AOGS COMMENTARY SHAHAR KOL 1, ROY HOMBURG 2,3, BIRGIT ALSBJERG 4 & PETER HUMAIDAN 5. Abstract

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A C TA Obstetricia et Gynecologica AOGS COMMENTARY The gonadotropin-releasing hormone antagonist protocol the protocol of choice for the polycystic ovary syndrome patient undergoing controlled ovarian stimulation SHAHAR KOL 1, ROY HOMBURG 2,3, BIRGIT ALSBJERG 4 & PETER HUMAIDAN 5 1 Department of Obstetrics and Gynecology, IVF Unit, Rambam Medical Center, Haifa, Israel, 2 Barzilai Medical Center, Ashkelon, Israel, 3 Homerton University Hospital, London, UK, 4 The Fertility Clinic, Skive Regional Hospital, Skive, Denmark and 5 The Fertility Clinic, Department D, Odense University Hospital, Odense, Denmark Key words Polycystic ovary syndrome, ovarian hyperstimulation syndrome, gonadotropin-releasing hormone agonist, gonadotropin-releasing hormone antagonist, in vitro fertilization, controlled ovarian stimulation Correspondence Peter Humaidan, The Fertility Clinic, Department D, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark. E-mail: peter.humaidan@ouh.regionsyddanmark.dk Conflict of interest The authors have stated explicitly that there are no conflicts of interest in connection with this article. Please cite this article as: Kol S, Homburg R, Alsbjerg B, Humaidan P. The gonadotropinreleasing hormone antagonist protocol the protocol of choice for the polycystic ovary syndrome patient undergoing controlled ovarian stimulation. Acta Obstet Gynecol Scand 2012; 91:643 647. Abstract Polycystic ovary syndrome (PCOS) patients are prone to develop ovarian hyperstimulation syndrome (OHSS), a condition which can be minimized or completely eliminated by the use of a gonadotropin-releasing hormone agonist (GnRHa) trigger. In this commentary paper, we maintain that the gonadotropin-releasing hormone antagonist protocol should be the protocol of choice for the PCOS patient undergoing ovarian stimulation with gonadotropins for in vitro fertilization. If an excessive ovarian response is encountered, the clinician will always have two options: either to trigger final oocyte maturation with a bolus of GnRHa and supplement the luteal phase with a small bolus of human chorionic gonadotropin in addition to the standard luteal phase support and transfer in the fresh cycle or, alternatively, to trigger with GnRHa and perform a total freeze, resulting in a complete elimination of OHSS and high ongoing pregnancy rates in the subsequent frozen thawed transfer cycles. Abbreviations: GnRH, gonadotropin-releasing hormone; GnRHa, gonadotropinreleasing hormone agonist; hcg, human chorionic gonadotropin; IVF, in vitro fertilization; LH, luteinizing hormone; OHSS, ovarian hyperstimulation syndrome; PCOS, polycystic ovary syndrome; RCT, randomized controlled trial. Received: 19 December 2011 Accepted: 5 March 2012 DOI: 10.1111/j.1600-0412.2012.01399.x Following its introduction at the turn of the millennium, the gonadotropin-releasing hormone (GnRH) antagonist protocol has been used successfully in assisted reproductive technology. Although, previously, it was debated whether or not the long GnRH agonist (GnRHa) protocol was superior to the GnRH antagonist protocol in terms of the reproductive outcome (1,2), the latest meta-analysis showed no difference in the live birth rate between the two GnRH analogs (3). Moreover, the GnRH antagonist protocol is associated with a significant reduction in the occurrence of ovarian hyperstimulation syndrome (OHSS; 3,4). Importantly, GnRH antagonist cotreatment allows final oocyte maturation to be triggered with a bolus of GnRHa instead of human chorionic gonadotropin (hcg; 5); a procedure which is known to either totally eliminate or significantly reduce the risk of OHSS in the high-risk patient. Thus, of 2034 patients Acta Obstetricia et Gynecologica Scandinavica C 2012 Nordic Federation of Societies of Obstetrics and Gynecology 91 (2012) 643 647 643

Gonadotropin-releasing hormone antagonist protocol S. Kol et al. Table 1. Main characteristics and OHSS rate in studies on GnRHa triggering vs. hcg triggering of final oocyte maturation. Reference Trial type Oocyte source Ovulation trigger n Cumulus oocyte complex (mean) OHSS risk OHSS [% (n)] Acevedo et al. (2006) RCT Donors GnRHa 30 9.1 Low 0 (0/30) hcg 30 10.3 Low 17 (5/30) Babayof et al. (2006) RCT Own GnRHa 15 19.8 High 0 (0/13) hcg 13 19.5 High 31 (4/13) Engmann et al. (2006) Retrospective Own GnRHa 23 20 High 0 (0/23) hcg 23 18 High 4 (1/23) Orvieto et al. (2006) Retrospective Own GnRHa 82 22.3 High 0 (0/82) hcg 69 16.8 High 7 (5/69) Griesinger et al. (2007) Observational Own GnRHa 20 16.4 High 0 (0/20) Shapiro et al. (2007) Retrospective Donors GnRHa 32 28.8 High 0 (0/32) hcg 42 21.7 High 1 (1/42) Engamnn et al. (2008) RCT Own GnRHa 33 20.2 High 0 (0/33) hcg 32 18.8 High 31 (10/32) Bodri et al. (2009) Retrospective Donors GnRHa 1046 13.6 Intermediate 0 (0/1046) hcg 1031 9.8 Low 1.3 (13/1031) Humaidan et al. (2009) RCT Own GnRHa 152 8.9 Low 0 (0/152) hcg 150 9.3 Low 2 (3/150) Hernandez et al. (2009) Retrospective Donors GnRHa 254 13.2 Intermediate 0 (0/254) hcg 175 8.7 Low 6 (10/175) Melo et al. (2009) RCT Donors GnRHa 50 17.1 High 0 (0/50) hcg 50 18.1 High 4 (2/50) Sismanoglu et al. (2009) RCT Donors GnRHa 44 38.2 Very high 0 (0/44) hcg 44 36.7 Very high 7 (3/44) Humaidan et al. (2009) Observational proof of concept Own GnRH, luteal rescue with hcg (1500 IU) 12 21.5 High 8 (1/12) Galindo et al. (2009) RCT Donors GnRHa 106 11.4 Low 0 (0/106) hcg 106 12 Low 8 (9/106) Manzanares et al. (2010) Retrospective Own GnRHa 42 12.6 High 0 (0/42) case control hcg cancelled Tehraninejad et al. (2010) RCT, high risk Own GnRHa 45 13.4 High 0 (0/45) hcg 45 10.9 High 15 (33) Griesinger et al. (2010) Prospective cohort study Own GnRHa 40 18 High 0 (0/40) Abbreviations: GnRH, gonadotropin-releasing hormone; GnRHa, gonadotropin-releasing hormone agonist; hcg, human chorionic gonadotropin; OHSS, ovarian hyperstimulation syndrome; PCOS, polycystic ovary syndrome; and RCT, randomized controlled trial. 644 Acta Obstetricia et Gynecologica Scandinavica C 2012 Nordic Federation of Societies of Obstetrics and Gynecology 91 (2012) 643 647

S. Kol et al. Gonadotropin-releasing hormone antagonist protocol triggered with a GnRHa in published studies only one patient developed mild OHSS (after hcg rescue), whereas 83 of 1810 patients triggered with hcg (4.6%) developed OHSS (Table 1). In the era of personalized treatment, clinicians are obliged to consider each individual patient prior to stimulation to determine the most appropriate protocol, combining the lowest treatment burden and risk with the highest chance of conception. Thus, for the oocyte donor it is now generally recommended that ovarian stimulation should be performed with GnRH antagonist cotreatment, while final oocyte maturation should be accomplished with a bolus of GnRHa instead of hcg, because this protocol eliminates OHSS and gives less discomfort for the donor in the luteal phase, i.e. the days following oocyte aspiration, as well as an excellent reproductive outcome in the recipient (6 10). Regarding the polycystic ovary syndrome (PCOS) patient, a meta-analysis including four randomized controlled trials (RCTs), comparing the two GnRH analogs in 305 PCOS patients, reported no difference in the reproductive outcome (11), a finding which has been corroborated by others (12 14). As previously mentioned, the main advantages of GnRH antagonist cotreatment are a significant reduction in the risk of OHSS as well as the possibility of using a GnRHa trigger for final oocyte maturation (15). The total OHSS incidence (mild, moderate and severe) in a high-risk population, mainly consisting of PCOS patients, undergoing ovarian stimulation for in vitro fertilization (IVF) after either a long pituitary suppression with Gn- RHa or cotreatment with a GnRH antagonist and having final oocyte maturation triggered with hcg has been reported to be as high as 17 31% (16,17), whereas the incidence of severe OHSS has been reported to be 15% in the PCOS IVF patient (18). This number should be compared with the general IVF population, in which the incidence of moderate OHSS has been described to be 5% and the severe cases in need of hospitalization 2% (19). Regardign the concept of a GnRHa trigger and the subsequent reproductive outcome, the results of the first RCT in normogonadotropic patients revealed an extremely high early pregnancy loss rate (80%) despite a standard luteal phase support (20). The finding was interpreted as a luteal phase insufficiency caused by low circulating endogenous luteinizing hormone (LH) levels in the early to mid-luteal phase (21 23), and during the following years, focus was directed towards rescuing the luteal phase, by an increase in the luteal LH activity after the initial GnRHa trigger with hcg, recombinant LH or repeated boluses of GnRHa; socalled modified luteal phase support after GnRHa trigger. In the normogonadotropic as well as the OHSS high-risk patient, this intervention has resulted in a reproductive outcome comparable to that seen after hcg triggering (21 27). Thus, although a recent meta-analysis on earlier studies using a GnRHa trigger did not recommend the use of GnRHa trigger in fresh cycles owing to an expected lower birth rate (28), we maintain that this statement was too premature, because the newer studies, using the modified luteal phase support, were not included in the analysis. This issue was thoroughly addressed in a recent debate regarding the performance of meta-analyses during the development of new concepts (29). Regarding OHSS high-risk patients, who are mainly PCOS patients, different approaches for luteal phase rescue have been suggested after GnRHa trigger. Humaidan (22), in a proof-of-concept study including 12 OHSS high-risk patients ( 25 follicles on day of trigger), rescued the luteal phase with a combination of a bolus of 1500 IU hcg on the day of oocyte retrieval (21) and conventional luteal phase support consisting of vaginal progesterone and estradiol; so-called modified luteal phase support. This modified approach after the GnRHa trigger resulted in a live birth rate of 50%. One patient developed moderate late-onset OHSS, and the patient was treated on an outpatient basis. RadesicandTremellen(27),inaretrospectivestudy,analysed 71 consecutive OHSS high-risk patients who had been treated according to the protocol suggested by Humaidan et al. (21 23). Forty-five per cent of the patients were PCOS patients, and the mean anti-müllerian hormone level of patients was 48 pmol/l. A high risk of developing OHSS was defined as the presence of at least 14 follicles 12 mm on the day of triggering final oocyte maturation. All patients were triggered with a bolus of GnRHa (leuprolide acetate, 2 mg), followed by 1500 IU hcg administered subcutaneously, after the oocyte retrieval. A mean of 17 oocytes were retrieved, andall71patientsreceivedasingleembryotransfer.this resulted in a clinical pregnancy rate of 52% per transfer and a miscarriage rate of 8%. One patient (one of 71) developed a late-onset severe OHSS, requiring hospital admission on day 16 post-oocyte retrieval. The patient was treated according to guidelines for severe OHSS and was discharged 7 days later. Likewise, Shapiro et al. (30) retrospectively reported the effect of a so-called dual trigger in OHSS high-risk patients, mainly patients with a polycystic ovary-like ultrasonography pattern and PCOS patients. A total of 182 patients were treated according to this protocol, receiving on the day of triggering final oocyte maturation 4 mg leuprolide acetate as well as a mean of 1428 IU hcg as a trigger. Patients had a mean of 28 follicles on the day of triggering, and a mean of 20 oocytes were retrieved. After blastocyst transfer, an ongoing pregnancy rate of 58% per transfer was obtained. One patient (one of 182) in this high-risk group of patients developed a late onset OHSS. Taken together, the optimal protocol for luteal phase supportaftergnrhatriggeriscurrentlyunderinvestigation and still needs to be fine-tuned. The protocol developed Acta Obstetricia et Gynecologica Scandinavica C 2012 Nordic Federation of Societies of Obstetrics and Gynecology 91 (2012) 643 647 645

Gonadotropin-releasing hormone antagonist protocol S. Kol et al. by Humaidan et al. (21,23) of administration of a bolus of 1500 IU hcg immediately after the oocyte pick-up, followed by a standard luteal phase support with 4 mg estradiol and vaginal progesterone has been shown to result in live birth rates comparable to those seen after hcg triggering in both normogonadotropic patients and PCOS patients (21 23,27). An alternative solution in patients at high risk of OHSS is to freeze all embryos after GnRHa triggering, and transfer in subsequent either natural or substituted freeze thaw cycles. No incidence of OHSS was reported, and a high cumulative pregnancy rate was seen following this procedure in IVF patients (10,31). Moreover, in several thousand oocyte donation patients triggered with GnRHa, some of whom were at high risk of developing OHSS, not a single OHSS case was recorded (6,8,32) Thus, this simple medical intervention after ovarian stimulation seems to eliminate OHSS and thus provides the clinician with a good alternative to a fresh transfer, provided that the clinic has a good cryopreservation program. Patient-friendly IVF is a repeated theme in the field of assisted reproductive technology and is a driving force for the development of new stimulation protocols. In this context, it should be emphasized that the GnRHa trigger is associated with a significantly lower mid-luteal ovarian volume (17), which is directly correlated with patient comfort, even if an OHSS condition does not develop. Thus, in oocyte donors triggered with hcg, 42% reported subjective complaints (mostly abdominal discomfort), whereas this percentage was 0% in those who received GnRHa to trigger ovulation (33). Therefore, we propose that even if OHSS is not an immediate threat, GnRHa should be considered for the triggering of final oocyte maturation in the PCOS patient, simply in the interest of patient comfort. In conclusion, based on the results of current clinical research, we maintain that GnRH antagonist cotreatment should be recommended instead of the long GnRHa protocol when stimulating PCOS patients for IVF. If an extreme response is encountered, the clinician will always have the option of triggering final oocyte maturation with GnRHa, followed by either a modified luteal phase support or a total freeze of embryos and transfer in subsequent thaw cycles. Both approaches will ensure a good reproductive and clinical outcome, with very little or no risk at all of OHSS development. References 1. Al-Inany HG, Abou-Setta AM, Aboulghar M. Gonadotrophin-releasing hormone antagonists for assisted conception: a Cochrane review. Reprod Biomed Online. 2007;14:640 9. 2. 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