Gonadotropin-releasing hormone agonist versus human chorionic gonadotropin as a trigger of ovulation in polycystic ovarian disease gonadotropin hyperstimulated cycles

Short versus extended progesterone supplementation for luteal phase support in fresh IVF cycles: a systematic review and meta-analysis

This review and meta-analysis aim to assess the effect of prolonged progesterone support on pregnancy outcomes in women undergoing fresh embryo transfer after IVF/intracytoplasmic sperm injection (ICSI). Two independent authors searched Embase, MEDLINE and grey literature from inception to January 2019 for randomized controlled trials (RCT) of prolonged progesterone support versus early cessation. Risk of bias was assessed. Outcome measures were live birth, miscarriage and ongoing pregnancy rate. The study was registered with PROSPERO (CRD42018088605). Seven trials involving 1627 participants were included: three reported live birth rate (672/830), seven the miscarriage rate (178/1627) and seven the ongoing pregnancy rate (1351/1627). Clinical outcomes were similar between early progesterone cessation versus progesterone continuation: live birth rate (risk ratio [RR] 0.94, 95% confidence interval [CI] 0.88-1.00), miscarriage rate (RR 0.91, 95% CI 0.69-1.20) and ongoing pregnancy rate (RR 0.98, 95% CI 0.91-1.05). Ongoing pregnancy rates were similar when analyses were restricted to those with cessation of progesterone on the day of a positive human chorionic gonadotrophin (RR 0.93, 95% CI 0.83-1.06). This meta-analysis suggests that prolonged progesterone support may be unnecessary after fresh embryo transfer. Further larger RCT would be useful to corroborate and lead to standardized duration of progesterone luteal phase support across IVF/ICSI centres.

Resurgence of Minimal Stimulation In Vitro Fertilization with A Protocol Consisting of Gonadotropin Releasing Hormone-Agonist Trigger and Vitrified-Thawed Embryo Transfer

Minimal stimulation in vitro fertilization (mini-IVF) consists of a gentle controlled ovarian stimulation that aims to produce a maximum of five to six oocytes. There is a misbelief that mini-IVF severely compromises pregnancy and live birth rates. An appraisal of the literature pertaining to studies on mini-IVF protocols was performed. The advantages of minimal stimulation protocols are reported here with a focus on the use of clomiphene citrate (CC), gonadotropin releasing hormone (GnRH) ago- nist trigger for oocyte maturation, and freeze-all embryo strategy. Literature review and the author’s own center data suggest that minimal ovarian stimulation protocols with GnRH agonist trigger and freeze-all embryo strategy along with single embryo transfer produce a reasonable clinical pregnancy and live birth rates in both good and poor responders. Additionally, mini-IVF offers numerous advantages such as: i. Reduction in cost and stress with fewer office visits, needle sticks, and ultrasounds, and ii. Reduction in the incidence of ovarian hyperstimulation syndrome (OHSS). Mini-IVF is re-emerging as a solution for some of the problems associated with conventional IVF, such as OHSS, cost, and patient discomfort.

WITHDRAWN: Gonadotrophin therapy for ovulation induction in subfertility associated with polycystic ovary syndrome

This review has been replaced by a review entitled 'Gonadotrophins for ovulation induction in women with polycystic ovarian syndrome'.

The editorial group responsible for this previously published document have withdrawn it from publication.

Gonadotropin-releasing hormone agonist versus HCG for oocyte triggering in antagonist-assisted reproductive technology

BACKGROUND

Human chorionic gonadotropin (HCG) is routinely used for final oocyte maturation triggering in in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) cycles, but the use of HCG for this purpose may have drawbacks. Gonadotropin-releasing hormone (GnRH) agonists present an alternative to HCG in controlled ovarian hyperstimulation (COH) treatment regimens in which the cycle has been down-regulated with a GnRH antagonist. This is an update of a review first published in 2010.

OBJECTIVES

To evaluate the effectiveness and safety of GnRH agonists in comparison with HCG for triggering final oocyte maturation in IVF and ICSI for women undergoing COH in a GnRH antagonist protocol.

SEARCH METHODS

We searched databases including the Menstrual Disorders and Subfertility Group (MDSG) Specialised Register of Controlled Trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, the Cumulative Index to Nursing and Allied Health Literature (CINAHL) and trial registers for published and unpublished articles (in any language) on randomised controlled trials (RCTs) of gonadotropin-releasing hormone agonists versus HCG for oocyte triggering in GnRH antagonist IVF/ICSI treatment cycles. The search is current to 8 September 2014.

SELECTION CRITERIA

RCTs that compared the clinical outcomes of GnRH agonist triggers versus HCG for final oocyte maturation triggering in women undergoing GnRH antagonist IVF/ICSI treatment cycles were included.

DATA COLLECTION AND ANALYSIS

Two or more review authors independently selected studies, extracted data and assessed study risk of bias. Treatment effects were summarised using a fixed-effect model, and subgroup analyses were conducted to explore potential sources of heterogeneity. Treatment effects were expressed as mean differences (MDs) for continuous outcomes and as odds ratios (ORs) for dichotomous outcomes, together with 95% confidence intervals (CIs). Primary outcomes were live birth and rate of ovarian hyperstimulation syndrome (OHSS) per women randomised. Grades of Recommendation, Assessment, Development and Evaluation (GRADE) methods were used to assess the quality of the evidence for each comparison.

MAIN RESULTS

We included 17 RCTs (n = 1847), of which 13 studies assessed fresh autologous cycles and four studies assessed donor-recipient cycles. In fresh autologous cycles, GnRH agonists were associated with a lower live birth rate than was seen with HCG (OR 0.47, 95% CI 0.31 to 0.70; five RCTs, 532 women, I(2) = 56%, moderate-quality evidence). This suggests that for a woman with a 31% chance of achieving live birth with the use of HCG, the chance of a live birth with the use of an GnRH agonist would be between 12% and 24%.In women undergoing fresh autologous cycles, GnRH agonists were associated with a lower incidence of mild, moderate or severe OHSS than was HCG (OR 0.15, 95% CI 0.05 to 0.47; eight RCTs, 989 women, I² = 42%, moderate-quality evidence). This suggests that for a woman with a 5% risk of mild, moderate or severe OHSS with the use of HCG, the risk of OHSS with the use of a GnRH agonist would be between nil and 2%.In women undergoing fresh autologous cycles, GnRH agonists were associated with a lower ongoing pregnancy rate than was seen with HCG (OR 0.70, 95% CI 0.54 to 0.91; 11 studies, 1198 women, I(2) = 59%, low-quality evidence) and a higher early miscarriage rate (OR 1.74, 95% CI 1.10 to 2.75; 11 RCTs, 1198 women, I² = 1%, moderate-quality evidence). However, the effect was dependent on the type of luteal phase support provided (with or without luteinising hormone (LH) activity); the higher rate of pregnancies in the HCG group applied only to the group that received luteal phase support without LH activity (OR 0.36, 95% CI 0.21 to 0.62; I(2) = 73%, five RCTs, 370 women). No evidence was found of a difference between groups in risk of multiple pregnancy (OR 3.00, 95% CI 0.30 to 30.47; two RCTs, 62 women, I(2) = 0%, low-quality evidence).In women with donor-recipient cycles, no evidence suggested a difference between groups in live birth rate (OR 0.92, 95% CI 0.53 to 1.61; one RCT, 212 women) or ongoing pregnancy rate (OR 0.88, 95% CI 0.58 to 1.32; three RCTs, 372 women, I² = 0%). We found evidence of a lower incidence of OHSS in the GnRH agonist group than in the HCG group (OR 0.05, 95% CI 0.01 to 0.28; three RCTs, 374 women, I² = 0%).The main limitation in the quality of the evidence was risk of bias associated with poor reporting of methods in the included studies.

AUTHORS' CONCLUSIONS

Final oocyte maturation triggering with GnRH agonist instead of HCG in fresh autologous GnRH antagonist IVF/ICSI treatment cycles prevents OHSS to the detriment of the live birth rate. In donor-recipient cycles, use of GnRH agonists instead of HCG resulted in a lower incidence of OHSS, with no evidence of a difference in live birth rate.Evidence suggests that GnRH agonist as a final oocyte maturation trigger in fresh autologous cycles is associated with a lower live birth rate, a lower ongoing pregnancy rate (pregnancy beyond 12 weeks) and a higher rate of early miscarriage (less than 12 weeks). GnRH agonist as an oocyte maturation trigger could be useful for women who choose to avoid fresh transfers (for whatever reason), women who donate oocytes to recipients or women who wish to freeze their eggs for later use in the context of fertility preservation.

Ovarian stimulation for IVF and endometrial receptivity--the missing link

The contemporary approach to ovarian stimulation for IVF treatment results in supraphysiological concentrations of steroids during the follicular and luteal phases of the menstrual cycle. These sex steroids act directly and indirectly to mature the endometrium, influencing receptivity for implantation. Corpus luteum function is distinctly abnormal in IVF cycles, and therefore luteal support is widely used. Various reasons may underlie the defective luteal phase, including (i) ovarian hyperstimulation per se, (ii) gonadotrophin-releasing hormone (GnRH) analogue co-treatment and (iii) the use of human chorionic gonadotrophin (HCG) to induce final oocyte maturation. The recent introduction of GnRH antagonist co-treatment for the prevention of a premature LH rise during the late follicular phase allows for different approaches to ovarian stimulation for IVF. However, a recent meta-analysis showed that implantation rates may be compromised by using GnRH antagonists in currently employed regimens. The development of endometrium receptive to embryo implantation is a complex process and may be altered by inappropriate exposure to sex steroids in terms of timing, duration and magnitude. New approaches to the assessment of endometrial receptivity are now required. Novel approaches to ovarian stimulation aimed at adjusted GnRH antagonist regimens and achieving a more physiological luteal phase endocrinology are now appearing in the literature and may represent an important step in the improvement of the overall health economics of IVF.

Gonadotropin-releasing hormone agonist versus HCG for oocyte triggering in antagonist assisted reproductive technology cycles

BACKGROUND

Gonadotropin-releasing hormone (GnRH) antagonist protocols for pituitary down regulation in in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) allow the use of GnRH agonists for triggering final oocyte maturation. Currently, human chorionic gonadotropin (HCG) is still the standard medication for this purpose. The effectiveness of triggering with a GnRH agonist compared to HCG measured as pregnancy and ovarian hyperstimulation(OHSS) rates are unknown.

OBJECTIVES

To compare the effectiveness of a GnRH agonist with HCG for triggering final oocyte maturation in IVF and ICSI patients undergoing controlled ovarian hyperstimulation in a GnRH antagonist protocol followed by embryo transfer. 

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE , EMBASE, the National Research Register, the Medical Research Council's Clinical Trials Register, and the NHS Centre for Reviews and Dissemination database. We also examined the reference lists of all known primary studies and review articles, citation lists of relevant publications and abstracts of major scientific meetings.

SELECTION CRITERIA

All randomised controlled studies (RCTs) reporting data comparing clinical outcomes for women undergoing IVF and ICSI cycles and using a GnRH agonist in comparison with HCG for final oocyte maturation triggering.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

We identified 11 RCTs (n = 1055). Eight studies assessed fresh autologous cycles and three studies assessed donor-recipient cycles. In fresh-autologous cycles, GnRH agonist was less effective than HCG in terms of the live birth rate per randomised woman (OR 0.44, 95% CI 0.29 to 0.68; 4 RCTs) and ongoing pregnancy rate per randomised woman (OR 0.45, 95% CI 0.31 to 0.65; 8 RCTs). For a group with a 30% live birth or ongoing pregnancy rate using HCG, the rate would be between 12% and 22% using an GnRH agonist. Moderate to severe ovarian hyperstimulation syndrome (OHSS) incidence per randomised woman was significantly lower in the GnRH agonist group compared to the HCG group (OR 0.10, 95% CI 0.01 to 0.82; 5 RCTs). For a group with a 3% OHSS rate using HCG the rate would be between 0% and 2.6% using GnRH agonist. In donor recipient cycles, there was no evidence of a statistical difference in the live birth rate per randomised woman (OR 0.92, 95% CI 0.53 to 1.61; 1 RCT).

AUTHORS' CONCLUSIONS

We do not recommend that GnRH agonists be routinely used as a final oocyte maturation trigger in fresh autologous cycles because of lowered live birth rates and ongoing pregnancy rates. An exception could be made for women with high risk of OHSS, after appropriate counselling.

Gonadotropin-releasing hormone agonist versus HCG for oocyte triggering in antagonist assisted reproductive technology cycles

BACKGROUND

Gonadotropin-releasing hormone (GnRH) antagonist protocols for pituitary down regulation in in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) allow the use of GnRH agonists for triggering final oocyte maturation. Currently, human chorionic gonadotropin (HCG) is still the standard medication for this purpose. The effectiveness of triggering with a GnRH agonist compared to HCG measured as pregnancy and ovarian hyperstimulation(OHSS) rates are unknown.

OBJECTIVES

To compare the effectiveness of a GnRH agonist with HCG for triggering final oocyte maturation in IVF and ICSI patients undergoing controlled ovarian hyperstimulation in a GnRH antagonist protocol followed by embryo transfer. 

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE , EMBASE, the National Research Register, the Medical Research Council's Clinical Trials Register, and the NHS Centre for Reviews and Dissemination database. We also examined the reference lists of all known primary studies and review articles, citation lists of relevant publications and abstracts of major scientific meetings.

SELECTION CRITERIA

All randomised controlled studies (RCTs) reporting data comparing clinical outcomes for women undergoing IVF and ICSI cycles and using a GnRH agonist in comparison with HCG for final oocyte maturation triggering.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

We identified 11 RCTs (n = 1055). Eight studies assessed fresh autologous cycles and three studies assessed donor-recipient cycles. In fresh-autologous cycles, GnRH agonist was less effective than HCG in terms of the live birth rate per randomised woman (OR 0.44, 95% CI 0.29 to 0.68; 4 RCTs) and ongoing pregnancy rate per randomised woman (OR 0.45, 95% CI 0.31 to 0.65; 8 RCTs). For a group with a 30% live birth or ongoing pregnancy rate using HCG, the rate would be between 12% and 22% using an GnRH agonist. Moderate to severe ovarian hyperstimulation syndrome (OHSS) incidence per randomised woman was significantly lower in the GnRH agonist group compared to the HCG group (OR 0.10, 95% CI 0.01 to 0.82; 5 RCTs). For a group with a 3% OHSS rate using HCG the rate would be between 0% and 2.6% using GnRH agonist. In donor recipient cycles, there was no evidence of a statistical difference in the live birth rate per randomised woman (OR 0.92, 95% CI 0.53 to 1.61; 1 RCT).

AUTHORS' CONCLUSIONS

We do not recommend that GnRH agonists be routinely used as a final oocyte maturation trigger in fresh autologous cycles because of lowered live birth rates and ongoing pregnancy rates. An exception could be made for women with high risk of OHSS, after appropriate counselling.

Triggering ovulation with gonadotropin-releasing hormone agonists does not compromise embryo implantation rates

OBJECTIVE

To evaluate the implant capacity of embryos derived from oocytes matured with a bolus of GnRH agonist.

DESIGN

Donors were randomly assigned to a protocol using either GnRH agonist or recombinant (r) hCG to trigger ovulation. Analysis of variance, Student t test, and Fisher exact test were used where appropriate.

SETTING

Private clinical setting.

PATIENT(S)

Young voluntary donors receiving GnRH agonist (n = 30) or rhCG (n = 30). Eighty-nine patients received oocytes.

INTERVENTION(S)

Controlled ovarian stimulation was carried out with GnRH antagonist and FSH/LH in a step-down protocol. Donors received a single bolus of GnRH agonist (0.2 mg) or rhCG (250 microg). The endometrial tissue of recipient patients was prepared with oral E(2) and P.

MAIN OUTCOME MEASURE(S)

Pregnancy and implantation rates and ovarian hyperstimulation syndrome (OHSS) in an IVF donor program.

RESULT(S)

No significant differences in the number of retrieved oocytes (327 vs. 288), MII oocytes (70% vs. 76%), fertilization (80% vs. 65%,), pregnancy/transfer (55% vs. 59%), and implantation rates (29% vs. 32%) were found between recipients whose embryos originated from donors in whom final oocyte maturation was triggered with GnRH agonist and those whose donors received hCG. Significant differences in luteal phase length (4.16 + 0.70 days vs. 13.63 + 2.12 days) and in OHSS (0/30 vs. 5/30) were seen between donors ovulated with the agonist and the donors in whom ovulation was triggered with hCG.

CONCLUSION(S)

In controlled ovarian stimulation IVF donor cycles, GnRH agonists trigger ovulation and induce luteolysis but do not compromise embryo implantation capacity.

Safety and efficacy of low dose hCG for luteal support after triggering ovulation with a GnRH agonist in cases of polyfollicular development

OBJECTIVE

The use of GnRH agonists instead of hCG to trigger ovulation seems to be an effective way to prevent subsequent hCG induced ovarian hyperstimulation in cases of polyfollicular development. But conflicting results are reported on the efficiency of subsequent luteal support using hCG and/or progesterone supplementation.

STUDY DESIGN

We investigated the efficiency and safety of different luteal support regimes in low dose gonadotropin stimulation non-ivf cycles. A risk for an imminent ovarian hyperstimulation was assumed if preovulatory estradiol levels rose up higher than 700 pg/ml and more than 12 intermediate sized follicles (8-14 mm) were observed. Thirty-six women received 0.5mg Triptorelin subcutaneously to trigger the ovulation inducing LH surge. After randomization, luteal support regimes started on day 2 after the Triptorelin administration with injections every second day five times in all. Group (a) received 5 x 1000 IU hCG, group (b) received 5 x 500 IU hCG, and group (c) received 5 x 250 mg progesterone, intramuscularly. The monitoring of the ovulation period and the subsequent luteal phase included sonographic measurement of ovarian diameter and estimation of LH, FSH, estradiol and progesterone levels 10 and 34 h as well as 8 days after Triptorelin administration.

RESULTS

We could prove ovulation in all women and did not find symptoms of ovarian hyperstimulation in any case. Midluteal controls showed extremely low gonadotropins in all groups indicating a long lasting pituitary down regulation after one injection of 0.5 mg Triptorelin. We found high normal sex steroid levels in both hCG groups. The progesterone group displayed a marked luteal phase defect with low levels of progesterone and estradiol in all cases.

CONCLUSION

The use of GnRH agonist in cases of polyfollicular development is capable to induce ovulation without a subsequent ovarian enlargement and/or any sign of hyperstimulation syndrome. Luteal support by low dose hCG does not counteract the benefit of GnRH agonist in preventing an ovarian hyperstimulation syndrome, but seems to remedy at least in part the possible deleterious effects of GnRH agonists on luteal functionality.

GnRH agonist for triggering final oocyte maturation in the GnRH antagonist ovarian hyperstimulation protocol: a systematic review and meta-analysis

Triggering final oocyte maturation with GnRH agonist during ovarian stimulation is feasible when inhibition of premature LH surge is performed with GnRH antagonists, and we aimed to systematically collate evidence on the clinical efficacy of GnRH agonist triggering in patients undergoing assisted reproduction in GnRH antagonist protocols. Twenty-three publications were identified by a comprehensive literature search that included PubMed, Embase and the Cochrane Library. Three publications out of 23 fulfilled the inclusion criteria for meta-analysis, which were (i) prospective, randomized controlled study design; (ii) stimulation with gonadotropins for induction of multifollicular development; (iii) suppression of endogenous LH by a GnRH antagonist; (iv) triggering of final oocyte maturation with GnRH agonist; (v) control group randomized to receive HCG for final oocyte maturation and (vi) any means of luteal phase support other than HCG. The participants were normoovulatory women undergoing IVF. The outcomes assessed were clinical pregnancy per randomized patient; number of oocytes retrieved; proportion of metaphase II oocytes; fertilization rate; embryo quality score; first trimester abortion rate; ovarian hyperstimulation syndrome (OHSS) incidence. Results are presented as combined standardized differences of the mean and combined odds ratios, as appropriate, with 95% confidence intervals. No significant difference was found for the number of oocytes retrieved (-0.94, -0.33-0.14), proportion of metaphase II oocytes (-0.03, -0.58-0.52), fertilization rate (0.15, -0.09-0.38) or embryo quality score (0.05, -0.18-0.29). No OHSS occurred in two of the studies, whereas in one study OHSS incidence was not reported. Thus from the available data, no conclusion can be drawn as regards OHSS incidence after GnRH agonist triggering. In comparison to HCG, GnRH agonist administration is associated with a significantly reduced likelihood of achieving a clinical pregnancy (0.21, 0.05-0.84; P = 0.03). The odds of first trimester pregnancy loss is increased after GnRH agonist triggering; however, the confidence interval crosses unity (11.51, 0.95-138.98; P = 0.05). In conclusion, the use of GnRH agonist to trigger final oocyte maturation in IVF, where inhibition of premature LH surge is achieved with GnRH antagonists, yields a number of oocytes capable to undergo fertilization and subsequent embryonic cleavage, which is comparable to that achieved with HCG. However, the likelihood of an ongoing clinical pregnancy after GnRH agonist triggering is significantly lower as compared to standard HCG treatment.

Ovulation induction

Anovulation, a common cause of female infertility, is a highly curable condition. Presented here is a simple treatment-orientated diagnostic scheme. Anovulatory women with low endogenous oestradiol and follicle stimulating hormone (FSH) are treated with either pulsatile gonadotrophin releasing hormone (GnRH) or gonadotropins, and women with eu-oestrogenic anovulation (mostly with polycystic ovarian syndrome; PCOS) have first-line treatment with clomiphene citrate (CC), possibly with metformin. If CC fails, FSH is administered using a chronic low-dose protocol with small incremental dose rises. A comparison of urinary with recombinant and pure FSH with luteinising hormone (LH) containing gonadotropins is made. Recombinant products are purer and more convenient for use but are expensive. LH content has little impact except in hypogonadotropic hypogonadism or severe pituitary suppression with GnRH analogues. Aromatase inhibitors, recombinant LH and long-acting FSH may find a future place in the armamentarium.

Luteal phase defects following agonist-triggered ovulation: a patient-dependent response

The luteal phase (LP) of patients receiving triptorelin 0.1 mg to trigger ovulation was studied. Patients not pregnant in the first cycle with 0.1 mg were randomized into different groups for a second cycle: 0.1 mg again for patients who experienced a normal LP (group 1); patients affected with LP disorders were randomized into the following groups: 0.1 mg again (group 2); increasing dosage of triptorelin 0.5 mg once (group 3) or 0.1 mg three times (group 4); luteal support either with oral micronized progesterone (group 5) or human chorionic gonadotrophin (HCG) 1500 IU (group 6). Ovulation occurred in all cycles, but an inadequate LP was observed in 34.4% of the non-conceptional cycles. Patients demonstrating a normal LP as well as those affected with luteal disorders in their first cycle showed the same luteal pattern in their consecutive cycles triggered in the same way. In defective LP patients, increasing or repeating triptorelin doses did not restore the luteal phase or the pregnancy rate, both returning closer to normal after luteal support. Defective LP observed after agonist-triggered ovulation do not occur at random; therefore this patient-dependent response may be related to the personal characteristics of each patient's pre-ovulatory physiological surge profile.

Luteolysis induced by a gonadotropin-releasing hormone agonist is the key to prevention of ovarian hyperstimulation syndrome

OBJECTIVE

To review the available knowledge on the use of GnRH agonist for ovulation triggering as a means to prevent ovarian hyperstimulation syndrome (OHSS).

DESIGN(S)

Review of pertinent English language studies published over the past 15 years.

RESULT(S)

The available literature suggests that while GnRH agonist effectively induces final oocyte maturation and ovulation, it also completely and reliably prevents clinically significant OHSS. The mechanism of action in the context of OHSS prevention involves complete, quick, and irreversible luteolysis

CONCLUSION(S)

Controlled ovarian stimulation protocols based on GnRH antagonist to prevent premature LH rise and GnRH agonist for ovulation triggering provide a safe and OHSS-free clinical environment. Adequate luteal support compensates for luteolysis and assures good clinical outcome. The fertility community is urged to adopt these protocols. This will make OHSS a disease of the past.

Use of gonadotrophin-releasing hormone agonists to trigger ovulation

The introduction of gonadotrophin-releasing hormone (GnRH) agonists combined with gonadotrophins is considered to be one of the most significant advances in the development of in vitro fertilization (IVF) treatment. However, ovarian hyperstimulation syndrome (OHSS) remains a significant complication of controlled ovarian hyperstimulation. One possible strategy to reduce the risk of this complication would be the use of GnRH agonists instead of human chorionic gonadotrophin (hCG) to trigger the final stages of oocyte maturation. GnRH agonists are able to induce an endogenous surge of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) and the effect may be more physiological than that of exogenous hCG. Several uncontrolled and controlled clinical studies have confirmed the efficacy of GnRH agonists for triggering ovulation, and pregnancy rates are comparable to those achieved with hCG. The incidence of OHSS appears to be decreased, but larger controlled studies are required to confirm this observation. The recent introduction of GnRH antagonists has led to renewed interest in the use of GnRH agonists to induce final oocyte maturation. An international multicentre randomized controlled trial has been completed recently comparing the efficacy of GnRH agonist with hCG for triggering ovulation in women undergoing controlled ovarian hyperstimulation using the GnRH antagonist ganirelix for pituitary suppression. The aim of the study was to determine the efficacy of the novel protocol for ovarian stimulation before IVF, in terms of pregnancy outcomes and the prevention of OHSS.

[Comparison of different protocols of ovulation induction, by GnRH agonists and chorionic gonadotropin]

OBJECTIVE

The aim of this study was to determine the best way of using a gonadotropin-releasing hormone agonist (GnRHa) for triggering ovulation and to analyse the reasons for short luteal phases.

MATERIALS AND METHODS

Thirteen different regimens of GnRH-a administration were used to trigger ovulation using different dosages and either one, two or three administrations: triptorelin, buserelin spray, buserelin subcutaneously, leuprolide and nafarelin in 231 treatment cycles. Pregnancy rate and luteal phase duration were compared with those of a control group for whom ovulation was triggered with hCG.

RESULTS

Ovulation with supraphysiologic elevation of both FSH and LH was achieved in the 13 GnRHa groups. For the five main groups analysed, GnRHa produced shorter and inadequate luteal phases than did hCG but no difference was found between agonists. Pregnancy rates were not statistically different between the agonist groups or in comparison with the hCG group.

CONCLUSION

The use of GnRHa to trigger ovulation is efficient, despite short luteal phases, and has proven its utility in comparison with hCG. As the different modes of stimulation appear to yield comparable results, the cost of treatment should be a significant element to take into consideration.

Use of a single bolus of GnRH agonist triptorelin to trigger ovulation after GnRH antagonist ganirelix treatment in women undergoing ovarian stimulation for assisted reproduction, with special reference to the prevention of ovarian hyperstimulation syndrome: preliminary report: short communication

A new treatment option for patients undergoing ovarian stimulation is the gonadotrophin-releasing hormone (GnRH) antagonist protocol, with the possibility to trigger a mid-cycle LH surge using a single bolus of GnRH agonist, reducing the risk of developing ovarian hyperstimulation syndrome (OHSS) in high responders and the chance of cycle cancellation. This report describes the use of 0.2 mg triptorelin (Decapeptyl) to trigger ovulation in eight patients who underwent controlled ovarian hyperstimulation with recombinant FSH (rFSH, Puregon) and concomitant treatment with the GnRH antagonist ganirelix (Orgalutran) for the prevention of premature LH surges. All patients were considered to have an increased risk for developing OHSS (at least 20 follicles > or =11 mm and/or serum oestradiol at least 3000 pg/ml). On the day of triggering the LH surge, the mean number of follicles > or =11 mm was 25.1 +/- 4.5 and the median serum oestradiol concentration was 3675 (range 2980-7670) pg/ml. After GnRH agonist injection, endogenous serum LH and FSH surges were observed with median peak values of 219 and 19 IU/l respectively, measured 4 h after injection. The mean number of oocytes obtained was 23.4 +/- 15.4, of which 83% were mature (metaphase II). None of the patients developed any signs or symptoms of OHSS. So far, four clinical pregnancies have been achieved from the embryos obtained during these cycles, including the first birth following this approach. It is concluded that GnRH agonist effectively triggers an endogenous LH surge for final oocyte maturation after ganirelix treatment in stimulated cycles. Our preliminary results suggest that this regimen may prove effective in triggering ovulation and could be said to prevent OHSS in high responders. The efficacy and safety of such new treatment regimen needs to be established in comparative randomized studies.

Gonadotrophin therapy for ovulation induction in subfertility associated with polycystic ovary syndrome

BACKGROUND

Approximately 15% of patients with PCOS remain anovulatory despite treatment with oral anti-oestrogen medications such as clomiphene citrate. In addition, about half of women with PCOS ovulating on anti-oestrogen treatment fail to conceive. Gonadotrophin stimulation is the next step in treatment for women who are "clomiphene resistant", however, results of gonadotrophin stimulation in women with PCOS are less successful. In PCOS associated with hypersecretion of LH, purified urinary follicle-stimulating hormone (u-FSH) preparations have theoretical advantages over the use of human menopausal gonadotrophin (hMG) preparations (containing both FSH and LH), but whether this claimed advantage extends into clinical practice remains uncertain. In addition, the use of gonadotrophin-releasing hormone analogues (GnRH-a) to produce pituitary desensitisation prior to ovulation induction in PCOS has been claimed to increase the success rates of treatment as well as reduce complications such as OHSS and multiple pregnancy. Gonadotrophin preparations have also been administered via different routes (intramuscular or subcutaneous), or using different stimulation regimens and protocols (step-up or standard) in an attempt to improve efficacy.

OBJECTIVES

To determine the effectiveness of urinary-derived gonadotrophins as ovulation induction agents in patients with PCOS trying to conceive. In particular, to assess the effectiveness of (1) different gonadotrophin preparations, (2) the addition of a gonadotrophin-releasing hormone agonist (GnRH-a) to gonadotrophin stimulation and (3) different modalities of gonadotrophin administration.

SEARCH STRATEGY

The search strategy to identify RCTs consisted of (1) the Group's Specialised Register of Controlled Trials using the search strategy developed for the Menstrual Disorders and Subfertility Group as a whole (see the Review Group details for more information), (2) additional specific electronic Medline searches and (3) bibliographies of identified studies and narrative reviews.

SELECTION CRITERIA

RCTs in which urinary-derived gonadotrophins were used for ovulation induction in patients with primary or secondary subfertility attributable to PCOS.

DATA COLLECTION AND ANALYSIS

Twenty three RCTs were identified, 9 of which were excluded from analysis. The data were extracted independently by 2 authors. The following criteria were assessed: (1) the methodological characteristics of the trials, (2) the baseline characteristics of the studied groups and (3) the outcomes of interest: pregnancy rate (per cycle), ovulation rate (per cycle), miscarriage rate (per pregnancy), multiple pregnancy rate (per pregnancy), overstimulation rate (per cycle) and ovarian hyperstimulation syndrome (OHSS) rate (per cycle). Where suitable, meta-analysis was performed using Peto's OR with 95% CI with the fixed effect Mantel-Haentszel equation.

MAIN RESULTS

(1) A reduction in the incidence of OHSS with FSH compared to hMG in stimulation cycles without the concomitant use of a GnRH-a (OR 0.20; 95% CI 0.08-0.46) and (2) a higher overstimulation rate when a GnRH-a is added to gonadotrophins (OR 3.15; 95% CI 1.48-6.70).

REVIEWER'S CONCLUSIONS

Although 14 RCTs were included in this review, few dealt with the same comparisons, all were small to moderate size and their methodological quality was generally poor. Any conclusions, therefore, remain tentative as they are based on a limited amount of data and will require further RCTs to substantiate them. In none of the comparisons was there a significant improvement in pregnancy rate but this may be due to the lack of power (i.e. insufficient patients randomised to demonstrate a significant difference between treatments). There was a trend towards better pregnancy rates with the addition of a GnRH-a to gonadotrophin stimulation and these interventions warrant further study. Despite theoretical advantages, urinary-derived FSH preparations did not improve pregnancy rates when compared to traditional and cheaper hMG preparations; their only demonstrable benefit was a reduced risk of OHSS in cycles when administered without the concomitant use of a GnRH-a. No conclusions can be drawn on miscarriage and multiple pregnancy rates due to insufficient reporting of these outcomes in the trials.

Polycystic ovarian disease: current insights into an old problem

Recent studies have led to significant advances in the understanding of the pathogenesis of polycystic ovary syndrome (PCOS), as well as to improvements in the treatment of the commonly associated symptoms. New data continue to implicate etiologic alterations in the hypothalamic-pituitary axis, beginning in the perimenarcheal period, as well as derangements in insulin and insulin-like growth factor metabolism. Current observations also support a role for an increase in adrenal androgen production and an increase in adrenal sensitivity to trophic hormone stimulation in the development of PCOS. Therapeutic regimens for those patients unsuccessfully treated with traditional approaches have been further validated, including the use of flutamide or gonadotropin-releasing hormone agonist-steroidal "add back" for the treatment of hirsutism. Novel approaches to the treatment of infertility are likewise discussed.