GnRH antagonists: do they open new pathways to safer treatment in assisted reproductive techniques?

Comparison of results of cycles treated with modified mild protocol and short protocol for ovarian stimulation

The ovarian stimulation has been applied in order to increase the number of oocytes to compensate for the poor results of in vitro fertilization, allowing the selection of one or more embryos to be transferred. Our aim is to compare the results obtained in IVF/ICSI cycles using the short protocol for controlled ovarian stimulation to the results from the modified mild protocol used in our department. A total of 240 cycles were conducted from January 2010 to December 2011. When comparing both protocols, it could be observed that there was a significant difference in the quantity of gonadotropins doses in the mild protocol and in the short protocol. No significant difference was observed regarding pregnancy rates per cycle, 22% and 26.2%, in short and mild protocols, respectively. The protocols of controlled ovarian stimulation are often associated with high risk of complications such as ovarian hyperstimulation syndrome, excessive emotional stress, high rates of treatment dropouts, and abdominal discomfort. With the data obtained in this study, one can conclude that there are less risks and complications for the patient when using the mild stimulation protocol. It was also observed that in this group there was a slightly higher rate.

Mild ovarian stimulation for IVF

BACKGROUND

Mild ovarian stimulation for in vitro fertilization (IVF) aims to achieve cost-effective, patient-friendly regimens which optimize the balance between outcomes and risks of treatment.

METHODS

Pubmed and Medline were searched up to end of January 2008 for papers on ovarian stimulation protocols for IVF. Additionally, references to related studies were selected wherever possible.

RESULTS

Studies show that mild interference with the decrease in follicle-stimulating hormone levels in the mid-follicular phase was sufficient to override the selection of a single dominant follicle. Gonadotrophin-releasing hormone antagonists compared with agonists reduce length and dosage of gonadotrophin treatment without a significant reduction in the probability of live birth (OR 0.86, 95% CI 0.72-1.02). Mild ovarian stimulation may be achieved with limited gonadotrophins or with alternatives such as anti-estrogens or aromatase inhibitors. Another option is luteinizing hormone or human chorionic gonadotrophin administration during the late follicular phase. Studies regarding these approaches are discussed individually; small sample size of single studies along with heterogeneity in patient inclusion criteria as well as outcomes analysed does not allow a meta-analysis to be performed. Additionally, the implications of mild ovarian stimulation for embryo quality, endometrial receptivity, cost and the psychological impact of IVF treatment are discussed.

CONCLUSIONS

Evidence in favour of mild ovarian stimulation for IVF is accumulating in recent literature. However, further, sufficiently powered prospective studies applying novel mild treatment regimens are required and structured reporting of the incidence and severity of complications, the number of treatment days, medication used, cost, patient discomfort and number of patient drop-outs in studies on IVF is encouraged.

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.

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.

Singleton pregnancies are as affected by ovarian hyperstimulation syndrome as twin pregnancies

The incidence of ovarian hyperstimulation syndrome (OHSS) did not decrease during the 5 years in which single-embryo transfer was introduced; OHSS is not more frequent in twin than in singleton pregnancies.

No influence of body weight on pregnancy rate in patients treated with cetrorelix according to the single- and multiple-dose protocols

The question of whether adjustment to body weight is necessary in in-vitro fertilization (IVF) cycles using GnRH antagonists is currently under discussion. Therefore, a data analysis of five prospective studies using either the single- or the multiple-dose antagonist protocol with cetrorelix (Cetrotide) was performed. The influence of stimulation procedure, gonadotrophins and body weight on pregnancy rate was evaluated in a linear logit model. The effect of the stimulation procedure and body weight on the cumulus-oocyte complex (COC) and follicle number was explored in an ANOVA model. Cetrorelix plasma concentrations were tested for any correlation with body weight. Baseline and outcome parameters in different body weight groups (<50 kg, 50-59 kg, 60-69 kg, 70-79 kg, > or =80 kg) were assessed for human menopausal gonadotrophin and recombinant human FSH stimulation separately. Cetrorelix plasma concentrations were correlated with body weight, but no influence of the type of stimulation or body weight on pregnancy rate was found. Body weight did not influence cetrorelix plasma concentrations. In contrast, body weight significantly influenced the number of retrieved COC as well as the number of follicles on the day of human chorionic gonadotrophin administration. Body weight does not influence the outcome of treatment in cetrorelix cycles.

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.

Reproductive outcome of polycystic ovarian syndrome patients treated with GnRH antagonists and recombinant FSH for IVF/ICSI

The purpose of this prospective study was to assess the reproductive outcome of patients with polycystic ovarian syndrome (PCOS) treated by in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) with recombinant FSH (rFSH) and gonadotrophin releasing hormone (GnRH) antagonists. One hundred and ten patients were evaluated. The starting dose of rFSH was 100 IU in 67 women with body mass index (BMI) </=29 kg/m(2) and 200 IU in 43 women with BMI >29 kg/m(2). GnRH antagonist was started by the detection of a follicle of a 15mm in ultrasound scan. A significantly lower ongoing pregnancy rate per oocyte retrieval (25.6% versus 46.7%, P = 0.04) and a higher occurrence of ovarian hyperstimulation syndrome (16.3% versus 3.0%, P = 0.03) was observed in the group of patients with BMI >29 kg/m(2) as compared with the group of patients with BMI </=29 kg/m(2), respectively. In conclusion, in GnRH antagonist cycles a worse reproductive outcome is expected in PCOS patients with BMI >29 kg/m(2) in whom stimulation is initiated with 200 IU of rFSH as compared with PCOS patients with BMI </=29 kg/m(2) in whom stimulation is initiated with 100 IU of rFSH.