GnRH antagonists and endometrial receptivity in oocyte recipients: a prospective randomized trial

A modified flexible GnRH antagonist protocol using antagonist early cessation and a gonadotropin step-down approach improves live birth rates in fresh cycles: a randomized controlled trial

STUDY QUESTION

Can pregnancy outcomes following fresh elective single embryo transfer (eSET) in gonadotropin-releasing hormone (GnRH) antagonist protocols increase using a gonadotropin (Gn) step-down approach with cessation of GnRH antagonist on the day of hCG administration (hCG day) in patients with normal ovarian response?

SUMMARY ANSWER

The modified GnRH antagonist protocol using the Gn step-down approach and cessation of GnRH antagonist on the hCG day is effective in improving live birth rates (LBRs) per fresh eSET cycle.

WHAT IS KNOWN ALREADY

Currently, there is no consensus on optimal GnRH antagonist regimens. Studies have shown that fresh GnRH antagonist cycles result in poorer pregnancy outcomes than the long GnRH agonist (GnRHa) protocol. Endometrial receptivity is a key factor that contributes to this phenomenon.

STUDY DESIGN, SIZE, DURATION

An open label randomized controlled trial (RCT) was performed between November 2021 and August 2022. There were 546 patients allocated to either the modified GnRH antagonist or the conventional antagonist protocol at a 1:1 ratio.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Both IVF and ICSI cycles were included, and the sperm samples used were either fresh or frozen from the partner, or from frozen donor ejaculates. The primary outcome was the LBRs per fresh SET cycle. Secondary outcomes included rates of implantation, clinical and ongoing pregnancy, miscarriage, and ovarian hyperstimulation syndrome (OHSS), as well as clinical outcomes of ovarian stimulation.

MAIN RESULTS AND THE ROLE OF CHANCE

Baseline demographic features were not significantly different between the two ovarian stimulation groups. However, in the intention-to-treat (ITT) population, the LBRs in the modified antagonist group were significantly higher than in the conventional group (38.1% [104/273] vs. 27.5% [75/273], relative risk 1.39 [95% CI, 1.09-1.77], P = 0.008). Using a per-protocol (PP) analysis which included all the patients who received an embryo transfer, the LBRs in the modified antagonist group were also significantly higher than in the conventional group (48.6% [103/212] vs. 36.8% [74/201], relative risk 1.32 [95% CI, 1.05-1.66], P = 0.016). The modified antagonist group achieved significantly higher implantation rates, and clinical and ongoing pregnancy rates than the conventional group in both the ITT and PP analyses (P < 0.05). The two groups did not show significant differences between the number of oocytes retrieved or mature oocytes, two-pronuclear zygote (2PN) rates, the number of embryos obtained, blastocyst progression and good-quality embryo rates, early miscarriage rates, or OHSS incidence rates (P > 0.05).

LIMITATIONS, REASONS FOR CAUTION

A limitation of our study was that the subjects were not blinded to the treatment allocation in the RCT trial. Only women under 40 years of age who had a good prognosis were included in the analysis. Therefore, use of the modified antagonist protocol in older patients with a low ovarian reserve remains to be investigated. In addition, the sample size for Day 5 elective SET was small, so larger trials will be required to strengthen these findings.

WIDER IMPLICATIONS OF THE FINDINGS

The modified GnRH antagonist protocol using the Gn step-down approach and cessation of GnRH antagonist on hCG day improved the LBRs per fresh eSET cycle in normal responders.

STUDY FUNDING/COMPETING INTEREST(S)

This project was funded by grant 2022YFC2702503 from the National Key Research & Development Program of China and grant 2021140 from the Beijing Health Promotion Association. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

The RCT was registered in the Chinese Clinical Trial Registry; Study Number: ChiCTR2100053453.

TRIAL REGISTRATION DATE

21 November 2021.

DATE OF FIRST PATIENT’S ENROLLMENT

23 November 2021.

LH level on the antagonist administration day as a predictor of the reproductive outcomes in women with normal ovarian function

Introduction

The addition of antagonists is mainly based on estrogen level and follicle size, while LH level has not received sufficient attention.In this study, LH Level on the antagonist administration day was used as the main research objective to explore its relationship with laboratory indicators and pregnancy outcomes.

Methods and Analysis

We enrolled 854 patients with normal ovarian function undergoing in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) between May 2021 to May 2022 at the Reproductive Center of Shandong University of Traditional Chinese Medicine.We used the quartile method to group LH levels on the antagonist administration day. There were four groups: Q1 (0.53IU/L≤LH ≤ 1.89IU/L); Q2 (1.89IU/L

Result

There were significant differences among the four groups in terms of total Gn dosage, E2, P and LH on trigger day, number of retrieved oocytes, number of 2PN embryos, number of blastocysts, Number of ET and fresh ETR.There is a significant correlation between LH on antagonist administration day and Basal LH Level,LH on trigger day,number of oocytes retrieved,number of 2PN embryos,number of blastocysts, number of ET.Using Fresh ETR,Fresh CPR,OHSS and Cumulative CPR as the criterion respectively, the optimal cut-off value for evaluating LH on antagonist administration day was 4.18IU/L,3.99IU/L,4.63IU/L,4.66IU/L.

Conclusion

There was a significant positive correlation between LH on the antagonist administration day and number of oocytes retrieved,number of 2PN embryos,number of blastocysts.LH on the antagonist administration day could predict Fresh CPR,OHSS and Cumulative CPR to some extent.

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Key Words

• GnRH antagonist protocol
• LH level
• antagonist administration day
• laboratory indicators
• pregnancy outcomes

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MESH Headings

• Male
• Pregnancy
• Female
• Humans
• Gonadotropin-Releasing Hormone
• Ovulation Induction/methods
• Semen
• Fertilization in Vitro/methods
• Ovary

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Affiliation(s)

Conghui Pang The First Clinical College, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China Department of Reproduction and Genetics, The Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
Kehua Wang Department of Reproduction and Genetics, The Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
Ruihan Wang The First Clinical College, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
Danyang Guo The First Clinical College, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
Zixi Wen The First Clinical College, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China

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The effect of flexible low-dose GnRH antagonist on pregnancy outcome in the fresh embryo transfer cycle of IVF-ET: a randomized controlled trial

OBJECTIVE

To explore the practicality and effectiveness of a flexible low-dose protocol in the fresh embryo transfer cycle: reducing the total amount of antagonist by increasing the interval between administrations of Cetrotide.

METHODS

A total of 211 patients with normal ovarian reserve who accepted GnRH-ant protocol for IVF-ET were selected, and they were randomized to the flexible low-dose antagonist group (test group, n = 101) or the conventional dose antagonist group (control group, n = 110). The initial dose of Cetrotide in the test group was 0.25 mg every other day, and then the dose was adjusted to 0.25 mg every day based on the subsequent luteinizing hormone (LH) levels. The dosage of Cetrotide in the control group was 0.25 mg per day. The primary outcome was the clinical pregnancy rate. Secondary outcomes included the incidence of premature LH rise, total dosage of Cetrotide, number of oocytes retrieved, number of fertilized oocytes, number of high-quality embryos, biochemical pregnancy rate and ongoing pregnancy rate.

RESULTS

There was no significant difference in the general condition of the two groups. There was no significant difference in the clinical pregnancy rate (51.49% vs. 48.18%, p = 0.632) or the incidence of premature LH rise (18.81% vs. 15.45%, p = 0.584) between the two groups. However, the amount of Cetrotide used in the test group was significantly lower than that in the conventional dose antagonist group (1.13 ± 0.41 vs. 1.61 ± 0.59 mg, p < 0.001).

CONCLUSION

The flexible low-dose antagonist protocol and the conventional dose antagonist protocol were equally effective in people with a normal ovarian reserve in the fresh embryo transfer cycle of IVF-ET.

Endometrial preparation for women undergoing embryo transfer with frozen embryos or embryos derived from donor oocytes

BACKGROUND

A frozen embryo transfer (FET) cycle is when one or more embryos (frozen during a previous treatment cycle) are thawed and transferred to the uterus. Some women undergo fresh embryo transfer (ET) cycles with embryos derived from donated oocytes. In both situations, the endometrium is primed with oestrogen and progestogen in different doses and routes of administration.

OBJECTIVES

To evaluate the most effective endometrial preparation for women undergoing transfer with frozen embryos or embryos from donor oocytes with regard to the subsequent live birth rate (LBR).

SEARCH METHODS

The Cochrane Gynaecology and Fertility Group trials register, CENTRAL, MEDLINE, Embase, PsycINFO, LILACS, trials registers and abstracts of reproductive societies' meetings were searched in June 2020 together with reference checking and contact with study authors and experts in the field to identify additional studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating endometrial preparation in women undergoing fresh donor cycles and frozen embryo transfers.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. We analysed all available interventions versus placebo, no treatment, or between each other. The primary review outcome was live birth rate. Secondary outcomes were clinical and multiple pregnancy, miscarriage, cycle cancellation, endometrial thickness and adverse effects.

MAIN RESULTS

Thirty-one RCTs (5426 women) were included. Evidence was moderate to very low-quality: the main limitations were serious risk of bias due to poor reporting of methods, and serious imprecision. Stimulated versus programmed cycle We are uncertain whether a letrozole-stimulated cycle compared to a programmed cycle, for endometrial preparation, improves LBR (odds ratio (OR) 1.26, 95% confidence interval (CI) 0.49 to 3.26; 100 participants; one study; very low-quality evidence). Stimulating with follicle stimulating hormone (FSH), letrozole or clomiphene citrate may improve clinical pregnancy rate (CPR) (OR 1.63, 95% CI 1.12 to 2.38; 656 participants; five studies; I² = 11%; low-quality evidence). We are uncertain if they reduce miscarriage rate (MR) (OR 0.79, 95% CI 0.36 to 1.71; 355 participants; three studies; I² = 0%; very low-quality evidence). Endometrial thickness (ET) may be reduced with clomiphene citrate (mean difference(MD) -1.04, 95% CI -1.59 to -0.49; 92 participants; one study; low-quality evidence). Other outcomes were not reported. Natural versus programmed cycle We are uncertain of the effect from a natural versus programmed cycle for LBR (OR 0.97, 95% CI 0.74 to 1.28; 1285 participants; four studies; I² = 0%; very low-quality evidence) and CPR (OR 0.79, 95% CI 0.62 to 1.01; 1249 participants; five studies; I² = 60%; very low-quality evidence), while a natural cycle probably reduces the cycle cancellation rate (CCR) (OR 0.60, 95% CI 0.44 to 0.82; 734 participants; one study; moderate-quality evidence). We are uncertain of the effect on MR and ET. No study reported other outcomes. Transdermal versus oral oestrogens From low-quality evidence we are uncertain of the effect transdermal compared to oral oestrogens has on CPR (OR 0.86, 95% CI 0.59 to 1.25; 504 participants; three studies; I² = 58%) or MR (OR 0.55, 95% CI 0.27 to 1.09; 414 participants; two studies; I² = 0%). Other outcomes were not reported. Day of starting administration of progestogen When doing a fresh ET using donated oocytes in a synchronised cycle starting progestogen on the day of oocyte pick-up (OPU) or the day after OPU, in comparison with recipients that start progestogen the day prior to OPU, probably increases the CPR (OR 1.87, 95% CI 1.13 to 3.08; 282 participants; one study, moderate-quality evidence). We are uncertain of the effect on multiple pregnancy rate (MPR) or MR. It probably reduces the CCR (OR 0.28, 95% CI 0.11 to 0.74; 282 participants; one study; moderate-quality evidence). No study reported other outcomes. Gonadotropin-releasing hormone (GnRH) agonist versus control A cycle with GnRH agonist compared to without may improve LBR (OR 2.62, 95% CI 1.19 to 5.78; 234 participants; one study; low-quality evidence). From low-quality evidence we are uncertain of the effect on CPR (OR 1.08, 95% CI 0.82 to 1.43; 1289 participants; eight studies; I² = 20%), MR (OR 0.85, 95% CI 0.36 to 2.00; 828 participants; four studies; I² = 0%), CCR (OR 0.49, 95% CI 0.21 to 1.17; 530 participants; two studies; I² = 0%) and ET (MD -0.08, 95% CI -0.33 to 0.16; 697 participants; four studies; I² = 4%). No study reported other outcomes. Among different GnRH agonists From very low-quality evidence we are uncertain if cycles among different GnRH agonists improves CPR or MR. No study reported other outcomes. GnRH agonists versus GnRH antagonists GnRH antagonists compared to agonists probably improves CPR (OR 0.62, 95% CI 0.42 to 0.90; 473 participants; one study; moderate-quality evidence). We are uncertain of the effect on MR and MPR. No study reported other outcomes. Aspirin versus control From very low-quality evidence we are uncertain whether a cycle with aspirin versus without improves LBR, CPR, or ET. Steroids versus control From very low-quality evidence we are uncertain whether a cycle with steroids compared to without improves LBR, CPR or MR. No study reported other outcomes.

AUTHORS' CONCLUSIONS

There is insufficient evidence on the use of any particular intervention for endometrial preparation in women undergoing fresh donor cycles and frozen embryo transfers. In frozen embryo transfers, low-quality evidence showed that clinical pregnancy rates may be improved in a stimulated cycle compared to a programmed one, and we are uncertain of the effect when comparing a programmed cycle to a natural cycle. Cycle cancellation rates are probably reduced in a natural cycle. Although administering a GnRH agonist, compared to without, may improve live birth rates, clinical pregnancy rates will probably be improved in a GnRH antagonist cycle over an agonist cycle. In fresh synchronised oocyte donor cycles, the clinical pregnancy rate is probably improved and cycle cancellation rates are probably reduced when starting progestogen the day of or day after donor oocyte retrieval. Adequately powered studies are needed to evaluate each treatment more accurately.

GnRH antagonist versus follicular-phase single-dose GnRH agonist protocol in patients of normal ovarian responses during controlled ovarian stimulation

OBJECTIVE

This study aims to explore the differences of the ovarian stimulation (OS) characteristics, laboratory, and clinical outcomes between follicular-phase single-dose gonadotropin-releasing hormone (GnRH) agonist protocol and GnRH antagonist protocol during controlled ovarian hyperstimulation (COH).

METHODS

About 1883 consecutive IVF/ICSI fresh cycles of normal ovarian responders were retrospectively analyzed, with 1229 in the single-dose GnRH agonist protocol group and 654 in the GnRH antagonist protocol group at Reproductive Medical Center of Tongji Hospital from 1 January 2014 to 31 December 2017.

RESULTS

The follicular-phase single-dose GnRH agonist group showed significantly more oocytes obtained, higher implantation rate and pregnancy rate, as well as lower luteinizing hormone (LH) level and estradiol (E2)/oocyte ratio on the day of human chorionic gonadotropin (hCG) administration. However, differences were not significant in meiosis II (MII) oocyte rate, two pronuclear zygote (2PN) embryo rate, viable embryo rate or high-quality embryo rate, compared with the GnRH antagonist group. Further comparison of clinical outcomes in the first frozen-thawed cycles did not show significant difference in either implantation or clinical pregnancy rate between the two protocol groups.

CONCLUSIONS

Follicular-phase single-dose GnRH agonist protocol may achieve better clinical outcomes in normal ovarian responders, which could be explained more by positive effect on endometrial receptivity rather than embryo quality.

GnRH antagonist for endometrial priming in an oocyte donation programme: a prospective, randomized controlled trial

RESEARCH QUESTION

Can gonadotrophin releasing hormone (GnRH) antagonist be used in egg donation recipients with ovulatory cycles for the purpose of achieving synchronization between the donor´s and recipient´s cycle?

DESIGN

Prospective randomized controlled trial to compare 7-day dosage of GnRH antagonist for endometrial priming in an oocyte donation programme with a single dose of long-acting GnRH agonist. A total of 563 women were randomized in a private single centre, and 473 women underwent embryo transfer. Ongoing pregnancy rate was the primary end point. Analysis was adjusted for embryonic stage at the time of embryo transfer; data collected included days on the waiting list; number of fresh-vitrified oocytes collected; and oocyte donor´s age at the time of retrieval.

RESULTS

No statistically significant differences were found between groups in per intention-to-treat analysis: adjusted OR 1.42 (CI 0.97 to 2.09); per treatment received: adjusted OR 1.43 (CI 0.97 to 2.09); per embryo transfer: adjusted OR for ongoing pregnancy rate 1.47 (CI 1.01 to 2.13), P = 0.047.

CONCLUSIONS

For women with ovulatory cycles undergoing oocyte donation, the outcomes are similar between GnRH antagonist and down-regulated hormone replacement protocols.

Increased Uterine NK cell numbers and perforin expression during the implantation phase in IVF Cycles with GnRH Antagonist Protocol

GnRH antagonist negatively affects endometrial receptivity in in vitro fertilization (IVF) cycles, however, its underlying mechanism remains unclear. To explore its target molecules, we studied endometria in the window phase of fixed GnRH antagonist, low-dose flexible GnRH antagonist, GnRH agonist long protocol, and untreated control groups. There were 384 differentially expressed genes (DEGs) in the fixed antagonist group with greater than twofold expression change compared with the control group and 197 DEGs between the fixed antagonist and agonist groups, the majority of which were associated with the natural killer (NK) cell-mediated cytotoxicity pathway. We then analysed the PRF1 and FASLG protein levels. The perforin level were significantly higher in both the antagonist groups than in other two groups, and was higher in the fixed antagonist group. Similarly, the uNK cell numbers were higher in the antagonist groups, and the highest uNK cell number occurred in the fixed group (p < 0.05). No significant differences existed in the Fas ligand levels and apoptosis rates among the three treatment groups, but were higher in the treatment groups than the control group. Together, these data indicate that GnRH antagonist may increase the uNK cell numbers and perforin expression, and this effect may be dose-dependent.

New Perspectives on Criteria for the Determination of HCG Trigger Timing in GnRH Antagonist Cycles

The aim of this study was to investigate 2 quantification criteria to evaluate the developmental condition of follicles cohort and clarify their impacts upon the determining of human chorionic gonadotropin trigger timing and the reproductive outcome: the proportion of mature follicles in growing follicles cohort on the day of human chorionic gonadotropin trigger and the peak estradiol level per oocyte on the day of human chorionic gonadotropin administration.Of the patients who underwent in vitro fertilization/ intracytoplasmic sperm injection-embryo transfer from 2011 to 2013, 492 controlled ovarian hyperstimulation cycles using gonadotropin-releasing hormone antagonists reaching the ovum pick-up and fresh embryo-transfer stage were included. Patients were divided into 3 groups according to their ≥17 mm/≥10 mm follicles ratio on the day of human chorionic gonadotropin administration (Low proportion: ≤30%, Middle proportion: 30%-60%, High proportion: ≥60%). Patients were divided into 5 groups according to their peak estradiol level/oocyte (Group A: <100 pg/mL per oocyte, Group B: 100-199 pg/mL per oocyte, Group C: 200-299 pg/mL per oocyte, Group D: 300-399 pg/mL per oocyte, Group E ≥400 pg/mL per oocyte) as well. Comparison among groups was made regarding ovarian stimulation characteristics, fertilization rate, good quality embryo rate, implantation, pregnancy, and live birth rates.On the basis of ≥17 mm/≥10 mm follicles ratio, the number of oocyte retrieved in low proportion group is more than other 2 groups. Implantation rate, clinical pregnancy, and live birth rate in high proportion group were 25.8%, 42.7%, and 31.1%, respectively, which is highest in 3 groups, and statistical significance existed between high and middle proportion groups. When the division is based on peak estradiol level/oocyte, the number of oocyte retrieved of ≥400 pg/mL per oocyte Group was significantly lowest compared with the other 4 groups. Matured ovum rate, fertilization rate, and good quality embryos rate exhibited an increasing trend as the peak estradiol level/oocyte increased. While pregnancy rate, implantation rate, and live birth rate were found to be lower whenever estradiol/oocyte ratio exceeded 400 pg/mL per oocyte or less than 100 pg/mL per oocyte, and there is statistical difference.Patients with the proportion of mature follicle reaching 60% on the day of human chorionic gonadotropin trigger and peak estradiol/oocyte level within 100∼399 pg/mL range can get a better pregnancy and implantation rate.

Does the use of gonadotropin-releasing hormone antagonists in natural IVF cycles for poor responder patients cause more harm than benefit?

Poor ovarian response to controlled ovarian stimulation (COS) is one of the most critical factors that substantially limits the success of assisted reproduction techniques (ARTs). Natural and modified natural cycle IVF are two options that could be considered as a last resort. Blocking gonadotropin-releasing hormone (GnRH) actions in the endometrium via GnRH receptor antagonism may have a negative impact on endometrial receptivity. We analysed IVF outcomes in 142 natural (n = 30) or modified natural (n = 112) IVF cycles performed in 82 women retrospectively. A significantly lower proportion of natural cycles reached follicular aspiration compared to modified natural cycles (56.7% vs. 85.7%, p < 0.001). However, the difference between the numbers of IVF cycles ending in embryo transfer (26.7% vs. 44.6%) was not statistically significant between natural cycle and modified natural IVF cycles. Clinical pregnancy (6.7% vs. 7.1%) and live birth rates per initiated cycle (6.7% vs. 5.4%) were similar between the two groups. Notably, the implantation rate was slightly lower in modified natural cycles (16% vs. 25%, p > 0.05). There was a trend towards higher clinical pregnancy (25% vs. 16%) and live birth (25% vs. 12%) rates per embryo transfer in natural cycles compared to modified natural cycles, but the differences did not reach statistical significance.

Dual trigger with combination of gonadotropin-releasing hormone agonist and human chorionic gonadotropin significantly improves the live-birth rate for normal responders in GnRH-antagonist cycles

OBJECTIVE

To investigate whether dual triggering of final oocyte maturation with a combination of gonadotropin-releasing hormone (GnRH) agonist and human chorionic gonadotropin (hCG) can improve the live-birth rate for normal responders in GnRH-antagonist in vitro fertilization/intracytoplasmic sperm injection (IVF-ICSI) cycles.

DESIGN

Retrospective cohort study.

SETTING

Infertility unit of a university-affiliated medical center.

PATIENT(S)

Normal responders to controlled ovarian hyperstimulation who were undergoing IVF-ICSI with a GnRH antagonist protocol.

INTERVENTION(S)

Standard dosage of hCG trigger (6,500 IU of recombinant hCG) versus dual trigger (0.2 mg of triptorelin and 6,500 IU of recombinant hCG).

MAIN OUTCOME MEASURE(S)

Live-birth, clinical pregnancy, and implantation rates per cycle.

RESULT(S)

A total of 376 patients with 378 completed cycles with embryo transfer were enrolled (hCG trigger/control group: n = 187; dual trigger/study group: n = 191). The dual trigger group demonstrated statistically significantly higher implantation (29.6% vs. 18.4%), clinical pregnancy (50.7% vs. 40.1%), and live-birth (41.3% vs. 30.4%) rates as compared with the hCG trigger group. There was no statistically significant difference in terms of patient demographics, cycle parameters, or embryo quality.

CONCLUSION(S)

Dual trigger of final oocyte maturation with a GnRH-agonist and a standard dosage of hCG in normal responders statistically significantly improves implantation, clinical pregnancy, and live-birth rates in GnRH-antagonist IVF cycles.

HOXA10 protein expression in the endometrium of normally menstruating women after receiving GnRH antagonist

OBJECTIVE(S)

To compare HOXA10 protein expression in the endometrium between natural control cycles and GnRH antagonist-treated cycles obtained during the window of implantation of normally menstruating women.

STUDY DESIGN

This study was conducted at the Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. Thirty-five volunteers were recruited into this prospective, self-controlled study, which was divided into two cycles, the first a natural control cycle and the second a GnRH antagonist-treated cycle. The two cycles were separated by one resting cycle. In the GnRH antagonist-treated cycle, when the leading follicle was 15 mm, ganirelix (Orgalutran®) 0.25mg was administered daily. In both cycles, ovulation was induced when the largest follicle reached 18 mm in diameter. Finally, endometrial biopsy was performed on day 6 after documented ovulation, which corresponds to the window of implantation. Endometrial HOXA10 protein expression, a marker of endometrial receptivity, was analyzed by immunohistochemistry. The protein expression was compared between the two cycles regarding their percentage of immunostained cells and IHC-scores (percentage of stained cells×intensity of nuclear staining).

RESULTS

HOXA10 protein was exclusively localized in the stromal compartment of the endometrium. The percentage of HOXA10 nuclear staining in the endometrium collected from GnRH antagonist-treated cycles was higher than that of the natural cycles, whereas the IHC-scores showed no difference between the two cycles.

CONCLUSION(S)

GnRH antagonists may have no effect on HOXA10 protein expression in the endometrium obtained during the implantation window of normally menstruating women.

Optimal usage of the GnRH antagonists: a review of the literature

Gonadotropin-releasing hormone (GnRH) antagonists, which became commercially available from 1999, have been used for the prevention of premature luteinizing hormone (LH) surges in controlled ovarian stimulation for in vitro fertilization or intracytoplasmic sperm injection. This review focuses on the recent literature on the use of GnRH antagonists and provides guidelines for optimal use in light of increasing evidence showing that GnRH antagonists are safe and effective, allowing flexibility of treatment in a wide range of patient populations. This includes patients undergoing first-line controlled ovarian stimulation, poor responders, and women diagnosed with polycystic ovary syndrome. The GnRH antagonist offers a viable alternative to the long agonists, providing a shorter duration of treatment with fewer injections and with no adverse effects on assisted reproductive technology outcome. This results in a significantly lower amount of gonadotropins required, which is likely to lead to improved patient compliance.

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.

Gonadotrophin ovulation induction and enhancement outcomes: analysis of more than 1400 cycles

Ovulation induction (OI) or ovulation enhancement (OE) with gonadotrophins can be a reasonable treatment option for patients with a variety of infertility diagnoses. It must be used with extensive monitoring and management given the risk of multiple pregnancy,especially high-order multiples. This retrospective study evaluated per cycle outcomes of a large cohort of 1452 gonadotrophin OI/OE cycles at an academic infertility centre, and the efficacy of specific guidelines in limiting multiple pregnancy. The lowest possible gonadotrophin doses were used and cycle cancellation was recommended if more than three dominant follicles were present, and/or ifserum oestradiol was above 1500 pg/ml. Overall, pregnancy rate (PR) was 12% and live birth rate was 7.7%, with an increasing trend in younger patients (P = 0.0002 and <0.0001, respectively). Multiple clinical PR was 2.6% with 1.9% twins and 0.7% triplets and above.The birthweight of a singleton from a vanishing twin pregnancy (n = 8)was significantly lower than other singletons (2882 g versus 3250 g,P = 0.013). Reducing multiple pregnancies from OI/OE cycles remains an important and challenging goal. In this large cohort, high-order multiple clinical PR was limited to 0.7% per cycle by using specific management strategies while maintaining a reasonable PR.

The relationship between endometrial thickness and pregnancy rates in GnRH antagonist down-regulated ICSI cycles

OBJECTIVE

To investigate the effects of endometrial thickness measurements and serum hormone levels on the outcomes of GnRH antagonist down-regulated ICSI cycles.

STUDY DESIGN

Forty consecutive infertile women undergoing controlled ovarian hyperstimulation with recombinant FSH and GnRH antagonists for ICSI were enrolled in this study. All patient's age, day 3 FSH, antral follicle count (AFC), serum E2 levels on day 3, E2 on stimulation day 5, E2 on day of hCG administration, endometrial thickness on the baseline (ETMBaseline), on day 5 of stimulation (ETMDay 5), on day of hCG administration (ETMhCG) and cycle outcomes were recorded. The outcomes of pregnant and nonpregnant women were compared.

RESULTS

Women's age was 33.6 +/- 4.9. Overall pregnancy rate was 45% (n = 18), clinical pregnancy rate was 27.5% (n = 11) and ongoing pregnancy rate was 20% (n = 8). In pregnant women, baseline AFC was significantly higher compared with nonpregnant women (p = 0.01). There was no significant correlation between ETMhCG and E2 level on the day of hCG, number of retrieved oocytes or patients' age.

CONCLUSION

For achieving pregnancy, endometrial thickness on the day of hCG is not a determining parameter, and the only significant determinent is AFC in GnRH antagonist down-regulated ICSI cycles.

Endometrial preparation for women undergoing embryo transfer with frozen embryos or embryos derived from donor oocytes

BACKGROUND

If a fresh embryo, assisted reproductive technology procedure cycle is unsuccessful and there are frozen embryos available, a frozen-thawed embryo transfer is performed. In some specific cases women may undergo oocyte donation treatment. In both situations the endometrium is primed by the administration of estrogen and progesterone. To prevent the possibility of spontaneous ovulation, gonadotropin-releasing hormone (GnRH) agonists are frequently used.

OBJECTIVES

To evaluate the most effective endometrial preparation for women undergoing transfer with frozen embryos or embryos from donor oocytes with regard to the subsequent live birth rate.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, LILACS, and abstracts of reproductive societies' meetings (from inception). No language restrictions were applied. Experts in the field were contacted.

SELECTION CRITERIA

Randomised controlled trials evaluating endometrial preparation in women undergoing fresh donor cycles and frozen embryo transfers.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, assessed trial risk of bias, and extracted data.

MAIN RESULTS

Twenty two randomised controlled trials were included. Five studies analysed the use of a GnRH agonist versus control. No significant benefit was demonstrated when using GnRH agonists. No evidence of statistically significant benefit was found for one GnRH agonist over another, or vaginal over intramuscular progesterone administration. No difference in pregnancy rate was demonstrated when no treatment was compared to aspirin, steroids, ovarian stimulation, or human chorionic gonadotropin (hCG) prior to embryo transfer, although using hCG several times before the oocyte retrieval decreases the pregnancy rate. Finally, when oocyte recipients were studied further, starting progesterone on the day of oocyte pick-up (OPU) or the day after OPU produced a significantly higher pregnancy rate (OR 1.87, 95% CI 1.13 to 3.08) than when recipients started progesterone the day prior to OPU.

AUTHORS' CONCLUSIONS

There is insufficient evidence to recommend any one particular protocol for endometrial preparation over another with regard to pregnancy rates after embryo transfers. These were either frozen embryos or embryos derived from donor oocytes. However, there is evidence of a lower pregnancy rate and a higher cycle cancellation rate when the progesterone supplementation is commenced prior to oocyte retrieval in oocyte donation cycles. Adequately powered studies are needed to evaluate each treatment more accurately.

GnRH antagonist, cetrorelix, for pituitary suppression in modern, patient-friendly assisted reproductive technology

BACKGROUND

Gonadotropin-releasing hormone (GnRH) analogues are used routinely to prevent a premature luteinizing hormone (LH) surge in women undergoing assisted reproductive technology (ART) treatments. In contrast to GnRH agonists, antagonists produce rapid and reversible suppression of LH with no initial flare effect.

OBJECTIVE

To review the role of cetrorelix, the first GnRH antagonist approved for the prevention of premature LH surges during controlled ovarian stimulation in modern ART.

METHOD

A review of published literature on cetrorelix.

RESULTS

Both multiple- and single-dose cetrorelix protocols were shown to be at least as effective as long GnRH agonist regimens for pituitary suppression in Phase II/III clinical trials. Furthermore, cetrorelix co-treatment resulted in similar live birth rates but a shorter duration of gonadotropin stimulation, a lower total gonadotropin dose requirement and lower incidence of ovarian hyperstimulation syndrome compared with long agonist regimens. A single-dose cetrorelix protocol further decreased the number of injections required. Preliminary studies have also produced promising data on the use of cetrorelix in modified ART protocols, such as frozen embryo transfer and donor oocyte recipient cycles.

CONCLUSION

Cetrorelix offers a potential therapeutic alternative to GnRH agonists during controlled ovarian stimulation and has become an integral part of modern, patient-friendly reproductive medicine.