Embryo implantation and GnRH antagonists: GnRH antagonists in ART: lower embryo implantation?

Trade-off between double cleavage-stage embryos transfer and single blastocyst-stage embryo transfer in patients with few good quality embryos in antagonist cycles: a retrospective study using a propensity score matching analysis

OBJECTIVE

This study aimed to compare the per OPU clinical outcomes for transfer of Day 3 double cleavage-stage embryos (DET) and Day 5 single blastocyst-stage (SBT) in patients with five or fewer good quality embryos on day 3 per occyte pick-up cycle (OPU) in antagonist cycles with consideration of blastocyst formation failure.

METHODS

This was a retrospective, observational cohort study of 2,116 cases of OPU treated with antagonist protocol in the affiliated Chenggong Hospital of Xiamen University between January 2013 and December 2020. DET was performed in 1,811cycles and SBT was performed in 305 cycles. The DET group was matched to the SBT group by propensity score (PS) matching according to multiple maternal baseline covariates. After PS matching, there were 303 ET cycles in each group. The primary outcomes were the cumulative live birth rate (CLBR), cumulative multiple pregnancy rate(CMPR)per OPU and the number of ET to achieve live birth per OPU. Secondary outcomes were the percentage of clinical pregnancy(CPR), live birth rate(LBR), multiple pregnancy rate(MPR).

RESULTS

Following PS mating, the CLBR was slightly higher (48.8% versus 40.3% ; P = 0.041) and the CMPR was significantly higher in the DET group compared to SBT group(44.2% versus 7.9%, P < 0.001). The CPR, LBR and MPR per fresh transfer were higher in DET group compared to SBT group(50.2% versus 28.7%; 41.3% versus 21.5%;29.6% versus 0%, P < 0.001). The number of ET to achieve live birth per OPU in SBT group was obiviously more than in DET group(1.48 ± 0.578 versus 1.22 ± 0.557 ,P < 0.001).

CONCLUSION

With a marginal difference cumulative live birth rate, the lower live birth rate per fresh transfer and higher number of ET per OPU in the SBT group suggested that it might take longer time to achieve a live birth with single blastocyst strategy. A trade-off decision should be made between efficiency and safety.

Effect of GnRH analogues for pituitary suppression on oocyte morphology in repeated ovarian stimulation cycles

OBJECTIVE

To compare the effect of pituitary suppression regimens on oocyte morphology in consecutive ICSI cycles of the same patients.

METHODS

Data was obtained from 200 matched consecutive intracytoplasmic sperm injection (ICSI) cycles performed in 100 couples undergoing the first cycle with the GnRH agonist and the following cycle with the GnRH antagonist regimen, from January 2010 to August 2016, in a private university-affiliated IVF centre. The effects of the pituitary suppression type on oocyte morphology were assessed by multivariate General Linear Models.

RESULTS

Mean interval between cycles was 185.32±192.85 days. Maternal age, body mass index, and total FSH dose administered were similar in both patients' cycles. Antagonist cycles presented lower incidence of dark cytoplasm (0.69±3.28% vs. 4.40±17.70%, p=0.047), Smooth endoplasmic reticulum (SER cluster (4.37±11.62% vs. 7.36±17.17%, p=0.046), and ZP defects (6.05±14.76% vs. 11.84±25.13%, p=0.049). Similar numbers of follicles retrieved oocytes, and mature oocytes were observed between the GnRH groups, as well as the fertilisation rate, number of obtained embryos, high-quality embryo rates, and the clinical outcomes.

CONCLUSION

GnRH antagonist's inhibitory effect on the ovaries in consecutive ICSI cycles results in improved oocyte maturity and morphology, despite similar laboratory and clinical outcomes, compared to the GnRH agonist treatment.

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.

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.

The role of GnRH antagonists in assisted reproduction

The different schemes of application of gonadotrophin-releasing hormone (GnRH) antagonists in ovarian stimulation protocols for assisted reproduction are reviewed. Starting from the initial schemes of single and/or multiple doses, the efficacy of GnRH antagonists in 'soft' protocols of ovarian stimulation has been evaluated in natural cycles, and the possibility of inducing the final oocyte maturation under antagonists either with native luteinizing hormone-releasing hormone or with GnRH agonists. The largest clinical studies carried out with cetrorelix or with ganirelix and published to date were analysed. Apart from the benefits of reducing the duration of the treatment, gonadotrophin requirements and ovarian hyperstimulation syndrome incidence, there is still a serious debate on the potential deleterious effect of GnRH antagonists on implantation and pregnancy rates. More specific aspects such as cycle programming, application of GnRH antagonists in protocols for poor responders etc., were also reviewed in this survey.

Low-dose GnRH antagonist protocol is as effective as the long GnRH agonist protocol in unselected patients undergoing in vitro fertilization and embryo transfer

OBJECTIVE

The present retrospective and controlled comparative study was designed to evaluate the pregnancy rate achieved using a modified, fixed, multiple-dose 0.125mg gonadotropin-releasing hormone (GnRH) antagonist protocol with the long GnRH agonist protocol as the control group.

MATERIALS AND METHODS

One hundred and twenty unselected women between 30 and 40 years of age, in their first cycle of IVF/ICSI, with a baseline follicle-stimulating hormone (FSH) <10 IU and an antral follicle count >3 were assigned into two groups: (1) the study group received 0.125mg of cetrorelix daily starting on Day 6 of stimulation; and (2) the control group received leuprolide daily starting in the mid-luteal phase of the preceding cycle. Both groups were given a flexible dose of recombinant FSH for stimulation. An ongoing pregnancy rate of more than 12 weeks was the primary outcome measure of the study.

RESULTS

Primary and secondary outcomes were comparable in both groups. A shorter duration of stimulation, a lower dosage of recombinant FSH consumption and a thinner endometrium on the day of human chorionic gonadotropin administration were all observed in the GnRH antagonist group.

CONCLUSION

A dosage of 0.125mg GnRH antagonist protocol was effective for these unselected patients during IVF/ET.

Drug delivery for in vitro fertilization: rationale, current strategies and challenges

In vitro fertilization has experienced phenomenal progress in the last thirty years and awaits the additional refinement and enhancement of medication delivery systems. Opportunity exists for the novel delivery of gonadotropins, progesterone and other adjuvants. This review highlights the rationale for various medications, present delivery methods and introduces the status of novel ideas and possibilities.

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.

Gonadotropin-releasing hormone antagonists increase follicular fluid insulin-like growth factor-I and vascular endothelial growth factor during ovarian stimulation cycles

The aim of the present study was to investigate the effect of gonadotropin-releasing hormone (GnRH) antagonists (GnRH-ant) on follicular fluid (FF) insulin-like growth factor-I (IGF-I) and FF vascular endothelial growth factor (VEGF) levels. Sixty women undergoing assisted reproduction were randomized and assigned to two different GnRH analog regimens: GnRH agonist (GnRH-a) and GnRH-ant. FF VEGF and FF IGF-I concentrations were significantly increased in the patients treated with GnRH-ant (p < 0.001). In the same patients we observed a statistically significant reduction in serum luteinizing hormone (LH) and estradiol (E2) levels (p < 0.001 and p < 0.05, respectively), FF E2 and FF androstenedione levels (p < 0.05 and p < 0.001, respectively), as well as a reduction in the number of pregnancies although this was not statistically significant. In the GnRH-ant group, FF VEGF levels were positively correlated with FF IGF-I levels, and both were negatively correlated with serum LH levels. The increase in FF IGF-I and FF VEGF levels in women treated with GnRH-ant could be explained by a deleterious follicular environment in response to profound suppression of LH and E2 levels.

Follicular fluid vascular endothelial growth factor concentrations are increased during GnRH antagonist/FSH ovarian stimulation cycles

BACKGROUND

The aim of this study was to investigate the effect of GnRH antagonists (GnRH-ant) on follicular fluid vascular endothelial growth factor (FF VEGF).

METHODS

Sixty women undergoing assisted reproduction were randomised (computer-generated randomisation list) and assigned to two different GnRH analogue regimens: GnRH agonist (GnRH-a) (Group A; n = 30) and GnRH-ant (Group B; n = 30).

RESULTS

Mean (+/-S.D.) FF VEGF concentrations were 1598+/-612 pg/mL and 2906+/-1558 pg/mL for Groups A and B, respectively (p < 0.001). In the women treated with GnRH-ant, we found a statistically significant reduction in serum LH levels (1.72+/-0.74 IU/L in Group A versus 0.93+/-0.43 IU/L in Group B, p < 0.001), in serum oestradiol (E2) levels (1562.1+/-410.7 pg/mL in Group A versus 1214.67+/-779.9 pg/mL in Group B, p < 0.05), in FF E2 levels (1146+/-593 ng/mL in Group A versus 621+/-435 ng/mL in Group B, p < 0.05), and in FF androstenedione levels (136+/-55 ng/mL in Group A versus 78+/-31 ng/mL in Group B, p < 0.001), as well as a reduction in the number of pregnancies, though not statistically significant (23.3% in Group A versus 16.6% in Group B).

CONCLUSION

The increase in FF VEGF levels in women treated with GnRH-ant might be explained by a suppression of LH and E2 levels.

Precycle administration of GnRH antagonist and microdose HCG decreases clinical pregnancy rates without affecting embryo quality and blastulation

The outcome of a novel protocol utilizing precycle gonadotrophin-releasing hormone (GnRH) antagonist administration and LH activity support with microdose recombinant human chorionic gonadotrophin (HCG) was compared to GnRH agonist long protocol used in patients undergoing their first ICSI (n=707) or IVF (n=571) cycles, which had resulted in one or two blastocyst transfers. In GnRH antagonist cycles, cetrorelix acetate (3 mg) was administered s.c. 4 days before FSH stimulation and a repeat dose was given when the lead follicular diameter was 13-14 mm. LH support was provided by recombinant HCG (2.5 microg). Embryo progression and blastulation were evaluated using embryo progression indices and blastocyst quality scores. The tested protocol demonstrated reduced implantation and clinical pregnancy rates as compared with GnRH agonist long protocol, although the embryo progression and blastulation parameters and blastocyst quality were comparable among the groups. Logistic regression models further supported the significant negative impact of GnRH antagonist/microdose HCG protocol on clinical pregnancy rates in both ICSI and IVF patients. Assisted reproduction cycles with fresh blastocyst transfers utilizing precycle GnRH antagonist administration and microdose HCG support resulted in lower implantation and clinical pregnancy rates as compared with GnRH agonist cycles, although the embryo progression and blastulation parameters were comparable.

A randomised study of GnRH antagonist (cetrorelix) versus agonist (busereline) for controlled ovarian stimulation: effect on safety and efficacy

OBJECTIVE

To assess safety and efficacy of cetrorelix utilisation in controlled ovarian stimulation (COS).

STUDY DESIGN

Phase III, randomized, single center study of 131 patients undergoing COS and IVF with or without ICSI, in a University affiliated Hospital. Sixty-six patients were allocated to the protocol with antagonist and 65 to the agonist protocol arm. The Student's t-test, the Mann-Whitney test and the chi-square test were applied as required, using SPSS for Windows with a two-sided 5% significance level.

RESULTS

The mean (+/-S.D.) duration of stimulation was 9.5+/-1.7 days in the antagonist group and 10.6+/-2.1 days in the agonist group (P=0.02). The mean (+/-S.D.) duration of suppression was 4.6+/-1.3 days in the antagonist group and 27.3+/-5.2 days in the agonist group (P<0.0001). No significant differences were noted in other outcome measures: amount of rFSH required, estradiol level on hCG day, number of follicles>or=15 mm and endometrial thickness on oocyte retrieval day, number of oocytes retrieved, fertilization rate and number of OHS cases. Clinical pregnancy rates per-attempt and per-transfer were 15.1% and 17.0% in the antagonist group and 16.9% and 20.0% in the agonist group (P=0.79 and 0.71, respectively).

CONCLUSIONS

GnRH antagonists are an effective, safe and well tolerated alternative to agonists for COS.

An oocyte donation protocol using the GnRH antagonist ganirelix acetate, does not compromise embryo quality and is associated with high pregnancy rates

PURPOSE

To evaluate the effect of the GnRH antagonist, ganirelix acetate, on oocyte quality.

METHODS

Stimulation characteristics, implantation rates and clinical pregnancy rates were compared between 29 oocyte donors 21-31 years of age who underwent 31 cycles of ovarian stimulation with gonadotropins and ganirelix acetate, and 36 infertile couples of similar age range who underwent 51 cycles of ovarian stimulation using the same protocol.

RESULTS

A significantly lower number of embryos were transferred in the donor/recipient group as compared to the infertile group (2.32+/-0.54 vs. 2.82+/-0.71, P<0.05). In contrast, implantation and clinical pregnancy rates per transfer, were significantly higher in the donor/recipient group (38.1% vs. 10.4%, P<0.01) and (61.3% vs. 23.1%, P<0.05) respectively, as compared to the infertile group.

CONCLUSIONS

Incorporation of ganirelix acetate for pituitary suppression in stimulation protocols for oocyte donation is associated with high pregnancy rates suggesting that ganirelix acetate does not exert an adverse effect on oocyte or embryo quality.

Luteinizing hormone supplementation increases pregnancy rates in gonadotropin-releasing hormone antagonist donor cycles

OBJECTIVE

To determine whether LH supplementation improved pregnancy and implantation rates in GnRH antagonist donor cycles.

DESIGN

Donors were randomly assigned to a protocol using GnRH antagonist (GnRH-a) alone or GnRH-a + recombinant LH. Analysis of variance, Student's t-test and Fisher's exact test were used where appropriate.

SETTING

Private clinical setting.

PATIENT(S)

Young voluntary donors with antagonist (n = 20) and antagonist + LH (n = 22). Fifty-five patients received oocytes.

INTERVENTION(S)

Donors received the GnRH-a (Cetrorelix, 0.25 mg/day) alone or in combination with recombinant LH (75 IU/day). Ovulation induction was carried out with recombinant FSH in a step-down protocol. The endometrial tissue of recipient patients was prepared with oral E(2) and P.

MAIN OUTCOME MEASURE(S)

Pregnancy and implantation rates in a donor program.

RESULT(S)

A significant increase in MII oocyte (80% vs. 71%), fertilization rates (83% vs. 71%), G1 embryos (17% vs. 3%), and implantation rates (35% vs. 15%), were found in recipients whose embryos originated from donors receiving GnRH-a + recombinant LH as compared to donors receiving GnRH-a alone. Estradiol levels, pregnancy/transfer and clinical pregnancies were lower (not significant) in donors treated with the GnRH-a alone vs. those receiving the recombinant LH-supplemented GnRH-a.

CONCLUSION(S)

The LH supplementation improved the possibilities of gestation for recipients whose embryos originated from GnRH-a-treated donors.

Minimal stimulation using recombinant follicle-stimulating hormone and a gonadotropin-releasing hormone antagonist in women of advanced age

OBJECTIVE

To determine whether minimal stimulation with short-term application of low-dose recombinant follicle-stimulating hormone (FSH) together with a gonadotropin-releasing hormone (GnRH) antagonist represents a cost-effective treatment regimen for patients with elevated FSH levels, aged 40 and above.

DESIGN

Retrospective cohort study.

SETTING

Academically affiliated private in vitro fertilization (IVF) program.

PATIENT(S)

Eighty-five IVF cycles using minimal ovarian stimulation and 85 cycles with a standard long-stimulation protocol, conducted between January 2000 and January 2002, in women aged 40 and above who had slightly increased FSH levels.

INTERVENTION(S)

Patients on the long protocol underwent standard cycle monitoring and stimulation. In contrast, women with minimal stimulation had transvaginal sonography initiated on day 8 of the menstrual cycle and at a follicle size of 13 mm. We administered 0.25 mg of GnRH antagonist and 75 IU recombinant FSH daily until ovulation induction.

MAIN OUTCOME MEASURE(S)

Numbers of oocytes, and rates of cancellation and pregnancy.

RESULT(S)

Minimal stimulation cycles resulted in a clinical pregnancy rate of 8.2% per started cycle and 10% per embryo transfer (ET), whereas the control group yielded a clinical pregnancy rate of 10.6% per started cycle and of 10.7% per ET (not statistically significant).

CONCLUSION(S)

In women aged 40 and above with abnormal FSH levels, minimal stimulation protocol achieves similar pregnancy rates to a standard protocol, and thus represents a cost-effective alternative.

Gonadotropin releasing hormone analogue (GnRHa) alters the expression and activation of Smad in human endometrial epithelial and stromal cells

Gonadotropin releasing hormone analogues (GnRHa) are often used to regress endometriosis implants and prevent premature luteinizing hormone surges in women undergoing controlled ovarian stimulation. In addition to GnRH central action, the expression of GnRH and receptors in the endometrium implies an autocrine/paracrine role for GnRH and an additional site of action for GnRHa. To further examine the direct action of GnRH (Leuprolide acetate) in the endometrium, we determined the effect of GnRH on endometrial stromal (ESC) and endometrial surface epithelial (HES) cells expression and activation of Smads (Smad3, -4 and -7), intracellular signals activated by transforming growth factor beta (TGF-beta), a key cytokine expressed in the endometrium. The results show that GnRH (0.1 microM) increased the expression of inhibitory Smad7 mRNA in HES with a limited effect on ESC, while moderately increasing the common Smad4 and Smad7 protein levels in these cells (P < 0.05). GnRH in a dose--(0.01 to 10 microM) and time--(5 to 30 min) dependent manner decreased the rate of Smad3 activation (phospho-Smad3, pSmad3), and altered Smad3 cellular distribution in both cell types. Pretreatment with Antide (GnRH antagonist) resulted in further suppression of Smad3 induced by GnRH, with Antide inhibition of pSmad3 in ESC. Furthermore, co-treatment of the cells with GnRH + TGF-beta, or pretreatment with TGF-beta type II receptor antisense to block TGF-beta autocrine/paracrine action, in part inhibited TGF-beta activated Smad3. In conclusion, the results indicate that GnRH acts directly on the endometrial cells altering the expression and activation of Smads, a mechanism that could lead to interruption of TGF-beta receptor signaling mediated through this pathway in the endometrium.

Exposure to high levels of luteinizing hormone and estradiol in the early follicular phase of gonadotropin-releasing hormone antagonist cycles is associated with a reduced chance of pregnancy

OBJECTIVE

To compare ongoing implantation rates under two different GnRH antagonist protocols.

DESIGN

Randomized controlled trial.

SETTING

Tertiary referral center.

PATIENT(S)

One hundred eleven women undergoing ovarian stimulation for in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).

INTERVENTION(S)

Ovarian stimulation with 150 IU recombinant-FSH (rec-FSH) starting on day 2 of the cycle and GnRH antagonist starting either on day 6 of stimulation (fixed group) or when a follicle of > or = 15 mm was present after at least 5 days of stimulation (flexible group). In the flexible group, the rec-FSH dose was increased to 250 IU when the antagonist was initiated.

MAIN OUTCOME MEASURE(S)

Ongoing implantation and pregnancy rate.

RESULT(S)

In patients with no follicle of > or = 15 mm present on day 6 of stimulation, a significantly lower ongoing implantation rate was observed if the flexible scheme was applied as compared with the fixed scheme of administration (8.8% vs. 23.9%, respectively). Exposure of the genital tract to LH or E2 from initiation of stimulation to antagonist administration was able to distinguish between pregnant and nonpregnant patients in the population studied.

CONCLUSION(S)

High exposure of the genital tract to LH and E2 in the early follicular phase is associated with a reduced chance of pregnancy in cycles stimulated with recombinant FSH and GnRH antagonist for IVF/ICSI.

Gonadotropin-releasing hormone and reproductive medicine

The hypothalamic gonadotropin-releasing hormone (GnRH) is a key regulator of the reproductive system, mainly through its effects on pituitary luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release. Gonadotropin-releasing hormone analogues are modifications of the natural decapeptide, being either agonists (GnRHa) or antagonists. GnRHa may imitate the native hormone and induce an endogenous LH surge; however, sustained treatment with GnRHa results in complete refractoriness of LH and FSH production. This aspect of GnRHa action is the main application of the GnRHa in reproduction today. The hypogonadotropic hypogonadal state that results from the sustained treatment is the basis for additional applications of the GnRHa. The agonists appear to be effective, to some extent, for the treatment of endometriosis and were proved to be beneficial prior to surgery for fibroma uteri. GnRHa is used in assisted reproduction for both induction of an endogenous LH surge and for induction of ovulation, and its capacity to cause refractoriness of the pituitary may be used to avoid a premature LH surge. It is suggested that the GnRHa have a direct effect on ovarian steroidogenesis, which is independent of its action on the pituitary. This unwanted effect and other possible drawbacks of the agonists are thought to be eliminated with the use of the antagonists. The mechanism of action of these antagonists is through competitive blocking of the GnRH receptor, which results in a rapid but reversible suppression of gonadotropin secretion. As for GnRHa, GnRH antagonists have been proven effective to prevent the LH surge and to reduce the incidence of severe ovarian hyperstimulation syndrome in controlled ovarian stimulation cycles.

The place of gonadotrophin-releasing hormone antagonists in reproductive medicine

Gonadotrophin-releasing hormone (GnRH) antagonists have recently been introduced into clinical practice. They appear to offer a promising alternative to the long-established GnRH agonist regimens for prevention of a premature LH surge during ovarian stimulation for assisted reproductive techniques. Clinical outcomes achieved with antagonists are comparable with those of a long GnRH agonist protocol, while treatment times and gonadotrophin requirements are reduced and safety is improved. In particular, the antagonists appear to be associated with a lower risk of ovarian hyperstimulation syndrome (OHSS) than do agonists. Patient surveys suggest a preference for antagonist over agonist treatment cycles. These benefits suggest that GnRH antagonists have the potential to replace agonists as the treatment of choice in ovarian stimulation for assisted reproductive techniques. Two agents, cetrorelix and ganirelix, are currently in clinical use. Cetrorelix is available in single- and multiple-dose formulations, offering increased flexibility compared with ganirelix.

Comparable effectiveness using flexible single-dose GnRH antagonist (cetrorelix) and single-dose long GnRH agonist (goserelin) protocol for IVF cycles – a prospective, randomized study

This prospective randomized study compared the effectiveness of a flexible single-dose gonadotrophin-releasing hormone (GnRH) antagonist (cetrorelix) and a single-dose long GnRH agonist (goserelin) protocol for ovarian stimulation in IVF/intracytoplasmic sperm injection (ICSI) cycles. All patients from the waiting list were successively included in the study, pre-programmed with an oral contraceptive, and randomized into goserelin and cetrorelix groups. Depending on the date on which their menstrual period started, patients took oral contraceptives for one or two cycles. Ultimately, 236 patients in the first group received a single dose of depot preparation of goserelin and 224 patients received a single 3 mg dose of cetrorelix in the late follicular phase, when the mean follicle diameter exceeded 12 mm. The mean number of ampoules of FSH and the duration of stimulation was statistically significantly lower in the cetrorelix group than in the goserelin group (25.9 versus 34.5, and 9.6 versus 12.2 days, P < 0.01). The mean number of oocytes retrieved was similar (6.7 +/- 4.5 versus 7.2 +/- 4.6, NS). Similar results were observed in fertilization rates, blastulation rates and blastocyst transfer rates in both groups. Clinical pregnancy and delivery rates per cycle were higher in the goserelin group (34.3 and 30.1%) than in the cetrorelix group (31.9 and 28.3%), but the differences were not statistically significant. The flexible single-dose GnRH antagonist protocol is an advantageous alternative to the long GnRH agonist protocol, with similar efficacy, shorter duration, a significant reduction in the number of FSH ampoules used and without the menopause-like effects of the GnRH antagonist.

Effect of ovarian stimulation with recombinant follicle-stimulating hormone, gonadotropin releasing hormone antagonists, and human chorionic gonadotropin on endometrial maturation on the day of oocyte pick-up

OBJECTIVE

To assess the effect of ovarian stimulation with recombinant FSH, GnRH antagonists, and hCG on endometrial maturation on the day of oocyte pick-up.

DESIGN

Prospective study.

SETTING

Tertiary referral center.

PATIENT(S)

Fifty-five women undergoing controlled ovarian hyperstimulation for IVF/intracytoplasmic sperm injection (ICSI).

INTERVENTION(S)

[1] Ovarian stimulation with recombinant FSH, starting on day 2 of the cycle and GnRH antagonist, starting after a median of 6 days of recombinant FSH stimulation (range, 5-12 days); [2] hCG administration for ovulation induction; and [3] aspirational biopsy of endometrium at oocyte pick-up.

MAIN OUTCOME MEASURE(S)

Endometrial histology at oocyte pick-up by Noyes criteria.

RESULT(S)

Advancement of endometrial maturation (2.5 +/- 0.1 days) as compared to the expected chronological date was observed in all antagonist cycles at oocyte retrieval. Endometrial advancement at oocyte pick-up increased in line with values of LH at initiation of stimulation and the duration of recombinant FSH treatment before the antagonist was started.

CONCLUSION(S)

The higher the values of LH at initiation of stimulation and the longer the duration of recombinant FSH treatment before the antagonist is started, the more advanced the endometrial maturation at oocyte pick-up.

Comparison of cryopreservation outcome with gonadotropin-releasing hormone agonists or antagonists in the collecting cycle

OBJECTIVE

To compare the pregnancy rates of frozen-thawed 2-pronucleate (2PN) oocytes obtained either in a long protocol or in an antagonist protocol and ovarian stimulation with either human menopausal gonadotropin (hMG) or recombinant follicular stimulating hormone (recFSH).

DESIGN

Retrospective data analysis.

SETTING

Academic infertility center.

PATIENT(S)

Three hundred forty-two infertile couples who underwent a transfer of cryopreserved 2PN oocytes.

INTERVENTION(S)

hMG (n = 194) or recFSH (n = 92) in a long protocol or hMG (n = 16) or recFSH (n = 40) stimulation under pituitary suppression with the GnRH antagonist Cetrotide was used. The 2PN oocytes were transferred after endometrial preparation using E(2) valerate and vaginal progesterone (Crinone 8% vaginal gel).

MAIN OUTCOME MEASURE(S)

Implantation, pregnancy, and abortion rates.

RESULT(S)

Implantation rates in the freeze-thaw cycles were 5.6% (hMG) and 3.8% (recFSH) with 2PN oocytes from the long protocol and 7% from the antagonist cycles, irrespective of whether hMG or recFSH was used. Pregnancy rates were similar independent of whether they resulted from the long-protocol cycles with hMG (15.4%) and recFSH (13.1%) or from the antagonist protocol cycles with hMG (25.0%) and recFSH (17.5%).

CONCLUSION(S)

The potential to implant is independent of the gonadotropin-releasing hormone analogue and gonadotropin chosen for the collection cycle when previously cryopreserved 2PN oocytes were replaced after thawing in the cleavage stage.