High doses of gonadotrophin-releasing hormone antagonist in in-vitro fertilization cycles do not adversely affect the outcome of subsequent freeze-thaw cycles

Effects of controlled ovarian stimulation regimens on top-quality blastocyst development and perinatal outcomes with the freeze-all strategy: A retrospective comparative study

OBJECTIVE

This study aimed to determine the effect of ovarian stimulation regimens on the top-quality blastocyst development rate and perinatal outcomes with the freeze-all strategy.

METHODS

A retrospective comparative cohort analysis of 149 in vitro fertilization (IVF) cycles using the freeze-all strategy was conducted. The IVF cycles were stimulated with either a gonadotropin-releasing hormone antagonist or clomiphene citrate along with gonadotropin based on the patient's serum anti-Müllerian hormone level. Oocyte retrieval, fertilization, and embryo culture were performed following standard procedures. All good-quality blastocysts were cryopreserved and used for frozen-thawed embryo transfer (FET) in subsequent cycles. The fertilization, blastulation, and top-quality blastocyst development rates were calculated. The perinatal outcomes of FET cycles, gestational period, and birth weight were assessed.

RESULTS

The main outcome of this study was the top-quality blastocyst development rate, and the secondary outcomes were perinatal parameters (e.g., gestational period and birth weight) between the stimulation regimens. Despite the higher number of usable-quality embryos in the antagonist group, the blastocyst development rate remained comparable (p=0.105). Similarly, perinatal outcomes were comparable in subsequent FET cycles (p=0.538).

CONCLUSION

These findings suggest that the choice between antagonist and clomiphene citrate with gonadotropin as stimulation in controlled ovarian stimulation regimens may not affect the top-quality blastocyst development rate. The IVF outcomes (e.g., clinical pregnancy, miscarriage, and live birth rates) remained unaffected in subsequent FET cycles. Unlike fresh embryo transfer, the birth weight and gestational length were not associated with prior controlled ovarian stimulation regimens when the freeze-all strategy was used.

Can we alter pregnancy outcome by adjusting progesterone treatment at mid-luteal phase: a randomized controlled trial

Our study aimed to determine whether mid-luteal serum P concentrations can serve as a predictive factor for in vitro fertilization (IVF) outcomes and whether increasing P dosage for patients with low levels at mid-luteal phase may improve pregnancy rates. It was a prospective, randomized controlled study. A total of 146 patients undergoing IVF treatment were prospectively enrolled and received routine luteal phase support (LPS) regimen of Endometrin® (progesterone) 200 mg/day. Serum P levels were measured 7 days after embryo transfer (ET). Considering a cutoff level of 15 ng/ml on this day, patients with higher levels continued the same dosage until pregnancy test (control group). Patients with lower levels were randomly allocated to continue Endometrin® 200 mg/day (Group A) or to increase Endometrin® dosage to 300 mg/day (Group B). The Main Outcome Measures were pregnancy rates. Both biochemical and clinical pregnancy and live birth rates were comparable between all groups regardless of P level on day 7 of luteal phase and regardless of dose adjustment. ROC analysis determined that mid-luteal P levels of 17 ng/ml can be a better predictor of cycle outcome. In conclusion raising the P dose at mid-luteal phase to 300 mg daily did not improve cycle outcomes.

Addition of gonadotropin releasing hormone agonist for luteal phase support in in-vitro fertilization: an analysis of 2739 cycles

OBJECTIVE

Luteal phase is defective in in vitro fertilization (IVF) cycles, and many regimens were tried for the very best luteal phase support (LPS). Gonadotropin releasing hormone (GnRH) agonist use, which was administered as an adjunct to the luteal phase support in IVF cycles, was suggested to improve pregnancy outcome measures in certain randomized studies. We analyzed the effects of addition of GnRH agonist to standard progesterone luteal support on pregnancy outcome measures, particularly the live birth rates.

MATERIAL AND METHODS

This is a retrospective cohort study, including 2739 IVF cycles. Long GnRH agonist and antagonist stimulation IVF cycles with cleavage-stage embryo transfer were included. Cycles were divided into two groups: Group A included cycles with single-dose GnRH agonist plus progesterone LPS and Group B included progesterone only LPS. Live birth rates were the primary outcome measures of the analysis. Miscarriage rates and multiple pregnancy rates were the secondary outcome measures.

RESULTS

Live birth rates were not statistically different in GnRH agonist plus progesterone (Group A) and progesterone only (Group B) groups in both the long agonist and antagonist stimulation arms (40.8%/41.2% and 32.8%/34.4%, p<0.05 respectively). Moreover, pregnancy rates, implantation rates, and miscarriage rates were found to be similar between groups. Multiple pregnancy rates in antagonist cycles were significantly higher in Group A than those in Group B (12.0% and 6.9%, respectively).

CONCLUSION

A beneficial effect of a single dose of GnRH agonist administration as a luteal phase supporting agent is yet to be determined because of the wide heterogeneity of data present in literature. Well-designed randomized clinical studies are required to clarify any effect of luteal GnRH agonist addition on pregnancy outcome measures with different doses, timing, and administration routes of GnRH agonists.

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.

Outcome of cryopreserved pronuclear oocytes obtained after ovarian stimulation with either HMG or recFSH and the GnRH-antagonist cetrorelix

The present retrospective study evaluated the outcome of frozen-thaw cycles with oocytes obtained either during a multiple dose protocol of cetrorelix, or after the use of a gonadotrophin-releasing hormone (GnRH) agonist. A total of 101 subfertile couples were included. These couples had a total of 222 transfers of frozen-thawed pronuclear oocytes after IVF/intracytoplasmic sperm injection (ICSI) treatment. According to the stimulation protocol during various cycles, four groups were established: cetrorelix/recombinant FSH (recFSH) (69 cycles), cetrorelix/human menopausal gonadotrophin (HMG) (10 cycles), GnRH-agonist/recFSH (71 cycles) and GnRH-agonist/HMG (72 cycles). The transfer cycles were mildly stimulated with transdermal oestradiol. No statistically significant difference was seen among the four groups regarding post-thaw survival rate, cumulative embryo score, implantation rate and pregnancies. Frozen-thawed pronuclear oocytes obtained with the use of cetrorelix give satisfactory implantation and pregnancy rates, similar to those obtained with a GnRH-agonist. These results do not depend on the gonadotrophins (HMG or recFSH) used in the collecting cycle.

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.

Safety aspects of gonadotrophin-releasing hormone antagonists in ovarian stimulation procedures: ovarian hyperstimulation syndrome and health of children born

The safety of ovarian stimulation procedures or the procedure of assisted reproduction in general can be estimated by various parameters. Two of the most important are the health of children born after the procedure and the incidence of ovarian hyperstimulation syndrome (OHSS). The latter is important because it is the most severe, potentially life-threatening complication of any stimulation procedure. The use of gonadotrophin-releasing hormone (GnRH) antagonists in ovarian stimulation protocols has had no impact on the health of children born. This was proven in 227 children born after the use of cetrorelix and in 73 children born after the use of ganirelix. To analyse the incidence of OHSS and the impact of GnRH antagonists on clinical pregnancy rates compared with the long protocol, a meta-analysis was done. This showed a reduction of OHSS with the use of cetrorelix. Furthermore, when compared with the long protocol, clinical and ongoing pregnancy rates were not significantly reduced with the use of cetrorelix. Taken together, the use of GnRH antagonists are safe with regard to children's health. The incidence of OHSS does not increase with ganirelix, and a reduction can be expected with cetrorelix.

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.

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.

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.

The impact of ovarian stimulation for IVF on the developing embryo

The use of assisted reproductive technologies (ART) has been increasing over the past three decades, and, in developed countries, ART account for 1-3% of annual births. In an attempt to compensate for inefficiencies in IVF procedures, patients undergo ovarian stimulation using high doses of exogenous gonadotrophins to allow retrieval of multiple oocytes in a single cycle. Although ovarian stimulation has an important role in ART, it may also have detrimental effects on oogenesis, embryo quality, endometrial receptivity and perinatal outcomes. In this review, we consider the evidence for these effects and address possible underlying mechanisms. We conclude that such mechanisms are still poorly understood, and further knowledge is needed in order to increase the safety of ovarian stimulation and to reduce potential effects on embryo development and implantation, which will ultimately be translated into increased pregnancy rates and healthy offspring.

Effects of gonadotrophin releasing hormone analogues on human endometrial stromal cells and embryo invasion in vitro

BACKGROUND

Gonadotrophin releasing hormone (GnRH) analogues are widely used in IVF programmes as a method of suppressing the luteinizing hormone (LH) surge prior to ovarian stimulation, but their roles outside the pituitary remain relatively unknown. A 2002 Cochrane review (Al-Inany et al. Gonadotrophin-releasing hormone antagonists for assisted conception. Cochrane Database Syst Rev 2006;3:CD001750) described lower pregnancy rates in women administered with GnRH antagonist, compared with those using an agonist, as part of an IVF programme, despite the fact that GnRH antagonist is a more effective repressor of LH. This study aimed to analyse the in-vitro effects of GnRH analogues on the decidualizing endometrium, blastocyst invasion and GnRH receptor expression in fertile women.

METHODS

We analysed the in-vitro decidualization capacity of endometrial stromal cells, derived from fertile women during the implantation window, in the presence of GnRH analogues. The influence of GnRH analogues on GnRH receptor expression and blastocyst invasion was assessed by in-vitro assays of biomedical marker secretion, immunoblots and blastocyst attachment to the stromal extracellular matrix.

RESULTS

We demonstrate that, at the concentrations and time periods used, GnRH analogues did not significantly influence the extent of decidualization of endometrial stromal cells. In addition, no adverse effect of GnRH analogues was seen on human blastocyst invasion.

CONCLUSIONS

We suggest that GnRH analogues affect neither the capacity of the endometrium to support invasion nor the invasive potential of the blastocyst in the early stages of implantation.

Cessation of gonadotropin-releasing hormone antagonist on triggering day: an alternative method for flexible multiple-dose protocol

This study was performed to analyze retrospectively outcomes of stimulated in vitro fertilization (IVF) cycles where the gonadotropin-releasing hormone (GnRH) antagonist was omitted on ovulation triggering day. A total of 92 consecutive IVF cycles were included in 65 women who are undergoing ovarian stimulation with recombinant FSH. A GnRH antagonist, cetrorelix 0.25 mg/day, was started when leading follicle reached 14 mm in diameter until the day of hCG administration (Group A, 66 cycles) or until the day before hCG administration (Group B, 26 cycles). The duration of ovarian stimulation, total dose of gonadotropins, serum estradiol levels on hCG administration day, and the number of oocytes retrieved were not significantly different between the two groups. The total dose of GnRH antagonist was significantly lower in Group B compared to Group A (2.7+/-0.8 vs. 3.2+/-0.9 ampoules). There was no premature luteinization in the subjects. The proportion of mature oocytes (71.4% vs. 61.7%) and fertilization rate of mature (86.3+/-19.7% vs. 71.8+/-31.7%) was significantly higher in Group B. There were no significant differences in embryo quality and clinical pregnancy rates. Our results suggest that cessation of the GnRH antagonist on the day of hCG administration during a flexible multiple-dose protocol could reduce the total dose of GnRH antagonist without compromising IVF results.

GnRH analogues: applications in assisted reproductive techniques

The ability to prevent an endogenous LH surge revolutionised the efficacy of assisted reproductive techniques (ART) such that GnRH agonists were rapidly adopted in the 1980s. Prior to this, premature luteinisation occurred in up to 25% of superovulated cycles leading to cycle cancellation and severely compromised outcomes. Analogues have been applied in a variety of drug protocols (long, short flare) but there has been little research to moderate the degree of pituitary suppression. There has also been ongoing and unresolved debate about the role of LH in supporting follicular development. By 2001, the first GnRH antagonists were registered for use in ART. Their ability to cause immediate suppression of gonadotrophin (particularly LH) secretion means that they can be given after exogenous stimulation has begun and thereby dramatically shorten the total duration of a treatment cycle. After initial enthusiasm and then scepticism that pregnancy rates may not be as high as the established agonist regimens, these preparations are now being increasingly adopted with at least comparable outcomes in large trials. They are certainly favoured by patients for their reduced side-effect profile and particularly for the shortening of the total cycle length. This shift in practice is occurring alongside gathering momentum in favour of milder stimulation protocols and a new perception of what constitutes successful treatment. The focus is moving away from surrogate outcomes such as oocyte numbers and conception rates towards long-term outcomes for women and their offspring, namely the achievement of a live singleton birth per treatment started.

The effects of GnRH antagonist on the endometrium of normally menstruating women

PURPOSE

To study the effects of GnRH antagonist (ganirelix-Orgalutran) on the endometrium of regularly menstruating women.

MATERIALS AND METHODS

Prospective, self-controlled study. The thirty-five volunteers were studied for two cycles: one as a control and the other, GnRH antagonist-treated cycles in which ganirelix 0.25 mg/d was given daily for 3 days, starting when the largest follicle reached 15 mm. In both cycles, serum estradiol, LH and endometrial thickness were measured when the largest follicle was > or =18 mm. Endometrial biopsy was performed on day 6 after ovulation for histological dating and morphometric study.

RESULTS

No statistical differences between histological dating and the endometrial thickness in the control and GnRH antagonist-treated cycles. All morphometric parameters were also not different. Serum estradiol and LH levels were significantly lower in GnRH antagonist-treated cycles.

CONCLUSION

GnRH antagonist has no effect on the endometrium of regularly menstruating women as assessed by either histological dating or morphometric analysis.

Cryopreserved blastocyst transfer: impact of gonadotropin-releasing hormone agonist versus antagonist in the previous oocyte retrieval cycles

OBJECTIVE

To assess any detrimental effect of gonadotropin-releasing hormone (GnRH) antagonists on oocyte quality and embryo development by comparing the outcome of cryopreserved-thawed blastocyst transfers for cycles using a GnRH agonist or GnRH antagonist protocol for the controlled ovarian stimulation in the oocyte retrieval cycle.

DESIGN

Retrospective comparative study.

SETTING

Private IVF center.

PATIENT(S)

Seventy-seven women who underwent cryopreserved-thawed blastocyst transfer.

INTERVENTION(S)

The patients were divided into two groups based on whether they had been treated using a GnRH agonist long protocol (n = 44) or a GnRH antagonist multiple-dose protocol (n = 33) during the previous oocyte retrieval cycle. Cryopreserved-thawed blastocysts were transferred after endometrial preparation without pituitary suppression using a GnRH agonist.

MAIN OUTCOME MEASURE(S)

Implantation and clinical pregnancy rates.

RESULT(S)

The postthaw survival rate and numbers of good quality blastocysts transferred were similar for the GnRH agonist and GnRH antagonist groups. Implantation and pregnancy rates for cryopreserved-thawed blastocyst transfer for the GnRH agonist group versus the GnRH antagonist group were 21.0% (25 of 119) versus 29.0% (27 of 93) and 38.6% (17 of 44) versus 51.5% (17 of 33), respectively, which was not statistically significantly different.

CONCLUSION(S)

No difference was found in terms of implantation and pregnancy rates when a GnRH agonist or GnRH antagonist was used in the previous oocyte retrieval cycle. Our results suggest that GnRH antagonists do not have a detrimental effect on oocyte quality or embryo development.

Clinical outcomes using a flexible regimen of GnRH-antagonists and a 'step-up' of additional gonadotropins in donor oocyte cycles

OBJECTIVE

To assess the impact of serum estradiol upon oocyte donor cycle stimulation characteristics and clinical outcomes using flexible GnRH-antagonist (GnRH-ant) with additional FSH supplementation.

RESEARCH DESIGN AND METHODS

A retrospective chart review of 99 oocyte donor cycles using ovarian hyperstimulation with recombinant FSH (rFSH) and GnRH-ant was analyzed. Following discontinuation of oral contraceptives, controlled ovarian hyperstimulation was begun using rFSH (150-300 IU daily). GnRH-ant (ganirelix, Organon) and an additional 75 IU of FSH/day were begun when lead follicles were 13-14 mm in greatest diameter. Cycles were analyzed based on serum estradiol response following administration of GnRH-ant (Group 1: progressive rise and Group 2: no rise or a decline). Primary endpoints were cycle stimulation characteristics based on serum estradiol following GnRH-ant, clinical pregnancy and implantation rates.

RESULTS

A decline in serum estradiol was seen after GnRH-ant administration in 45% of cycles. Clinical pregnancy rates per transfer (70 vs. 72%) and implantation rates (43 vs. 56%) were similar for each group.

CONCLUSION

Flexible regimens of GnRH-ant even with additional rFSH in a 'step-up' fashion frequently result in a decline in serum estradiol during ovulation induction. While our study is non-randomized, it does not appear to result in any adverse affect in clinical outcomes in donor oocyte cycles.

High-dose recombinant LH add-back strategy using high-dose GnRH antagonist is an innovative protocol compared with standard GnRH antagonist

High daily doses of gonadotrophin-releasing hormone (GnRH) antagonists during the follicular phase of ovarian stimulation were associated with low implantation rates. To test if this occurred because of profound pituitary suppression, the pituitary response was suppressed with a high-dose GnRH antagonist and recombinant LH (rLH) was added back to correct the implantation rate. An open-label, randomized, controlled, prospective clinical study in 60 patients undergoing IVF was performed. GnRH antagonist was initiated on day 6 of stimulation (2 mg/day) together with 375 IU rLH, and maintained until the day of HCG administration. Controls received 0.25 mg/day GnRH antagonist. Fluctuating LH concentrations were present on days 3 and 6 in both groups. This strong fluctuation continued on day 8 and on the day of HCG administration in the control (low-dose) group, where 30% of patients had LH concentrations <1 IU/l on the HCG day. The study (high-dose) group showed stable LH concentrations on day 8 and on the HCG day, with no LH surges. No clinical differences were found between groups. The LH add-back strategy (375 IU/day) rescued the adverse effects that high doses of GnRH imposed on implantation. These results suggest that rLH should be considered during ovarian stimulation with GnRH antagonist.

Similar outcome for cryopreserved embryo transfer following GnRH-antagonist/GnRH-agonist, GnRH-antagonist/HCG or long protocol ovarian stimulation

The pregnancy rates after triggering of final oocyte maturation with gonadotrophin-releasing hormone (GnRH) agonist in GnRH-antagonist ovarian stimulation protocols are lower than those following triggering with human chorionic gonadotrophin (HCG). Furthermore, lower pregnancy rates following GnRH-antagonist protocols compared with long GnRH-agonist protocols have been reported. The differences might be due to an impact on oocyte number and quality or on the endometrium. If any stimulation protocol had a negative impact on oocyte quality, then further evidence of this effect would be observed following frozen-thawed embryo transfer originating from that stimulation cycle. The outcome of frozen-thawed embryo transfer was retrospectively analysed using the long protocol with triptorelin depot 3.75 mg (n = 215) or 0.1 mg/day (n = 83), or GnRH-antagonist protocol with either HCG (n = 69) or GnRH-agonist (n = 25) for final oocyte maturation. The outcomes measured were implantation rate, clinical pregnancy rate, ongoing pregnancy rate and embryo survival rate. All outcomes were similar in the four groups. It is concluded that the potential for frozen-thawed embryos to implant and develop following transfer is independent of the GnRH-analogue and the final oocyte maturation protocol used in the collection cycle. Lower IVF embryo transfer success using GnRH-antagonist/GnRH-agonist protocol does not appear to be related to an adverse effect on oocyte quality.

Gonadotropin-releasing hormone antagonist in in vitro fertilization superovulation

The use of gonadotropin-releasing hormone (GnRH) antagonists in in vitro fertilization superovulation remains controversial. The GnRH agonist 'long protocol' has been seen as the gold standard for many years. Comparisons and meta-analyses of the efficacy of GnRH antagonists and agonists have been largely inconclusive, with the dataset being contaminated with outdated reports of poorer efficacy with GnRH antagonists, which have stemmed from studies of their use as a second-line drug in older women and women who were poor responders. This work cannot reflect the actual clinical effectiveness of GnRH antagonist and must be interpreted with care. The major advantages of GnRH antagonists use in superovulation include a gentler and more patient-friendly stimulation cycle with less hypoestrogenic side effects, with the potential to lower the risk of ovarian hyperstimulation and enhanced embryo growth. Our current clinical experience with GnRH antagonists in in vitro fertilization is limited, although there are a growing number of in vitro fertilization centers embracing this new technology. There is a clear need for a modern, suitably powered clinical trial to demonstrate the place of GnRH antagonist-based superovulation protocols and in subgroups of patients, such as polycystic ovary syndrome or poor responders.

Among patients treated for IVF with gonadotrophins and GnRH analogues, is the probability of live birth dependent on the type of analogue used? A systematic review and meta-analysis

This systematic review and meta-analysis aimed to answer the following clinical question: among patients treated for IVF with gonadotrophins and GnRH analogues, is the probability of live birth per randomized patient dependent on the type of analogue used? Eligible studies were randomized controlled trials (RCTs), published as a full manuscript in a peer-reviewed journal, that contained sufficient information to allow ascertainment of whether randomization was true and whether equality was present between the groups compared. A literature search identified 22 RCTs comparing GnRH antagonists and GnRH agonists that involved 3176 subjects. Where live birth was not reported in a study that fulfilled the inclusion criteria, an effort was made to contact the corresponding authors to retrieve the missing information. If this was not possible, the reported outcome measure, clinical pregnancy or ongoing pregnancy was converted to live birth in 12 studies using published data (Arce et al., 2005). No significant difference was present in the probability of live birth between the two GnRH analogues [odds ratio (OR), 0.86; 95% confidence intervals (CI), 0.72 to 1.02]. This result remains stable in subgroup analysis that ordered the studies by type of population studied, gonadotrophin type used for stimulation, type of agonist protocol used, type of agonist used, type of antagonist protocol used, type of antagonist used, presence of allocation concealment, presence of co-intervention and the way the information on live birth was retrieved. In conclusion, the probability of live birth after ovarian stimulation for IVF does not depend on the type of analogue used for pituitary suppression.

Is a lower dose of cetrorelix acetate effective for prevention of LH surge during controlled ovarian hyperstimulation?

PURPOSE

This study was performed to evaluate whether a lower dose (0.2 mg) of cetrorelix would prevent premature LH surge in patients undergoing controlled ovarian hyperstimulation.

METHODS

Controlled ovarian hyperstimulation was carried out in 45 patients, starting on menstrual cycle day 3 with recombinant FSH (r-FSH), and a cetrorelix of 0.2 mg was administered from day 5 evening of ovarian stimulation until the day before hCG injection.

RESULTS

There was a statistically significant decrease in serum LH level one day after the first cetrorelix injection and on the day of hCG administration. Serum LH concentrations were maintained constantly low during the follicular phase with no premature LH surge occurring in any of the patients. Clinical pregnancy was achieved for 18 women (40%), with one of these experiencing intrauterine fetal death before 12 week' gestation.

CONCLUSION

This study demonstrates that a daily dose of cetrorelix 0.2 mg is able to prevent premature LH surge.

Outcome of frozen-thawed blastocysts derived from gonadotropin releasing hormone agonist or antagonist cycles

PURPOSE

The aim of this retrospective study was to compare the outcome of frozen-thawed blastocysts derived from the cycles using controlled ovarian stimulation with GnRH agonists vs. GnRH antagonists.

METHODS

Survival, pregnancy and cumulative live birth rates in 231 freeze-thaw cycles derived from the GnRH agonist cycles (GnRH agonist group), and in 175 freeze-thaw cycles derived from the GnRH antagonist cycles (GnRH antagonist group) were compared.

RESULTS

In the GnRH agonist group significantly higher proportion of blastocysts survived the thawing procedure than in the GnRH antagonist group (86.1% versus 78.5%; p < 0.01). The differences in cumulative live birth rates did not differ significantly between the groups: in the GnRH agonist group the cumulative live birth rate was 16.5%, and in the GnRH antagonist group it was 14.2%.

CONCLUSIONS

Frozen-thawed blastocysts derived from the GnRH agonist cycles have better survival rates and similar cumulative live birth rates than those derived from the GnRH antagonist cycles.

Cetrorelix in women with poor ovarian response in previous assisted reproduction cycles

Our aim was to compare a gonadotrophin-releasing hormone (GnRH) antagonist protocol with an analogue protocol using high dose gonadotrophins (rFSH) in women with poor ovarian response in order to optimise the management while undergoing assisted reproduction treatment. We recruited 31 consecutive patients over 5 months. The eligibility criteria for the study were: one or more previous cancelled cycle due to <or=3 follicles on day of hCG, or a total of >or=4,500 IU of rFSH. For the antagonist cycle regimen, we used daily 300 IU of rFSH from day 2 on the menses, and then from day 5 daily 0.25 mg of Cetrorelix until the day of human chorionic gonadotrophin (hCG) administration. We demonstrated that the use of an antagonist cycle was associated with a reduction in cancellation rates from 48% (agonist) to 10% (antagonist) (p < 0.039) allowing women to undergoing oocyte retrieval and embryo transfer with a non-significant improvement in the pregnancy rates.

The science behind 25 years of ovarian stimulation for in vitro fertilization

To allow selection of embryos for transfer after in vitro fertilization, ovarian stimulation is usually carried out with exogenous gonadotropins. To compensate for changes induced by stimulation, GnRH analog cotreatment, oral contraceptive pretreatment, late follicular phase human chorionic gonadotropin, and luteal phase progesterone supplementation are usually added. These approaches render ovarian stimulation complex and costly. The stimulation of multiple follicular development disrupts the physiology of follicular development, with consequences for the oocyte, embryo, and endometrium. In recent years, recombinant gonadotropin preparations have become available, and novel stimulation protocols with less detrimental effects have been developed. In this article, the scientific background to current approaches to ovarian stimulation for in vitro fertilization is reviewed. After a brief discussion of the relevant aspect of ovarian physiology, the development, application, and consequences of ovarian stimulation strategies are reviewed in detail.

Oocyte maturity and preimplantation development in relation to follicle diameter in gonadotropin-releasing hormone agonist or antagonist treatments

OBJECTIVE

To analyze the distribution of oocytes nuclear maturational stages and intracytoplasmic sperm injection (ICSI) outcome in relation to follicular size, after controlled ovarian hyperstimulation (COH), using gonadotropin-releasing hormone (GnRH) antagonist or agonist protocols.

DESIGN

Prospective comparative study.

SETTING

Fertility unit in an academic hospital.

PATIENT(S)

Normo-ovulatory patients with unexplained, male and/or tubal factor infertility undergoing ICSI treatment.

INTERVENTION(S)

Oocytes were retrieved from small (7-12 mm) and large follicles (>12 mm).

MAIN OUTCOME MEASURE(S)

Oocyte nuclear maturation stage, fertilization and pre-implantation embryonic development of the mature ova evaluated.

RESULT(S)

Distribution of oocyte maturation stages from small follicles did not differ between the two COH protocols. From large follicles, a statistically significantly higher percentage of immature oocytes was retrieved after antagonist compared with agonist treatment (16 vs 11%, respectively). No statistically significant differences existed regarding ICSI outcome of mature ova within the same follicle diameter range between COH protocols. Inseminated ova from small follicles presented a significantly higher number of embryos with delayed development on day 3 after ICSI.

CONCLUSION(S)

A greater heterogeneity of maturity was found in the population of oocyte stages that were present after the antagonist protocol. Matured oocytes retrieved from small follicles generated embryos of lower developmental potential than oocytes derived from larger follicles.

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.

Recombinant LH in ovarian stimulation

The advent of recombinant gonadotrophins brought significant changes in fertility therapy. Treatment options with recombinant gonadotrophins add more to knowledge on folliculogenesis and ovarian steroidogenesis. Over a decade, recombinant LH (rLH) has been used for clinical trials, and the amount of peripheral LH that is necessary for optimal follicular growth, oocyte maturation, subsequent embryo development and assisted reproduction outcome during ovulation induction can now be better evaluated. This review evaluates the effect of rLH supplementation on ovarian stimulation and assisted reproduction outcome. The studies conducted with rLH supplementation in ovarian stimulation in different groups of patients and in cases of controlled ovarian stimulation are clearly discussed in this review.

Are endogenous LH levels during ovarian stimulation for IVF using GnRH analogues associated with the probability of ongoing pregnancy? A systematic review

The aim of this systematic review was to evaluate, among women with normal ovulation or World Health Organization (WHO) II oligoanovulation who undergo ovarian stimulation for IVF using GnRH analogues, whether endogenous LH levels predict the likelihood of ongoing pregnancy beyond 12 weeks. A literature search identified six studies that answered the research question, among which two were prospective studies (one in GnRH agonist and one in GnRH antagonist cycles). None of the retrospective studies suggest that low endogenous LH levels are associated with a significantly decreased probability of ongoing pregnancy beyond 12 weeks in such patients. In the two prospective studies high endogenous LH levels during down-regulation were associated with a decreased probability of ongoing pregnancy beyond 12 weeks. Until further prospective studies modify the existing evidence summarized here, an adverse effect of low endogenous LH levels on the probability of ongoing pregnancy beyond 12 weeks is not a sensible rationale for LH supplementation during ovarian stimulation for IVF using GnRH analogues.

Similar endometrial development in oocyte donors treated with either high- or standard-dose GnRH antagonist compared to treatment with a GnRH agonist or in natural cycles

BACKGROUND

This descriptive study evaluates the impact on endometrial development of standard and high doses of a GnRH antagonist in stimulated cycles compared with GnRH agonist and natural cycles.

METHODS

Thirty-one oocyte donors were treated with a combination of rFSH and 0.25 mg/day ganirelix (standard dose), 2 mg/day ganirelix (high dose) or 0.6 mg/day buserelin (long protocol). Vaginal progesterone (200 mg/day) was administered in the luteal phase. Endometrial biopsies were performed 2 and 7 days after HCG administration. Additional biopsies were carried out in a subset of 12 subjects, 2 and 7 days following the LH peak of their previous natural cycle. Biopsies were evaluated histologically and by scanning electron microscopy. Gene expression profiles were also studied.

RESULTS

At HCG +2, all the parameters studied were similar in all the groups and comparable to those observed in the natural cycle. At HCG +7, endometrial dating, steroid receptors and the presence of pinopodes were comparable in both GnRH antagonist groups and in the natural cycle. In buserelin group, endometrial dating and pinopode expression suggested an arrested endometrial development. For window of implantation genes, expression patterns were closer to those in the natural cycle following standard- or high-dose ganirelix than after buserelin administration.

CONCLUSION

No relevant alteration was observed in the endometrial development in the early and mid-luteal phases in women undergoing controlled ovarian stimulation for oocyte donation following daily treatment with a standard- or high-dose GnRH antagonist. In addition, the endometrial development after GnRH antagonist mimics the natural endometrium more closely than after GnRH agonist.

Alternate day and daily administration of GnRH antagonist may prevent premature luteinization to a similar extent during FSH treatment

BACKGROUND

This randomized controlled trial was designed to evaluate whether a GnRH antagonist given every other day could prevent premature luteinization in women undergoing IVF/ICSI treatment.

METHODS

A total of 73 women receiving ovulation stimulation IVF cycles with recombinant FSH were allocated randomly on cycle day 7 to GnRH antagonist ganirelix in multiple doses (0.25 mg each), either daily (n = 37 women, group 1) or every other day (n = 36 women, group 2) until the day of HCG administration.

RESULTS

Serum FSH, LH, estradiol and progesterone values showed similar trends in the two groups. During FSH stimulation, 13 (35%) of the women in group 1 had premature LH rises (> or = 10 IU/l) of which eight (22%) were after the start of antagonist administration. In group 2 there were 14 (39%) LH rises during FSH stimulation of which 10 (28%) were after the start of antagonist administration. Luteinization (serum progesterone >2 ng/ml) occurred in only one woman in each group overall (3%). A significantly smaller total dose of the antagonist was used in group 2 than in group 1 (P < 0.001). The study did not have power to evaluate differences in total dose of FSH, number of oocytes recovered and clinical pregnancy rate, all of which appeared similar in the two groups.

CONCLUSIONS

Whether alternate day is as effective as daily administration of ganirelix in preventing premature luteinization should be addressed in a non-inferiority trial powered to evaluate live birth rate.

GnRH antagonists in IVF

The present review summarizes existing knowledge on the use of gonadotropin releasing hormone (GnRH) antagonists based on experience gathered after the completion of phase III comparative trials with GnRH agonists. Available data suggest that prolongation of the follicular phase significantly decreases the probability of pregnancy. Moreover, patients with elevated progesterone at initiation of stimulation have significantly fewer chances of achieving an ongoing pregnancy. Luteal support remains mandatory, while the replacement of human chorionic gonadotrophin by GnRH agonist does not appear to be feasible. Although not conclusive, existing data are not in favour of increasing the starting dose of gonadotrophins, of LH supplementation or of using a flexible antagonist protocol.

Use of antagonists in ovarian stimulation protocols

Gonadotrophin-releasing hormone (GnRH) antagonists have been introduced in IVF to prevent premature LH surge. They bind competitively to pituitary receptors and prevent endogenous GnRH from exerting any stimulus on pituitary cells, avoiding the initial 'flare-up' effect and decreasing gonadotrophin secretion within a few hours. Pituitary reserve and gonadotrophin synthesis are not affected; therefore, the recovery of pituitary function is rapid. Two different regimes have been described. The multiple-dose protocol involves the administration of 0.25 mg cetrorelix (or ganirelix) daily from day 6-7 of stimulation, or when the leading follicle is 14-15 mm, until human chorionic gonadotrophin (HCG) administration. The single-dose protocol involves the single administration of 3 mg cetrorelix on day 7-8 of stimulation. Both antagonists with either regimen seem to be equally effective in the prevention of the LH surge. Compared with a long luteal agonist protocol, the treatment is shorter and requires a smaller amount of gonadotrophins. Pregnancy rate seems to be lower, but a decrease in the incidence of severe ovarian hyperstimulation syndrome (OHSS) is reported by several studies. A promising aspect of antagonists may be the possibility of making treatment less aggressive. Finally, in antagonist cycles, ovulation triggering is possible by GnRH agonists, avoiding the deleterious effect of HCG and thus preventing OHSS.

Extrapituitary effects of GnRH antagonists in assisted reproduction: a review

GnRH antagonists are used to prevent premature LH surges in assisted reproduction. The pregnancy rates obtained in several studies have been similar to those obtained in the long protocol with gonadotrophin-releasing hormone (GnRH) agonists. However, lower oestrogen serum concentrations have been observed and fewer oocytes retrieved using GnRH antagonists. Thus, potential effects at extrapituitary GnRH receptors in the ovary and the endometrium have been claimed. The article reviews the currently available data from the literature as well as current investigations with respect to effects of cetrorelix on the ovary and the endometrium. No evidence was found to support the hypothesis of extrapituitary effects of GnRH antagonists such as cetrorelix at doses used in assisted reproduction.

Duration of gonadotropin-releasing hormone antagonist administration does not affect the outcome of subsequent frozen-thawed cycles

The duration of administration of GnRH antagonist in cycles stimulated with recombinant FSH for IVF/intracytoplasmic sperm injection does not affect the probability of blastocyst replacement and of achieving an ongoing pregnancy in subsequent frozen-thawed cycles.

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.

The role of LHRH agonists and antagonists

Administration of GnRH analogues (agonists as well as antagonists) produces suppression of the pituitary---gonadal axis, thus inhibiting the secretion of LH, FSH and sexual steroids. For this reason, analogs are indicated in all those clinical situations where suppression of gonadotrophins (precocious puberty, contraception) or of sexual steroids (endometriosis, prostate hyperplasia, cancer, uterine fibroids) is desired. For several years GnRH agonists have been used in combination with gonadotrophins for ovarian stimulation for assisted reproduction in order to control premature LH surges and to reduce cancellation rate with improvement of the pregnancy rate per cycle. This effect is obtained after 2 weeks of agonist administration. The immediate suppression of the pituitary achieved by GnRH antagonists without an initial stimulatory effect is the main advantage of these compounds over the agonists. The prevention of a premature LH surge by GnRH antagonists can be obtained by multiple dose or by a single administration. Both protocols offer the following advantages over the agonists: they require fewer ampoules of gonadotrophins, shorter duration of stimulation, there is a preserved pituitary response to GnRH, less risk of ovarian hyperstimulation syndrome and the luteal phase seems to be more preserved. The main disadvantages of the antagonists are that they are expensive and that pregnancy rate appears to be slightly lower than with the agonists. GnRH antagonists will probably replace agonists in ovarian stimulation treatment for assisted reproduction techniques.

Gonadotrophin-releasing hormone antagonists: will they replace the agonists?

Modern gonadotrophin-releasing hormone (GnRH) antagonists such as cetrorelix and ganirelix reliably prevent premature LH surges in controlled ovarian hyperstimulation for assisted reproductive technologies. Cetrorelix and ganirelix are safe and effective compounds. Because of their distinct pharmacological mode of action, it has been possible to achieve a significant reduction of treatment time. Fertilization and pregnancy rates are comparable to those obtained in agonist protocols for ovarian stimulation. No allergic or hyperergic reactions have been reported, and patient compliance is excellent. The fact that GnRH antagonists allow an immediate suppression of gonadotrophin concentrations while preserving pituitary responsiveness to endogenous GnRH provides enormous flexibility in treatment. GnRH antagonists have helped to overcome some major disadvantages of GnRH agonists, especially of the long protocol, which is currently the standard protocol for ovarian stimulation. The mistaken administration of antagonists during early pregnancy is not possible, since they are only administered during ovarian stimulation when a premature LH surge may be imminent. They are used in the spontaneous cycle or after pretreatment with oral contraceptives. Pregnancy can easily be ruled out by testing for human gonadotrophic hormone before onset of gonadotrophin stimulation on the second or third day of the cycle. Since flare-up effects are absent, there is no risk of cyst formation. Hormonal withdrawal symptoms are eliminated, since no period of pituitary suppression occurs, and therefore exogenous gonadotrophins are not required. Overall, the duration of the stimulation cycle is as short as a normal menstrual cycle. The procedure seems to be safer than the long protocol, since the most serious complication, the occurrence of severe cases of OHSS, is reduced. It is also safe with respect to the course of pregnancies and the health of offspring. Both protocols developed so far, the single dose and multiple dose antagonist protocol, are comparable, utilizing data from the large prospective phase IIIb studies. Although several studies have indicated a slight reduction in pregnancy rate with GnRH antagonists as compared with agonists, this problem may be rectified by developing flexible antagonist regimens designed for individual patients. Introducing flexible GnRH antagonist regimens should be the area of research in the near future.

GnRH antagonists in the treatment of infertility

GnRH analogues were introduced into clinical practice more than 20 years ago. The recent development of new GnRH antagonists (GnRHant) has revolutionized the treatment protocols of infertility. Ovarian stimulation has become easier, safer and more convenient for patients. This review presents data on the physiological background of GnRH and its analogues--agonists as well as antagonists--and highlights the different aspects of the clinical use of these substances. Two protocols, the single dose and multiple dose protocol are available and lead to comparable results. Data from prospective, randomized trials as well as meta-analyses suggest, that a more tailored, individualized approach concerning the day of administration of GnRHant may lead to more favorable results with regard to ovarian response, implantation and pregnancy rates. Possible negative effects of GnRHant, mainly based on in vitro models are discussed. The outcome of children born after GnRHant use has shown, that this medication is safe. On the whole, the use of GnRHant is advantageous as compared to the traditional way of ovarian stimulation, i.e., the GnRH agonist long protocol. However, especially the effectiveness of these compounds will have to be clarified in the near future by carefully designed prospective, randomized studies.

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.

The gonadotrophin-releasing hormone antagonist ganirelix--history and introductory data

The gonadotrophin-releasing hormone antagonist ganirelix has recently become available to clinicians. Its indication, prevention of premature luteinizing hormone surges in assisted reproduction programmes, has been investigated extensively in numerous studies. This article summarizes the major results from pharmacokinetics studies, a double-blind dose-finding trial and three large-scale phase III randomized clinical trials, comparing ganirelix and the most commonly used gonadotrophin-releasing hormone agonists, buserelin,leuprolide and triptorelin, in a long protocol. It is concluded that controlled ovarian hyperstimulation with ganirelix offers significant advantages in terms of convenience of treatment as reflected in a considerably reduced treatment period.Safety and tolerance as well as overall clinical outcome are good.