Embryo implantation and GnRH antagonists: the search for the human placental GnRH receptor

Hypothalamic gonadotrophin-releasing hormone (GnRH) plays a major role in the endocrine control of reproduction. Acting through its high affinity receptors on pituitary gonadotrophs, it regulates the secretion of gonadotrophins. In addition, GnRH also functions as a local regulator in a number of other cell lines and tissues, including the placenta. In a manner analogous to hypothalamic GnRH stimulation of LH and FSH from the anterior pituitary, GnRH was found to cause a dose-dependent release of human chorionic gonadotrophin (HCG) from the placenta. So began the search for a putative GnRH receptor in the human placenta. Although early radio-receptor studies reported specific binding, the properties of these 'putative' GnRH binding sites were found to differ significantly from those of their pituitary counterparts in several important respects. This was followed by a series of contradictory reports that led to more questions and opened up avenues for further investigations. Even after nearly two decades of research, the human placental GnRH receptor has not been characterized beyond all reasonable doubt. This review recalls the discovery, the controversies and unanswered questions concerning the human placental GnRH receptor.     

Embryo implantation and GnRH antagonists: embryo implantation: the Rubicon for GnRH antagonists

When gonadotrophin-releasing hormone (GnRH) was discovered, the agonist and antagonist of GnRH were developed to control the release of FSH and LH by the gonadotrophs. More than 10 years of research were needed to develop a GnRH antagonist free of histamine release. Recent studies have shown that these GnRH antagonists are effective in preventing a rise in LH during ovarian stimulation in IVF. However, a decrease in ongoing pregnancies seems to suggest that implantation rates per transferred embryo are reduced in GnRH antagonist-stimulated cycles. In my opinion, these data highlight an area less well known to clinicians: the role of the GnRH antagonist at the cellular level in extrapituitary tissues. There are sufficient data in the literature suggesting that GnRH antagonist is an inhibitor of the cell cycle by decreasing the synthesis of growth factors. Given that, for folliculogenesis, blastomere formation and endometrium development, mitosis is everything; the interaction between the GnRH antagonist and the GnRH receptor (present in all these cells and tissues) may compromise the mitotic programme of these cells. This is the Rubicon for the GnRH antagonist: to demonstrate irrevocably that, at the minimal doses necessary to suppress LH release, it does not affect processes such as implantation, embryo development and folliculogenesis.     

Embryo implantation and GnRH antagonists: ovarian actions of GnRH antagonists

The gonadotrophin-releasing hormone (GnRH) antagonists, cetrorelix and ganirelix, have both been approved for ovarian stimulation to prevent a premature LH surge. Since GnRH receptors and their gene expression have been detected in human ovary, concern has risen over whether GnRH antagonists might affect ovarian function. Three large trials which compared GnRH agonists (used in the standard protocol worldwide), with the new antagonist treatment found no significant differences concerning the most important goals, e.g. pregnancy rate, fertilization and quality of oocytes. However, the concentration of oestradiol, and the pregnancy and implantation rates were lower in GnRH antagonist-treated patients. These findings again fuelled the debate about the possible extrapituitary effects of GnRH antagonists. Here, we review the conflicting data in the literature on the ovarian effects of GnRH antagonists and discuss our own results. In our view, it is unlikely that GnRH antagonists have a relevant impact on ovarian steroidogenesis and function; however, GnRH antagonists may exert other effects on the ovary.     

Beneficial effect of luteal-phase GnRH agonist administration on embryo implantation after ICSI in both GnRH agonist- and antagonist-treated ovarian stimulation cycles

BACKGROUND: GnRH agonist was recently suggested as a novel luteal-phase support that may act at different levels, including the pituitary gonadotrophs, the endometrium and the embryo itself. This prospective randomized study evaluates the effect of GnRH agonist administered in the luteal phase on ICSI outcomes in both GnRH agonist- and GnRH antagonist-treated ovarian stimulation protocols. METHODS: Six hundred women about to undergo ovarian stimulation for ICSI (300 using a long GnRH agonist protocol and 300 using a GnRH antagonist protocol) were enrolled in this study. Patients treated with each of these two protocols were randomly assigned to receive a single injection of GnRH agonist or placebo 6 days after ICSI. Implantation and live birth rates were the primary outcomes. RESULTS: Administration of 0.1 mg of GnRH agonist triptorelin on day 6 after ICSI led to a significant improvement of implantation and live birth rates after ICSI as compared with placebo. In GnRH antagonist-treated ovarian stimulation cycles, luteal-phase GnRH agonist also increased ongoing pregnancy rate. Moreover, luteal-phase GnRH agonist administration increased luteal-phase serum HCG, estradiol and progesterone concentrations in both ovarian stimulation regimens. CONCLUSIONS: Luteal-phase GnRH agonist administration enhances ICSI clinical outcomes after GnRH agonist- and GnRH antagonist-treated ovarian stimulation cycles, possibly by a combination of effects on the embryo and the corpus luteum.     

GnRH agonist versus GnRH antagonist in oocyte donation cycles: a prospective randomized study

BACKGROUND: The specific role of LH in folliculogenesis and oocyte maturation is unclear. GnRH antagonists, when administered in the late follicular phase, induce a sharp decrease in serum LH which may be detrimental for IVF outcome. This study was performed to evaluate whether the replacement of GnRH agonist (triptorelin) by a GnRH antagonist (ganirelix; NV Organon) in oocyte donation cycles has any impact on pregnancy and implantation rates. METHODS: A total of 148 donor IVF cycles was randomly assigned to use either a GnRH antagonist daily administered from the 8th day of stimulation (group I) or a GnRH agonist long protocol (group II) for the ovarian stimulation of their donors. The primary endpoints were the pregnancy and the implantation rates. RESULTS: The clinical pregnancy rate per transfer (39.72%, 29/73 versus 41.33%, 31/75) based on transvaginal scan findings at 7 weeks of gestation, the implantation rate (23.9 versus 25.4%) and the first trimester abortion rate (10.34 versus 12.90%) were similar in the two groups. CONCLUSION: In oocyte donation cycles the replacement of GnRH agonist by a GnRH antagonist appears to have no impact on the pregnancy and implantation rates when its administration starts on day 8 of stimulation.     

Comparison between a GnRH antagonist and a GnRH agonist flare-up protocol in oocyte donors: a randomized clinical trial

BACKGROUND: Little information is available on the outcome of controlled ovarian hyperstimulation (COH) using GnRH antagonist in oocyte donation cycles especially in comparison with the short GnRH agonist protocol. This study was aimed at comparing the two stimulation protocols in oocyte donation (OD) cycles. METHODS: A total of 113 donors randomly received COH using either GnRH antagonist or GnRH agonist. The primary endpoint was the mean number of mature oocytes retrieved per started donor cycle. Secondary endpoints were the mean number of cumulus-oocyte-complexes (COCs) retrieved, the mean proportion of mature oocytes, pregnancy and implantation rates in recipients. RESULTS: Oocytes were distributed to 166 recipients. The mean number (+/- SD) of COC (11.6 +/- 5.8 versus 12.1 +/- 6.7), mature oocytes (8.4 +/- 4.4 versus 8.9 +/- 5.3) and the proportion of mature oocytes (70.8 versus 75.7%) retrieved per started donor cycle were similar in the antagonist and agonist groups, respectively. The implantation rate (26.1 versus 30.1%), clinical (40.2 versus 45.6%) and ongoing pregnancy rate per recipient cycle (32.2 versus 37.9%) were comparable in antagonist and agonist protocols, respectively. CONCLUSIONS: Similar mean number of mature oocytes and comparable pregnancy rates are achieved after OD in which donors received COH using GnRH antagonist or short GnRH agonist protocols.     

GnRH antagonist versus long GnRH agonist protocol in poor responders undergoing IVF: a randomized controlled trial

BACKGROUND. This is the first published report of a prospective, randomized, controlled trial comparing a fixed, multi-dose GnRH antagonist protocol with a long GnRH agonist protocol in poor responders undergoing IVF. METHODS. Sixty-six poor responders were randomized into two groups: the study group received 0.25 mg of cetrorelix daily starting on day 6 of stimulation; the control group received 600 microg of buserelin acetate daily starting in the mid-luteal phase of the preceding cycle. Both groups were given a fixed dose of recombinant FSH (300 IU daily) for stimulation. RESULTS. There were no significant differences in the cycle cancellation rates, duration of stimulation, consumption of gonadotrophins, and mean numbers of mature follicles, oocytes and embryos obtained. The implantation rates were similar, but the number of embryos transferred was significantly higher for the antagonist group (2.32 +/- 0.58 versus 1.50 +/- 0.83; P = 0.01). The pregnancy rates were also higher in the antagonist group, but the difference was not statistically significant. CONCLUSION. A fixed multi-dose GnRH antagonist protocol is feasible for patients who are poor responders on a long agonist protocol; however, our study failed to demonstrate an overall improvement in ovarian responsiveness. Clinical outcomes may be improved by developing more flexible antagonist regimens, an approach that requires further evaluation.     

GnRH拮抗剂与GnRH激动剂短方案IVF-ET结局的比较

目的比较GnRH antagonist与GnR Hagonist短方案的IVF-ET结局。方法2006年8月至2007年8月GnR Hantagonist治疗组54人和GnR Hagonist短方案对照组132人,记录促性腺激素的用量及其用药天数、hCG日子宫内膜厚度和激素水平、获卵数、受精率、卵裂率、优胚率、妊娠率和OHSS发生率等指标。结果两组促性腺激素的用量及其用药天数、获卵数、受精率、卵裂率、着床率和妊娠率相比较均无显著差异（P〉0.05）。GnR Hantagonist组在hCG日激素水平低,与对照组比较其差异有统计学意义。结论行GnR Hantagonist方案IVF-ET助孕治疗与传统的GnR Hagonist短方案比较,其hCG日雌激素水平下降可能是OHSS发生率显著下降的主要因素;但卵泡的发育、卵母细胞的受精率、卵裂率及妊娠率和着床率均不受影响。GnR Hantagonist的使用为IVF-ET助孕药物提供了一种新的选择。     

GnRH agonist as luteal phase support in assisted reproduction technique cycles: results of a pilot study

BACKGROUND: The aim of the study was to investigate whether intranasal (IN) administration of a GnRH agonist could provide luteal support in IVF/ICSI patients. METHODS: Controlled ovarian hyperstimulation (COH) was performed using hMG/FSH and a GnRH antagonist. Patients were then randomly allocated to either 10,000 IU hCG, followed by vaginal administration of micronized progesterone (3x 200 mg/day) (group A), or 200 microg IN buserelin followed by either 100 microg every 2 days (group B), or 100 microg every day (group C), or 100 microg twice a day (group D), or 100 microg three times a day (group E). Luteal support was continued for 15 days. RESULTS: Twenty-three patients were randomized. Groups B and C were discontinued prematurely in view of the short luteal phase. The luteal phase was significantly shorter in groups B, C and D, whereas group E was comparable with group A, 13.5 and 13.0 days, respectively. In the mid-luteal phase, median progesterone levels were significantly lower in groups B, C and D, whereas group E was comparable with group A, 68.9 and 98.0 ng/ml, respectively. Estradiol (E2) was significantly reduced in groups B and D but sustained in group E. In the hCG group, LH levels were undetectable (<0.1 IU/l), whereas LH was detectable and significantly higher in groups C, D and E. Two pregnancies were obtained in the hCG group (two of five), one ectopic and one ongoing. Three pregnancies were obtained in group E, one miscarriage and two ongoing twin pregnancies (three of five). CONCLUSION: IN administration of buserelin may be effective in triggering follicular maturation and providing luteal phase support in patients undergoing assisted reproduction techniques (ART).     

A lower ongoing pregnancy rate can be expected when GnRH agonist is used for triggering final oocyte maturation instead of HCG in patients undergoing IVF with GnRH antagonists

BACKGROUND: Eliciting an endogenous LH surge by GnRH-agonist for the induction of final oocyte maturation may be more physiological compared with the administration of HCG. However, the efficacy of this intervention in patients treated for IVF with GnRH antagonists remains to be assessed. METHODS: 106 patients were randomized to receive either 10 000 IU urinary HCG or 0.2 mg Triptorelin for triggering final oocyte maturation. Ovarian stimulation for IVF was performed with a fixed dose of 200 IU recombinant FSH and GnRH antagonist was started on stimulation day 6. Luteal phase was supported with micronized vaginal progesterone and oral estradiol. The study was monitored continuously for safety and stopping rules were established. RESULTS: No significant differences were present in the number of cumulus-oocyte complexes retrieved, in the proportion of metaphase II oocytes, in fertilization rates or in the number and quality of the embryos transferred between the two groups. However, a significantly lower probability of ongoing pregnancy in the GnRH agonist arm prompted discontinuation of the trial, according to the stopping rules established (odds ratio 0.11; 95% confidence interval 0.02-0.52). CONCLUSIONS: Lower probability of ongoing pregnancy can be expected when GnRH agonist is used for triggering final oocyte maturation instead of HCG in patients undergoing ovarian stimulation for IVF with GnRH antagonists.     

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.     

Effect of GnRH antagonists in FSH mildly stimulated intrauterine insemination cycles: a multicentre randomized trial

BACKGROUND: The usefulness of GnRH antagonists in mild controlled ovarian hyperstimulation (COH) and intrauterine insemination (IUI) cycles is debated. METHODS: Two-hundred and ninety-nine couples with unexplained or mild male factor infertility were enrolled in this international multicentre randomized controlled trial. Women allocated to the GnRH antagonist group (n=148) received 50 IU recombinant FSH starting on day 3 of the menstrual cycle and Ganirelix 0.25 mg daily starting from the day in which a follicle with a mean diameter of 13-14 mm was visualized at ultrasound. Women allocated to the control group (n=151) were administered only 50 IU recombinant FSH starting on day 3 of the menstrual cycle. Couples were recruited only for their first treatment cycle. The primary outcome was the clinical pregnancy rate per initiated cycle. RESULTS: Baseline characteristics of the two treatment groups were similar. Clinical pregnancy rates per initiated cycle in women who did and did not receive GnRH antagonists were 12.2 and 12.6%, respectively (P=1.00). The relative risk of conception (95% confidence interval) for the use of GnRH antagonists was 1.0 (0.5-1.9). CONCLUSIONS: In mild COH and IUI cycles, any benefit of the use of GnRH antagonists in improving pregnancy rates is <2-fold increase.     

Comparison of follicular fluid IGF-I, IGF-II, IGFBP-3, IGFBP-4 and PAPP-A concentrations and their ratios between GnRH agonist and GnRH antagonist protocols for controlled ovarian stimulation in IVF-embryo transfer patients

BACKGROUND: Insulin-like growth factors (IGF) and their binding proteins (IGFBP) play a major role in the autocrine and paracrine regulation of folliculogenesis. This is the first study that has compared follicular fluid (FF) IGF-I, IGF-II, IGFBP-3, IGFBP-4 and pregnancy-associated plasma protein (PAPP)-A concentrations, and their ratios, to investigate whether there was any difference in the intrafollicular microenvironment between the GnRH agonist (GnRHa) and antagonist (GnRHant) protocols for controlled ovarian stimulation (COS). METHODS: A total of 68 IVF cycles were included in this study; two groups were studied: GnRHa long protocol group (n = 36) and the flexible GnRHant multiple-dose protocol group (n = 32). FF was obtained from dominant follicles during oocyte retrieval and stored at -70 degrees C until assayed. IGF-I, IGF-II and IGFBP-3 concentrations were measured by radioimmunoassay and IGFBP-4 and PAPP-A by enzyme-linked immunosorbent assay. RESULTS: The duration of COS was significantly longer, and total dose of gonadotrophins used, serum estradiol (E(2)) levels on hCG day and the number of oocytes retrieved were significantly higher in the GnRHa long protocol group. The concentrations of FF IGF-II and IGFBP-4 were significantly higher, and the ratio of IGF-I/IGFBP-4 was significantly lower in the GnRHa long protocol group. Serum E(2) levels per mature follicle were not different between the two groups. CONCLUSIONS: Our data may indicate a difference of intrafollicular microenvironment between cycles using GnRHa long protocols and those using GnRHant protocols. However, the difference in microenvironment does not appear to result in a difference in clinical outcome.     

GnRH antagonists and mild ovarian stimulation for intrauterine insemination: a randomized study comparing different gonadotrophin dosages

BACKGROUND: The precise role of GnRH antagonists in the armamentarium of drugs for stimulation of ovulation associated with intrauterine insemination remains to be clarified. In this study, we have compared two different protocols employing GnRH antagonists in order to determine the lower effective dose of gonadotrophins to use. METHODS: Sixty-six couples with unexplained infertility or moderate male subfertility were recruited. Starting on day 3 of the cycle, 32 patients were randomized to receive 50 IU of recombinant FSH per day, whereas 34 were treated with 50 IU of recombinant FSH on alternate days. Women received the GnRH antagonist Ganirelix at a dose of 0.25 mg per day starting on the day in which a leading follicle > or =14 mm in mean diameter was visualized, until HCG administration. Insemination was performed 34 h after HCG injection. RESULTS: The regimen with daily recombinant FSH was associated with a lower rate of mono-ovulation (53.3% versus 78.8%, P=0.06) but also with a higher clinical pregnancy rate per initiated cycle (34.4% versus 5.9%, P=0.005). CONCLUSIONS: A protocol of recombinant FSH 50 IU daily and GnRH antagonist may represent an effective and safe regimen for ovulation induction associated with intrauterine insemination.     

Successful treatment of empty follicle syndrome by triggering endogenous LH surge using GnRH agonist in an antagonist down-regulated IVF cycle

To date, empty follicle syndrome (EFS) has only been reported in GnRH agonist down-regulated IVF cycles. Some cases have been successfully treated by changing the batch, or by repeating the dose of hCG. A case of EFS was observed in both GnRH antagonist and GnRH agonist down-regulated IVF cycles when final oocyte maturation was triggered using urinary hCG (u-hCG). Failure to retrieve oocytes occurred, despite administration of a further dose of u-hCG from a different batch and a delayed repeated oocyte recovery performed in the second GnRH agonist down-regulated cycle. A successful oocyte recovery cycle was achieved after triggering of an endogenous gonadotrophin surge using GnRH agonist in an antagonist down-regulated cycle. Nine oocytes were readily retrieved from 10 follicles, at 36 h after GnRH agonist administration, and eight of these fertilized normally. Two good quality embryos were used for fresh transfer and four were cryopreserved for future use. EFS can occur in GnRH antagonist down-regulated IVF cycles, and can be successfully treated by triggering a natural gonadotrophin surge using GnRH agonist in the absence of any response to previous treatment methods. This represents a novel therapeutic modality for this uncommon but frustrating condition.     

Direct ovarian effects and safety aspects of GnRH agonists and antagonists

In in-vitro fertilization programmes, gonadotrophin releasing hormone (GnRH) agonists are now routinely used in order to prevent the undesired pre-ovulatory spontaneous luteinizing hormone surge. The first publications are now appearing in which GnRH antagonists are used with the same purpose. More attention should be addressed to the safety aspects of these drugs. This review aims to summarize studies on direct ovarian effects of GnRH agonists and GnRH antagonists in non-primates and primates with respect to the functional and morphological aspects in-vitro as well as in-vivo. We conclude that there is a wide variety of functional and morphological effects of GnRH analogues on the ovary. The sometimes paradoxical effects indicate that a variety of factors may be involved in the various processes. Those factors are: (i) the type and dose of the analogue, (ii) the different regimens of administration, (iii) ovarian status at the time of exposure, (iv) ovarian cell types in in-vitro systems, (v) hormonal pre-treatment of these cultures, (vi) the type of hormonal stimulation added to the in-vitro culture, (vii) further methodological differences in the experiments and finally (viii) physiological variations in GnRH receptor abundance which depends on species and/or timing in the cycle. With the increasing number of patients using GnRH analogues in assisted reproduction treatments, there will be an increasing number of pregnancies exposed to these drugs. So far, there does not appear to be an increased risk of birth defects or pregnancy wastage in human pregnancies exposed to daily low-dose GnRH agonist therapy in the first weeks of gestation.     

GnRH agonist treatment in girls with precocious puberty does not compromise post-pubertal uterine size

BACKGROUND: Prompted by findings of a hypoestrogenic state in girls during prolonged treatment with GnRH agonist and a close association of estradiol serum concentrations with uterine volume in puberty, this study sought to evaluate uterine and ovarian size in girls with precocious puberty (PP) during and after treatment and the effect of age or duration of treatment. METHODS: Patients with idiopathic central PP before (n = 75), during (n = 41) or after (n = 30) treatment with GnRH agonist underwent transabdominal pelvic ultrasound examination. Findings were compared with those in 69 girls with epilepsy and no PP before initiation of anticonvulsant treatment. RESULTS: The girls with PP had significantly greater uterine and ovarian volumes before, during and after treatment with GnRH agonist than the controls, after adjusting for age at examination, weight, height and pubic and breast status. The average interval between the last treatment and the ultrasound examination was 1.3 years. There was no significant correlation between age at first treatment and uterine volume after treatment. Uterine volume decreased during treatment. There was a significant negative correlation between treatment duration and uterine volume after treatment (R(2) = -0.175, P = 0.024). Nevertheless, mean uterine volume was still greater in the treated group than in the control group (P = 0.002). CONCLUSION: The iatrogenic hypoestrogenic state in treated girls with PP does not compromise post-pubertal uterine size.     

A comparative randomized trial to assess the impact of oral contraceptive pretreatment on follicular growth and hormone profiles in GnRH antagonist-treated patients

BACKGROUND: This randomized controlled trial was designed to assess the impact of oral contraceptive (OC) scheduling with a GnRH antagonist (ganirelix) regimen on the ovarian response of women undergoing recombinant FSH (rFSH) stimulation for IVF, compared with a non-scheduled ganirelix regimen and a long GnRH agonist (nafarelin) protocol. METHODS: A total of 110 women was treated with an OC and ganirelix, 111 with ganirelix alone and 111 with nafarelin. The OC (containing 30 microg ethinylestradiol/150 microg desogestrel) was taken for 14-28 days and stopped 2 days prior to the start of rFSH treatment. Primary efficiency parameters were the number of cumulus-oocyte complexes (per attempt) and the number of grade 1 or 2 embryos (per attempt). RESULTS: In terms of follicular growth and hormone profiles, the OC-scheduled antagonist regimen mimicked the agonist regimen rather than the (non-scheduled) GnRH antagonist regimen. In the OC-scheduled GnRH antagonist group and the nafarelin group (versus the non-scheduled antagonist group), pituitary suppression was more profound at the start of stimulation (P < or = 0.001), there was a slower start of follicular growth (P < or = 0.001), longer stimulation was required (11.7 and 10.3 days respectively versus 9.4; P < or = 0.001), and more rFSH was used (2667 and 2222 IU versus 1966 IU; P < or = 0.001). In the three groups, the number of oocytes was similar (13.1, 12.9 and 11.5 respectively; not significant) as well as the number of good quality embryos (5.1, 5.7 and 5.0 respectively; not significant). CONCLUSION: OC treatment prior to the rFSH/ganirelix regimen can be successfully applied to schedule patients, although more days of stimulation and more rFSH are required than with a non-scheduled GnRH antagonist regimen.     

Initiation of GnRH antagonist on Day 1 of stimulation as compared to the long agonist protocol in PCOS patients. A randomized controlled trial: effect on hormonal levels and follicular development

BACKGROUND The optimal time for GnRH antagonist initiation is still debatable. The purpose of the current randomized controlled trial is to provide endocrine and follicular data during ovarian stimulation for IVF in patients with polycystic ovarian syndrome (PCOS) treated either with a long GnRH agonist scheme or a fixed day-1 GnRH antagonist protocol. METHODS Randomized patients in both groups (antagonist: n = 26; long agonist: n = 52) received oral contraceptive pill treatment for three weeks and a starting dose of 150 IU of follitropin beta. The primary outcome was E(2) level on Day 5 of stimulation, while secondary outcomes were follicular development, LH during ovarian stimulation and progesterone levels. RESULTS Significantly more follicles on days 5, 7 and 8 of stimulation, significantly higher estradiol (E(2)) levels on days 1, 3, 5, 7 and 8 and significantly higher progesterone levels on days 1, 5 and 8 of stimulation were observed in the antagonist when compared with the agonist group. E(2) was approximately twice as high in the antagonist when compared with the agonist group on day 5 of stimulation (432 versus 204 pg ml(-1), P lt; 0.001). These differences were accompanied by significantly lower LH levels on days 3 and 5 and significantly higher LH levels on days 1, 7 and 8 of stimulation in the antagonist when compared with the agonist group. CONCLUSIONS In PCOS patients undergoing IVF, initiation of GnRH antagonist concomitantly with recombinant FSH is associated with an earlier follicular growth and a different hormonal environment during the follicular phase when compared with the long agonist protocol.