Effect of the gonadotropin-releasing hormone antagonist ganirelix on cyclic adenosine monophosphate accumulation of human granulosa-lutein cells

OBJECTIVE

To evaluate whether the GnRH antagonist ganirelix exerts an effect on cyclic adenosine monophosphate (cAMP) production of human granulosa-lutein (GL) cells in vitro.

DESIGN

In vitro cell culture study.

SETTING

Research laboratory of a university hospital.

PATIENT(S)

Mural GL and cumulus cells were obtained from 15 patients on whom controlled ovarian hyperstimulation was being performed for intracytoplasmic sperm injection treatment.

INTERVENTION(S)

Mural GL and cumulus cells were cultured for 48 hours with and without 1 nM ganirelix or triptorelin. For the last 6 hours, the cells were either exposed to 1-5 IU hCG or left unstimulated.

MAIN OUTCOME MEASURE(S)

At the end of the culturing period, the intracellular and extracellular cAMP accumulations were measured by an (125)I-scintillation proximity assay.

RESULT(S)

hCG induced dose-dependent increases in total cAMP accumulation. Stimulation with 1 IU/mL hCG resulted in 9-fold and 13-fold increases, and 5 IU/mL hCG resulted in 19-fold and 14-fold increases in total cAMP release from cumulus and mural GL cells, respectively. On the other hand, treatments with 1 nM GnRH antagonist ganirelix and 1 nM GnRH agonist triptorelin did not exert any significant changes on the basal and hCG-stimulated cAMP accumulation of mural GL cells and cumulus cells as compared with controls.

CONCLUSION(S)

Ganirelix does not influence basal and hCG-stimulated cAMP accumulation of human GL cells in vitro. cAMP is apparently not involved in the mechanism of action of GnRH analogs in human ovary.

Embryo implantation and GnRH antagonists: embryo implantation: the Rubicon for GnRH antagonists

When gonadotrophin-releasing hormone (GnRH) was discovered, the agonist and antagonist of GnRH were developed to control the release of FSH and LH by the gonadotrophs. More than 10 years of research were needed to develop a GnRH antagonist free of histamine release. Recent studies have shown that these GnRH antagonists are effective in preventing a rise in LH during ovarian stimulation in IVF. However, a decrease in ongoing pregnancies seems to suggest that implantation rates per transferred embryo are reduced in GnRH antagonist-stimulated cycles. In my opinion, these data highlight an area less well known to clinicians: the role of the GnRH antagonist at the cellular level in extrapituitary tissues. There are sufficient data in the literature suggesting that GnRH antagonist is an inhibitor of the cell cycle by decreasing the synthesis of growth factors. Given that, for folliculogenesis, blastomere formation and endometrium development, mitosis is everything; the interaction between the GnRH antagonist and the GnRH receptor (present in all these cells and tissues) may compromise the mitotic programme of these cells. This is the Rubicon for the GnRH antagonist: to demonstrate irrevocably that, at the minimal doses necessary to suppress LH release, it does not affect processes such as implantation, embryo development and folliculogenesis.

Ovarian stimulation with HMG: results of a prospective randomized phase III European study comparing the luteinizing hormone-releasing hormone (LHRH)-antagonist cetrorelix and the LHRH-agonist buserelin. European Cetrorelix Study Group

In this prospective and randomized study, 188 patients received the luteinizing hormone-releasing hormone (LHRH) antagonist cetrorelix, and 85 patients the LHRH agonist buserelin to prevent endogenous luteinizing hormone (LH) surges during ovarian stimulation in in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles. Ultimately, 181 patients (96.3%) in the cetrorelix group, and 77 (90.6%) in the buserelin group, reached the day of the human chorionic gonadotrophin (HCG) injection. The mean number of human menopausal gonadotrophin (HMG) ampoules administered and the mean number of stimulation days with HMG were significantly less in the cetrorelix group than in the buserelin group (P < 0.01). A rise in LH and progesterone concentrations was observed in three of the 188 patients (1.6%) who received cetrorelix. On the day of the HCG administration, more follicles of a small diameter (11-14 mm) were observed in the buserelin group than in the cetrorelix group (P = 0. 02) and the mean serum oestradiol concentration was significantly higher in patients who received buserelin than in those who received cetrorelix (P < 0.01). Similar results were observed in fertilization, cleavage and pregnancy rates in the two groups. In conclusion, the use of the LHRH antagonists might be considered more advantageous because of the short-term application needed to inhibit gonadotrophin secretion, so allowing a reduction in the treatment time in a clinically significant manner.

Gonadotropin-releasing hormone agonist use in assisted reproduction cycles: the influence of long and short regimens on pregnancy rates

OBJECTIVE

To compare the efficacy of GnRH agonists used in either the flare (short) or down-regulation (long) regimen as part of IVF or GIFT treatment cycles.

DESIGN

Observational study.

SETTING

Three IVF clinics.

PATIENT(S)

One thousand two hundred forty-four couples accepted for IVF or GIFT treatment at participating clinics.

INTERVENTION(S)

In vitro fertilization or GIFT protocols standard to each clinic were recorded.

MAIN OUTCOME MEASURE(S)

Treatment cycle characteristics and outcomes, including E2 level, number of oocytes retrieved, and clinical pregnancy rate.

RESULT(S)

At site 1, there were 146 clinical pregnancies in 980 flare cycles, for a pregnancy rate of 14.9%, compared with 148 clinical pregnancies in 650 down-regulation cycles, for a pregnancy rate of 22.8%. This difference persisted after adjustment for age, primary infertility diagnosis, GIFT or IVF therapy, and year of treatment, and appeared to be mediated largely by the number of oocytes retrieved (mean, 9.8 for downregulation and 8.7 for flare in the first cycle). Despite having fewer oocytes retrieved, women who received flare regimens had higher E2 levels before hCG administration.

CONCLUSION(S)

Women who received GnRH agonists in a flare regimen had 11% fewer oocytes retrieved and a 35% reduction in the clinical pregnancy rate compared with those who received them in a down-regulation regimen; this difference was not explained by patient selection factors.

Luteal phase and clinical outcome after human menopausal gonadotrophin/gonadotrophin releasing hormone antagonist treatment for ovarian stimulation in in-vitro fertilization/intracytoplasmic sperm injection cycles

The luteal phase hormonal profile and the clinical outcome of 69 patients undergoing in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) after ovarian stimulation with human menopausal gonadotrophin (HMG) and the gonadotrophin-releasing hormone (GnRH) antagonist Cetrorelix were analysed. Twenty-four patients received Cetrorelix 0.5 mg (group I) while in 45 patients Cetrorelix 0.25 mg was administered (group II). Human chorionic gonadotrophin (HCG) was used as luteal support. Nine clinical pregnancies were obtained in group I (37.5%) and 12 in group II (26. 6%). These results were not significantly different. Serum progesterone and oestradiol concentrations did not differ between the two groups either in pregnant or non-pregnant patients. An expected decrease of the same hormones was observed 8 days after the pre-ovulatory HCG injection in non-pregnant women. With regard to serum luteinizing hormone concentrations, a decrease was observed 2 days after the pre-ovulatory HCG injection and was maintained at almost undetectable levels throughout the entire luteal phase in both conception and non-conception cycles of group I and group II. This study demonstrates that different doses of GnRH antagonist do not have any impact on the luteal phase of IVF/ICSI cycles when hormonal support is given.