比较GnRH拮抗剂与GnRHa短方案在卵巢低反应患者超促排卵中的应用

目的比较促性腺激素释放激素拮抗剂（GnRH-ant）方案与GnRHa短方案对卵巢低反应患者超促排卵行体外受精一胚胎移植（IVF-ET）结局的影响。方法72名卵巢低反应要求行IVF一ET治疗的患者,随机分为GnRH拮抗剂组共29个周期和GnRH激动剂短方案共43个周期。比较两组患者的周期取消率、Gn使用天数和剂量、获卵数、受精率、胚胎种植率、临床妊娠率。结果两组患者Gn使用天数和剂量、获卵数、受精率,胚胎种植率、临床妊娠率等比较均无显著统计学差异（P〉0.05）。GnRH拮抗剂组患者周期取消率、hCG日血清E2水平、LH水平显著低于GnRHa短方案组,差异有显著统计学意义（P〈O.05）。结论对卵巢低反应的患者促超排卵后行IVF-ET结局而言,GnRH拮抗剂方案并不优于GnRHa短方案,但为了减少周期取消率,可以考虑采用GnRH拮抗剂方案促排卵。     

GnRH拮抗剂在卵巢反应不良患者中的应用

目的探讨促性腺激素释放激素（GnRH）拮抗剂在卵巢反应不良患者中的应用。方法对既往应用体外受精-胚胎移植（IVF-ET）技术治疗过程中发生卵巢反应不良或取消周期的60例不孕患者随机对照分为两组,GnRH拮抗剂组和GnRH激动剂方案组,观察激素水平、获卵数、受精率、妊娠率等。结果拮抗剂组获卵数多于激动剂组（3.36±1.97 vs 2.43±0.92,P=0.038）,两组患者在HCG日LH水平、E2水平和P水平没有明显差异,在〉14mm的卵泡数、妊娠率分别为（3.04±1.33 vs 2.73±0.87,P=0.082）、（24%vs 14.3%,P=0.291）,两组患者均没有出现LH峰值。结论GnRH拮抗剂方案对卵巢反应不良的患者不失为可尝试的治疗方法。     

两种促排卵方案对高龄卵巢储备功能下降患者的疗效分析

目的比较促性腺激素释放激素激动剂(GnRHa)短方案与促性腺激素释放激素拮抗剂(GnRH-ant)方案对体外授精-胚胎移植(IVF-ET)高龄卵巢储备功能下降(DOR)患者的临床疗效。方法选择2014年1月-2016年6月在海南医学院附属医院生殖中心行IVF-ET的高龄DOR患者213个周期,其中采用短方案87个周期,拮抗剂方案126个周期。比较两组患者的一般资料、临床效果及结局(获卵数、2PN、MⅡ卵子数、可移植胚胎、优质胚胎数、周期取消率及临床妊娠率)。结果两组患者的一般资料无显著差异(P0.05)。两组的获卵数、2PN、MⅡ卵数、可移植胚胎、优质胚胎数、周期取消率及生化妊娠率均无显著差异(P0.05),但拮抗剂方案组临床妊娠率显著高于短方案组,差异具有统计学意义(P0.05)。结论对IVF-ET的高龄DOR患者,采用拮抗剂治疗方案的疗效优于短方案。     

改良超长降调节方案用于体外受精-胚胎移植卵巢低反应患者的临床研究

目的探讨改良超长降调节方案在既往体外受精一胚胎移植失败的卵巢低反应患者中的应用效果。方法回顾性分析本中心58例连续两周期行体外受精一胚胎移植术的卵巢低反应患者,其中第一周期采用拮抗剂方案,第二周期采用改良超长方案。自身对照比较两组临床及实验室结果。结果第二周期获得了38．2％的临床妊娠率,两组Gn启动剂量、HCG日E2、LH及P值、HCG日子宫内膜厚度、获卵数、移植胚胎数比较无统计学差异（P〉0．05）,可移植胚胎数、冷冻胚胎数第二周期均较第一周期高,但无统计学差异（P〉0．05）;Gn天数、优质胚胎率、周期取消率第二周期组较第一周期组高,均有统计学差异（P〈0．05）。结论对于既往采用拮抗剂方案失败的卵巢低反应患者,再次行体外受精-胚胎移植可尝试采用改良超长降调节方案。     

比较HMG、基因重组促卵泡素组合拮抗剂方案对卵巢低反应体外受精结局影响

目的探讨促性腺激素释放激素拮抗剂（GnRH拮抗剂）分别配伍HMG与基因重组促卵泡素方案对卵巢低反应患者控制性超排卵的效果,并比较两种不同组合对体外受精一胚胎移植结局是否存在差异。方法纳入研究对象为前次IVF—ET治疗失败,证明是卵巢低反应,要求再次IVF—ET治疗的患者,随机分为2组,A组使用GnRH拮抗剂＋HMG方案．共40周期,B组使用GnRH拮抗剂＋果纳芬,共40个周期。将两组患者的年龄、不孕年限、不孕类型、不孕原因、基础FSH水平、周期取消率、hCG日血清E2水平、LH水平、受精方式、自然流产率、临床妊娠率、胚胎种植率等进行比较。结果两组患者年龄、不孕年限、不孕类型、不孕原因、基础FSH水平、受精方式、周期取消率、自然流产率等比较差异均无显著性（P〉0．05）。两组患者的hCG日血清E2水平、LH水平、临床妊娠率、胚胎种植率等比较差异均有显著性（P〈0．05）,上述指标以GnRH拮抗剂＋HMG组为高。结论GnRH拮抗剂与HMG配伍,对卵巢低反应的患者是一种有效的超排卵治疗方案,与GnRH拮抗剂与基因重组促卵泡素组合相比,可以提高IVF—ET的临床妊娠率和胚胎种植率,并且费用低廉。     

预防OHSS行全胚冷冻的临床研究

目的探讨在辅助生育技术过程中出现卵巢过度刺激综合征(OHSS)倾向患者进行全胚冷冻,以预防OHSS发生,后进行冷冻胚胎移植的应用价值。方法选择2009年1月至2010年12月在本中心进行ART患者,共取卵1722周期,其中具有OHSS倾向患者201周期,占总取卵周期的11.67%,分极高危OHSS倾向组和高危OHSS倾向组两组。极高危OHSS倾向组给予全部胚胎冷冻,以后再安排冷冻胚胎移植,对于高危OHSS倾向组给予新鲜胚胎移植。比较促排卵药的使用总量及使用天数、HCG日E2水平、平均获卵数、平均胚胎数、平均优质胚胎数、OHSS发生率情况。比较全部胚胎冷冻进行复苏后移植与新鲜胚胎移植比较平均移植胚胎数、平均移植优质胚胎数、妊娠率、着床率、早期流产率等。结果1.两组患者的平均年龄、不孕年限、促排卵药的使用总量和天数无显著性差异;但全胚冷冻组HCG日E2水平、平均获卵数、平均胚胎数、平均优质胚胎数及OHSS发生率均高于新鲜周期移植组。2.全胚冷冻后行冷冻胚胎移植组与新鲜周期移植组的平均移植胚胎数、平均移植优质胚胎数、妊娠率、着床率、早期流产率均无显著性差异。结论 1.全胚冷冻不能减少早发型OHSS发生;2.为预防OHSS行全胎冷冻后,再行冷冻胚移植不影响不孕症患者治疗结局。     

卵泡期长效长方案与黄体期短效长方案在卵巢储备良好患者IVF-ET中的应用比较

目的比较卵泡期长效促性腺激素释放激素激动剂GnRH-a长方案和黄体期短效GnRH-a长方案在卵巢储备功能良好患者体外受精-胚胎移植中的治疗结局。方法回顾性分析2016年1月-2017年8月在我院行体外受精/卵胞浆内单精子注射-胚胎移植(IVF/ICSI-ET)的患者共320个周期,其中A组160周期(卵泡期长效长方案),B组160周期(黄体期短效长方案),比较两组患者的临床特征及妊娠结局。结果两组患者年龄,不孕年限,体重指数(BMI),基础窦卵泡数(AFC),基础卵泡刺激素(FSH),黄体生成素(LH),雌二醇(E2)无统计学差异(P0.05),A组促性腺激素(Gn)启动日,HCG注射日血LH值显著低于B组(P0.05),Gn使用天数,Gn总量,获卵数,胚胎种植率,临床妊娠率显著高于B组(P0.05),流产率,卵巢过度刺激综合征(OHSS)发生率无统计学差异(P0.05)。结论对于卵巢储备良好的患者,卵泡期长效长方案可显著提高获卵数,胚胎种植率及临床妊娠率,不增加流产率和OHSS发生率,是临床理想的治疗方案。     

Triptorelin和Buserelin对不孕妇女体外受精—胚胎移植疗效的比较

目的 比较GnRH-a制剂Triptorelin和Buserelin的体外受精—胚胎移植治疗效果.方法 185例不孕妇女随机分成两组,A组:85例,黄体期应用Triptorelin(月经第21d皮下一次性注射1.25～1.60mg);B组:100例,黄体期应用Buserelin.两组均用长方案降调节.比较两组的高纯度促卵泡刺激素用药剂量、取卵数、受精率、卵裂率和妊娠率.结果 两组的取卵数、受精率、卵裂率和妊娠率无显著性差异(P＞0.05).A组平均每周期用高纯度卵泡刺激素40.3±18.2支,B组平均每周期用30.2±12.3支,有显著性差异(P＜0.01).结论 Triptorelin和Buserelin的长方案均可获得高质量的成熟卵子,对不孕妇女的体外受精—胚胎移植治疗效果相似.Triptorelin的降调节作用较Buserelin的强.黄体期一次性皮下注射Triptorelin1.25～1.60mg可简化治疗过程,患者易于接受.     

不同剂量HCG对体外受精-胚胎移植中卵巢正常反应者妊娠结局的影响

目的研究不同剂量人绒毛膜促性腺激素(HCG)对体外受精-胚胎移植中卵巢正常反应患者卵子成熟及妊娠结局的影响。方法回顾性分析210个体外受精/卵胞浆内单精子注射-胚胎移植(IVF/ICSI-ET)周期,按肌注HCG剂量不同分为4000IU组,6000 IU组,10000IU组,统计观察3组患者获卵数,获卵率,成熟卵子率,受精率,临床妊娠率,流产率,卵巢过度刺激综合征(OHSS)发生率是否存在差异。结果 (1)3组患者年龄,不孕年限,体重指数,基础FSH,LH,E2,促性腺激素(Gn)总量,HCG日LH,HCG日E2差异均无统计学意义(P0.05)。(2)3组患者获卵数,获卵率,成熟卵子率,受精率,临床妊娠率,流产率,OHSS发生率差异均无统计学意义(P0.05),但HCG4000 IU组患者OHSS发生率有降低趋势。结论在卵巢正常反应患者中,适当减少HCG的注射剂量不影响卵子成熟及妊娠结局且OHSS发生率有降低趋势。     

不同胰岛素抵抗水平的多囊卵巢综合征患者体外受精-胚胎移植临床结果的分析

目的分析多囊卵巢综合征(PCOS)患者进行体外受精-胚胎移植(IVF-ET)时,其胰岛素抵抗水平与临床结果的关系。方法选择PCOS患者60例为实验组,月经周期规则的输卵管性不孕患者50例为对照组。PCOS组内,以稳态模型评价指数(HOMA-IR)的中位数(3.37)为标准,将PCOS患者分为高HOMA-IR组(30例)和低HOMA-IR组(30例)。三组患者均采用口服避孕药(OC)处理后的黄体期长方案进行体外受精-胚胎移植(IVF-ET),比较各组间体重指数、基础窦卵泡数、基础性激素水平、Gn的用量、获卵率、受精率、优质胚胎率、着床率、妊娠率、流产率及继续妊娠率与胰岛素抵抗水平的关系。结果三组患者获卵率、优质胚胎率、着床率和妊娠率差异均无统计学意义(P0.05)。PCOS组基础窦状卵泡数、获卵数多于对照组、Gn的用量少于对照组,受精率和继续妊娠率低于对照组,流产率高于对照组,差异有统计学意义(P0.05)。高HOMA-IR组基础窦状卵泡数多于低HOMA-IR组、Gn的用量少于低HOMA-IR组,受精率低于低HOMA-IR组,流产率高于低HOMA-IR组,继续妊娠率低于低HOMA-IR组,差异均有统计学意义(P0.05)。结论胰岛素抵抗水平是PCOS患者进行IVF-ET后妊娠结局产生的重要因素。     

Comparison of the GnRH agonist and antagonist protocol on the same patients in assisted reproduction during controlled ovarian stimulation cycles

Despite the fact that both gonadotropin-releasing hormone (GnRH) agonist and antagonist protocol are effective in suppressing the incidence of premature luteinizing hormone (LH) surges through reversibly blocking the secretion of pituitary gonadotropins, the exact impact of these two distinctive protocols on the clinical setting of patients for in vitro fertilization and embryo transfer (IVF-ET) treatment, however, remained controversial. We thus in the present report conducted a retrospective study to compare the impact of GnRH agonist and antagonist protocol on the same patients during controlled ovarian stimulation cycles. A total of 81 patients undergoing 105 agonist and 88 antagonist protocol were analyzed. We failed to detect a significant difference between two protocols for the difference in duration of ovarian stimulation, number of recombinant FSH (Gonal-F) ampoules used, number of oocytes retrieved, serum levels for estradiol (E2) and progestone (P), thickness of endometrium, and the zygote- and blastocyst-development rate. It is seemly that high quality embryo rate was higher in the antagonist protocol, but the data did not reach a statistical significance. Nevertheless, Implantation rate and clinical pregnancy rate were significantly higher in the antagonist protocol (10.64% and 30.26%, respectively) than that of the agonist protocol (5.26% and 15.82%, respectively). Our data also suggest that the GnRH antagonist protocol is likely to have the advantage for improving the outcome of pregnancy in those patients with a history of multiple failures for the IVF-ET treatment.     

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

The clinical application of gonadotrophin-releasing hormone (GnRH) antagonists instead of GnRH agonists, to prevent spontaneous premature luteinizing hormone surge during ovarian stimulation for assisted reproduction treatment has been advocated. A recent, double-blind, dose-finding study, including six dosages of the GnRH antagonist ganirelix, in women undergoing ovarian stimulation with recombinant follicle stimulating hormone (FSH), has indicated that high doses of GnRH antagonist (1 or 2 mg once daily) are associated with a low implantation rate. This follow-up study reports on the pregnancy rate after replacement of cryopreserved embryos obtained in stimulation cycles of the above-mentioned trial. Ovarian stimulation was initiated on day 2 of the cycle, with daily injections of 150 IU recombinant FSH. Ganirelix (0.0625, 0.125, 0.25, 0.5, 1.0 or 2.0 mg) was administered once daily from stimulation day 6 onwards, up to and including the day of human chorionic gonadotrophin. Retrieved oocytes were fertilized by in-vitro fertilization (IVF) or intracytoplasmic sperm injection and a maximum of three fresh embryos was transferred. Excess embryos were frozen, and subsequently used in either natural or programmed cycles. Until June 1998, 11 ongoing pregnancies (12-16 weeks after embryo transfer) were achieved from 46 cycles in which embryos had been first frozen (23.9% per transfer). Six of these 11 patients had been treated with a high dose of ganirelix (1.0 or 2.0 mg) during the IVF cycles in which the embryos were obtained. In conclusion, our data suggest that high dosages of ganirelix do not adversely affect the potential of embryos to establish clinical pregnancy in freeze-thaw cycles.     

Addition of GnRH antagonist in cycles of poor responders undergoing IVF

Concern about the use of gonadotrophin-releasing hormone (GnRH) agonists in ovarian stimulation of poor responder IVF patients has arisen from the claim that GnRH agonists might have a direct deleterious effect through their receptors on the ovary. In this study, we compared two ovarian stimulation protocols in which no GnRH agonists were used. In all, 40 patients with a poor response in previous treatment cycles were included. They were divided into two groups: group I (n = 20) received ovarian stimulation for 20 cycles, without the addition of either GnRH agonist or antagonist; while group II (n = 20) patients received ovarian stimulation for 20 cycles, including the administration of a GnRH antagonist (Cetrorelix, 0.25 mg daily) during the late follicular phase. There was no statistically significant difference between the groups for mean age, duration of infertility, baseline FSH concentration, cancellation rate, number of ampoules of gonadotrophin used, number of mature oocytes retrieved, oestradiol concentrations on the day of injection of human chorionic gonadotrophin (HCG), fertilization rate and number of embryos transferred. The clinical pregnancy and implantation rates in group II appeared higher than in group I, but were not significantly different (20 and 13.33% compared with 6.25 and 3.44% respectively). The addition of GnRH antagonists to ovarian stimulation protocols might be a new hope for poor responder IVF patients, but this report is preliminary and further controlled randomized prospective studies with larger sample sizes are required.     

Will GnRH antagonists provide new hope for patients considered 'difficult responders' to GnRH agonist protocols?

We have assessed the use of cetrorelix, a gonadotrophin releasing hormone (GnRH) antagonist, in conjunction with clomiphene citrate and gonadotrophin in 31 in-vitro fertilization (IVF)/gamete intra-Fallopian transfer (GIFT) cycles for 25 difficult responders. Group I included 18 poor responders (24 cycles) with no live birth in 23 previous IVF cycles with GnRH agonists. Group II included seven patients (seven cycles) with polycystic ovaries. Thirteen previous IVF/GIFT cycles with GnRH agonists had resulted in one live birth and three of these patients had developed ovarian hyperstimulation syndrome (OHSS). The treatment protocol involved a daily dose of clomiphene citrate 100 mg for 5 days and gonadotrophin injections from cycle day 2. Cetrorelix 0.25 mg/day was started when the leading follicle reached 14 mm. The outcome in both groups was favourable compared to previous treatment with GnRH agonists. In group I the abandoned cycle rate was 29 versus 57% (P = 0.06). More oocytes were produced (6.4 versus 4.7 oocytes/cycle) at a lower dose of follicle-stimulating hormone (FSH) (709 versus 1163 IU/oocyte; P = 0.08) and two live births resulted (11.8%). In group II fewer oocytes were produced (10.2 versus 14.5 oocytes/cycle), using a lower dose of gonadotrophin (170 versus 189 IU/oocyte) and resulted in one ongoing pregnancy. No patients experienced OHSS. This report is preliminary and a further controlled randomized study is required.     

Cessation of Gonadotropin-Releasing Hormone Antagonist on Triggering Day: An Alternative Method for Flexible Multiple-Dose Protocol

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

Modulation of the action of gonadotrophin surge-attenuating factor by gonadotrophin-releasing hormone

Gonadotrophin surge-attenuating factor (GnSAF) is a putativenon-steroidal ovarian factor which attenuates the luteinizinghormone (LH) surge in superovulated women through the reductionof the pituitary response to gonado-trophin-releasing hormone(GnRH). The mechanism of action of GnSAF on gonadotrophin secretionwas further studied by investigating six normally ovulatingwomen in two cycles a spontaneous and a follicle-stimulatinghormone (FSH)-treated cycle. The response of the pituitary tofive consecutive pulses of GnRH was investigated in late follicularphase (follicle size 15 mm) of both cycles. GnRH pulses, 10µg each, were injected i.v. every 2 h and LH was measuredin blood samples taken before and 30, 60 and 120 min after eachpulse. FSH was injected daily at the fixed dose of 225 IU startingon cycle day 2. Peak values of LH increment occurred 30 minafter each pulse. However, maximal LH increment occurred inboth cycles after the second GnRH dose. In the FSH cycles theresponse of LH to the first three pulses was significantly attenuatedcompared with the spontaneous cycles, while the response tothe fourth and fifth pulses was similar in the two cycles. Inboth cycles, LH increment 30 min post GnRH (net increase abovethe previous value) was similar after the fourth and fifth pulses.Serum concentrations of oestradiol and immunoreactive inhibin,although higher in the FSH cycles, remained stable throughoutthe GnRH experimental period in both cycles. These results demonstratethat multiple submaximal doses of GnRH can override the attenuatingeffect of GnSAF on LH secretion. From a physiological pointof view, this is possibly part of the mechanism which controlsthe action of GnSAF at mid-cycle.     

Clinical management of low ovarian response to stimulation for IVF: a systematic review

Poor response is not a rare occurrence in ovarian stimulation. Although not fully accepted, the most dominant criteria for poor ovarian response are small numbers of follicles developed or oocytes retrieved, and low estradiol (E2) levels after the use of a standard stimulation protocol. There is no ideal predictive test as the poor responder is revealed only during ovulation induction; however, increased levels of day 3 FSH and E2 as well as decreased levels of inhibin B can be used to assess ovarian reserve. Several protocols have been proposed for clinical management of low ovarian response in IVF. Although high doses of gonadotrophins have been used by the vast majority of authors, results have been controversial and prospective randomized studies have shown little or no benefit. The few available relevant studies do not indicate that recombinant FSH improves outcome. Flare-up GnRH agonist protocols (including all dosage varieties) produce better results than standard long luteal protocols. Luteal initiation GnRH agonist 'stop' protocols were shown to improve ovarian response according to prospective studies with historical controls, but this was not confirmed by well-designed prospective, randomized, controlled studies. The few available data obtained with GnRH antagonists have not shown any benefits. Adjuvant therapy with growth hormone (GH) or GH-releasing factors results in no significant improvement. The use of corticosteroids reduces the incidence of poor ovarian response in women undergoing IVF treatment. The limited data obtained with nitric oxide donors are encouraging. Pretreatment with combined oral contraceptives prior to stimulation may help ovarian response. No benefit was observed with standard use of ICSI or assisted hatching of zona pellucida. Finally, natural cycle IVF has produced results which are comparable with those obtained with stimulated cycles in true poor responders. Well-designed, large-scale, randomized, controlled trials are needed to assess the efficacy of these different management strategies.     

Induction of the endogenous gonadotrophin surge for oocyte maturation with intra-nasal gonadotrophin-releasing hormone analogue (buserelin): effective minimal dose

From 1985-1987, a total of 34 couples undergoing superovulation for a single in-vitro fertilization (IVF) cycle with clomiphene citrate and purified follicle stimulating hormone (FSH) or human menopausal gonadotrophin (HMG) were randomly allocated doses of intra-nasal buserelin to induce an endogenous gonadotrophin surge, prior to oocyte collection. The doses ranged from a single 25 microg dose to 100 microg every 4 h for 20 h. In three cycles the treatment was abandoned because of a poor ovarian response. In the remaining 31 cycles buserelin was given to induce the endogenous gonadotrophin surge, but there was evidence of premature luteinization in eight cycles and a premature gonadotrophin surge in four cycles. Although a single dose as low as 40 microg induced a surge and resulted in a pregnancy, a single dose of 50 microg proved the most effective minimal dose consistently to induce a gonadotrophin surge and oocyte maturation. Recent reports using gonadotrophin-releasing hormone (GnRH) analogues to induce a gonadotrophin surge has prompted publication of this previously unpublished data.      

The use of GnRH antagonists in ovarian stimulation

GnRH antagonists induce a rapid decrease in LH and FSH, preventing and interrupting LH surges. Their properties do not require a desensitization period, and this allows their use in the late follicular phase. GnRH antagonists could replace GnRH agonists in controlled ovarian stimulation without their side-effects and their long desensitization period. Two protocols for assisted reproduction technology (ART) cycles were designed: the single-dose protocol allies simplicity and efficacy, while the multiple-dose protocol is efficient and could reduce monitoring of the cycle, though compliance is mandatory. A review of the available literature on GnRH antagonists in ART cycles is presented, focusing on phase III controlled trials and ART results. Both protocols using GnRH antagonists were associated with the need for a smaller dose of gonadotrophin, a shorter stimulation period and a lower incidence of ovarian hyperstimulation syndrome (OHSS), albeit with statistically comparable pregnancy rates. A trend is observed in all studies showing a lower pregnancy rates in GnRH antagonist cycles as compared with GnRH agonist cycles. The role of the lower number of embryos, and the potential adverse effects of GnRH antagonists on endometrium or follicle must be studied. More cycles using GnRH antagonists are necessary to confirm their equivalent pregnancy rates. There is room for improvement in both protocols with regard to scheduling, antagonist dose level and the timing of its administration. Until further studies have been conducted, luteal support seems to remain mandatory. Perinatal outcome appears similar to that with other stimulation regimens. Triggering of ovulation can be obtained with GnRH agonist for patients at risk of OHSS. With regard to GnRH antagonists, questions remain regarding pregnancy rates, the indications of their use in patients with polycystic ovary syndrome or poor responders, and in ovarian stimulation outside IVF.