Correlation of IL-1, IL-6, IL-10 Concentrations to Ovarian Hyperstimulation Syndrome and Effect of Intravenous Immunoglobulin on Ovarian Hyperstimulated Rats

Objective To investigate the correlation of interleukin（IL）-1,IL-6 and IL-10 concentrations to ovarian hyperstimulation syndrome（OHSS） and whether intravenous immunoglobulin（IVIG） has the effects on ovarian hyperstimulated rats. Methods Immature female Wistar rats were divided into control group, OHSS group （n=13） and IVIG group（n=13）. For the latter two groups, pregnancy mare serum gonadotropin（PMSG）and human chorionic gonadotropin（hCG） were given to induce OHSS, and rats in IVIG group were treated with immunoglobulin. Forty-eight hours after administration of hCG, capillary permeability was evaluated from the Evans blue dye（EB） concentration in the ovaries and the EB concentration in peritoneal irrigated fluid at 30 min after the intravenous injection of EB. Rats＇ blood samples and ovaries were obtained to be measured for IL-1, IL-6 and IL-10 by ELISA. Results In OHSS group, total weights of bilateral ovaries and the ovarian EB concentration were significantly higher than those in others（P〈0.05）. Both serum and ovarian concentrations of IL-1 were significantly higher in OHSS and IVIG groups than those in control group （P〈0.05）. The ovarian concentrations of IL-6 and IL-10 in IVIG group were significantly lower than those in control group（P〈0.05）. Furthermore, the ovarian IL-10 concentration in IVIG group was significantly lower than that in OHSS group（P〈0. 05）. Conclusion Inflammation involved IL-1 in OHSS rats plays an important role. Vascular permeability was mostly increased in ovaries of hyperstimulated rats. It appears that ovaries of OHSS rats may be the primary places of inflammation. IVIG treatment resulted in statistically significant reductions in ovaries＇ weights and ovarian vascular permeability of OHSS rats, with a decreased level of ovarian IL-10. It implys that IVIG have a beneficial effect in reducing the severity of OHSS in the experimental model maybe by restrainning IL-10.

Spontaneous ovarian hyperstimulation syndrome: Report of two cases

BACKGROUND Spontaneous ovarian hyperstimulation syndrome(s OHSS) is extremely rare. It can be divided into four types according to its clinical manifestations and follicle stimulating hormone receptor mutations.CASE SUMMARY Here we report two cases of s OHSS in Chinese women, one with a singleton gestation developing s OHSS in the first trimester who conceived naturally and the other with a twin pregnancy developing s OHSS in the second trimester after a thawed embryo transfer cycle. Both patients were admitted to the hospital with abdominal distension, ascites, and enlarged ovaries. Conservative treatment was the primary option of management. The first patient had spontaneous onset labor at 40 wk of gestation and underwent an uncomplicated vaginal delivery of a male newborn. The second patient delivered a female baby and a male baby by caesarean section at 35 wk and 1 d of gestation.CONCLUSION Patients with a history of ovarian hyperstimulation syndrome should be closely monitored. Single embryo transfer might reduce the risk of this rare syndrome.

Ovarian hyperstimulation syndrome following the use of GnRH agonist trigger of final oocyte maturation and freeze-all strategy: A case report and review of the literature

Rationale:The current literature has a surprising controversy regarding the use of low-dose human chorionic gonadotropin(hCG)for luteal support as an explanation for the development of ovarian hyperstimulation syndrome,and this is because of the gap in the listing of the predisposing factors that put women at an increased risk of ovarian hyperstimulation syndrome.Patient concerns:A case of 25-year-old woman presented with abdominal pain,distention,dyspnea,and nausea with a 6.5 kg increase in weight from baseline.Ultrasonographic examination showed bilaterally enlarged multicystic ovaries after gonadotropin-releasing hormone(GnRH)agonist triggering and cycle segmentation with no hCG rescue administration.Diagnosis:Moderate/severe ovarian hyperstimulation syndrome.Interventions:The woman was admitted to the hospital for medical management of moderate/severe ovarian hyperstimulation syndrome,and pain management was advanced to patient-controlled anesthesia with the start of low molecular weight heparin.On day 2,albumin therapy followed by a furosemide chase was started due to an increase in abdominal girth.On day 1,Cabergoline was maintained,and on day 2 the GnRH antagonist Cetrorelix was started.Outcomes:The woman’s clinical condition improved,and a clinical pregnancy was eventually achieved during the first cryo-warmed blastocyst cycle.Lessons:Ovarian hyperstimulation syndrome can still happen even after the use of GnRH agonist and avoidance of hCG support.Segmentation of in vitro fertilization with complete avoidance of hCG for luteal support remains the best approach.

Common carotid artery thrombosis and malignant middle cerebral artery infarction following ovarian hyperstimulation syndrome:A case report

BACKGROUND Arterial thrombosis is a serious and rare complication of ovarian hyperstimulation syndrome(OHSS).Herein,we describe a case of OHSS complicated by common carotid artery thrombosis and malignant middle cerebral artery infarction after egg retrieval and before embryo transfer.CASE SUMMARY A 32-year-old female with a family history of thrombosis who was undergoing in vitro fertilization due to unexplained infertility,was admitted due to abdominal distension for 3 d and coma for 2 h.She received egg retrieval 7 d ago and embryo transfer had not yet been performed.Blood biochemical analysis showed estrogen of 15781 pmol/L.Gynecological examination showed palpable masses on both sides of the adnexal areas.Ultrasound observed enlarged ovaries and abdominal ascites.Imaging examination of the head and neck revealed fresh malignant middle cerebral artery infarction in the left side of brain and internal carotid artery as well as occlusion in the left carotid artery,internal carotid artery,and middle cerebral artery.The patient was finally diagnosed with severe OHSS,complicated by common carotid artery thrombosis and malignant middle cerebral artery infarction.Liquid replacement,anticoagulation,vascular endothelium protection,brain protection and decompressive craniectomy were carried out.Rehabilitation training was then performed for 6 mo.At present,she has poor speaking ability and decreased muscle strength on the right side.CONCLUSION There is a risk of thrombosis during any period of OHSS.During in vitro assisted reproduction,for cases with a family history of thrombosis,hyperlipidemia and other high-risk factors,serum lipid levels should be controlled as soon as possible to improve metabolic dysfunction.When thrombosis occurs,timely and effective treatment should be performed to improve the prognosis.

Peripheral blood transcriptome analysis of patients with ovarian hyperstimulation syndrome through high-throughput sequencing

Objective:Ovarian hyperstimulation syndrome(OHSS)is a frequent iatrogenic complication that arises during assisted reproduction and accounts for approximately 30%of all in vitro fertilization cycles.Using high-throughput sequencing,we investigated the peripheral blood transcriptome of patients with OHSS.Methods:Peripheral blood samples were obtained from 15 patients in each of the OHSS high-risk and low-risk groups on the ovum pick-up day.Subsequently,high-throughput sequencing was used to obtain the peripheral blood transcriptomes of five patients each from the high-and low-risk groups.Bioinformatic tools were used for mRNA expression profile mapping and screening of differentially expressed genes(DEGs).Bioinformatics techniques were also implemented in the Kyoto Encyclopedia of Genes Genomes(KEGG)signal pathway,Gene Ontology(GO)function,and protein-protein interaction(PPI)network analyses of DEGs.Results:A total of 20,031 genes were identified and 148 were found to be differentially expressed(P<0.05,|log_(2)FC|>0.58),with 52 upregulated and 96 downregulated genes.GO and KEGG analyses indicated that these genes were involved in extracellular corpuscles(GO:0070062),plasma membrane(GO:0005886),extracellular regions(GO:0005576),immune system response(GO:0006955),PI3K-Akt signaling pathways(hsa04151),cell adhesion molecules(CAMs,hsa04514),focal adhesion(hsa04510),and complement and coagulation cascades(hsa04610).The PPI network and realtime fluorescence quantitative polymerase chain reaction(qPCR)verification predicted that complement C3,von Willebrand factor,and vascular cell adhesion protein 1 proteins are highly implicated in OHSS and may serve as potential biomarkers for future OHSS studies.Conclusion:Transcriptome analysis revealed several DEGs related to OHSS risk factors in the peripheral blood,indicating that these DEGs may be novel players in OHSS development.

Pregnancy Outcomes of In Vitro Fertilization with or without Ovarian Hyperstimulation Syndrome： A Retrospective Cohort Study in Chinese Patients

Background： The effect of ovarian hyperstimulation syndrome （OH SS） on pregnancy outcomes of in vitro fertilization （IVF） patients is still ambiguous. Tbis study aimed to analyze pregnancy outcomes of IVF with or without OHSS in Chinese patients. Methods： A retrospective cohort study was undertaken to compare pregnancy outcomes between 190 women with OHSS and 197 women without OHSS. We examined the rates of clinical pregnancy, multiple pregnancies, miscarriage, live birth, preterm deliver）,, preterm birth before 34 weeks＇ gestation, cesarean delivery, low birth weight （LBW）, and small-for-gestational age （SGA） between the two groups. Odds ratios （ORs） and 95% confidence intervals （Cls） of measure of clinical pregnancy were also analyzed. Results： The clinical pregnancy rate of OHSS patients was significantly higher than that of non-OHSS patients （91.8% vs. 43.5%, P 〈 0.001）. After controlling for drug protocol and causes of infertility, the adjusted ORs of moderate OHSS and severe/critical OHSS for clinical pregnancy were 4.65 （95% CI, 1.86-11.61 ） and 5.83 （95% CI, 3.45-9.86）, respectively. There were no significant differences in rates of muhiple pregnancy （4.0% vs. 3.7%） and miscarriage （16.1% vs. 17.5%） between the two groups. With regard to ongoing clinical pregnancy, we also found no significant differences in the rates of live birth （82.1% vs. 78.8%）, preterm delivery （20.9% vs. 17.5%）, preterm birth before 34 weeks＇ gestation （8.6% vs. 7.9%）, cesarean delivery （84.9% vs. 66.3%）, LBW （30.2% vs. 23.5%）, and SGA （21.9% vs. 17.6%） between the two groups. Conclusion： OHSS, which occurs in the luteal phase or early pregnancy in IVF patients and represents abnormal transient hemodynamics, does not exert any obviously adverse effect on the subsequent pregnancy.

Effects of gonadotropin-releasing hormone antagonists on the expression of vascular endothelial growth factor and its receptors in a rat model of ovarian hyperstimulation syndrome

Background Ovarian hyperstimulation syndrome （OHSS） is one of the most life-threatening complications of assisted reproduction treatments. Gonadotropin-releasing hormone antagonists （GnRHanta） are thought to be effective in preventing this complication, and some clinical trials have found lower incidences of OHSS in patients treated with GnRHanta. Our aim was to investigate the effects of GnRHanta on vascular permeability and the expression of vascular endothelial growth factor （VEGF） and its receptors in a rat model of OHSS. Methods An immature early OHSS rat model was established. Three ovarian stimulation protocols were used： pregnant mare serum gonadotropin/human chorionic gonadotropin （hCG） alone, with a GnRHanta, or with a gonadotropin-releasing hormone agonists （GnRHa）. Blood and tissue samples were collected at 48 hours after hCG administration. Vascular permeability was evaluated by measuring the Evans-Blue content of extravasated peritoneal fluids. The expression of VEGF and its receptors, including fit-1 and KDR, were detected by reverse transcriptase-polymerase chain reaction and Western blotting. Results Treatment with both a GnRHanta and a GnRHa resulted in significant reductions in serum estradiol and peritoneal vascular permeability, as well as decreased ovarian expression of VEGF and its two receptors. However, GnRHanta treatment caused a greater reduction in serum estradiol concentrations, and in VEGF receptor mRNA expression than GnRHa. There were no significant reductions in the expression of VEGF or its receptors in extra-ovarian tissues, including the liver, lungs and peritoneum. Conclusion Our results reveal that GnRHanta are more potent than GnRHa in preventing early OHSS through down-regulation of the expression of VEGF and its receptors in hyperstimulated ovaries.

Predictive Value of Serum Vascular Endothelial Growth Factor and Pigment Epithelium-derived Factor in Ovarian Hyperstimulation Syndrome

Objective To explore whether the serum concentrations of vascular endothelial growth factor （VEGF） and pigment epithelium-derived factor （PEDF） could serve as the predictors of ovarian hyperstimulation syndrome （OHSS） in patients undergoing in vitro fertilization-embryo transfer （IVF-ET）. Methods Enzyme-linked immunoadsordent assay （ELISA） was employed to measure the serum concentrations of VEGF and PEDF on the day of hCG administration, oocyte retrieval and embryo transfer, respectively. Based on OHSS classification of the criteria of Golan, 85 patients were divided into three groups. Patients in group A （n=10） showed symptoms of severe OHSS and patients in group B （n=13） suffered from moderate OHSS. The control group （group C, n=62） contained patients without symptoms of OHSS as well as patients with mild OHSS.Results In groups A, B and C, serum concentrations of PEDF on the day of hCG administration （h-PEDF）（166.54 ± 102.81 pg/ml, 159.45 ±136. 77 pg/ml, 172.05±170.95 pg/ml, P=0.48）, oocyte retrieval （o-PEDF）（176.91 ± 103.37 pg/ml, 122.52± 92.54 pg/ml, 179.82±177.47 pg/ml, P=0.27） and embryo transfer （e-PEDF）（169.02± 240.08 pg/ml, 136.80 ±139.21pg/ml, 157.38 ±222.54 pg/ml, P=0.95）, h-VEGF （175.55 ± 103.54 pg/ml, 218.84 ±179.70pg/ml, 153.39±145.06 pg/ml, P=0.36） and o- VEGF （171.93 ± 128.55 pg/ml, 220.36±149.82 pg/ml, 138. 74 ±% 139.30 pg/ml, P=0. 15） showed no significant differences. There was a statistical difference in serum concentration of e-VEGF between group A （197.04±156.63 pg/ml） and group C （110.69±49.55 pg/ml）（P=0.008）. The serum level of estradiol showed a positive correlation with the count of large follicles （r=0. 744）. The ratios of h-VEGF/h-PEDF, o-VEGF/o-PEDF and e-VEGF/e-PEDF were calculated and showed a clear difference among groups A, B and C （4.04±3.39, 2.10±2.14, 1.05± 4.80, P〈0.001; 4.54 5.69, 2.29 ±1.67, 0.94 ±0.59, P〈0.001; 5.43±6.16, 1.81±1.36, 2.42±2.60, P=0.04）. Conclusion While neither serum concentrations of VEGF nor PEDF can be used as an OHSS predictor, the ratios of h-VEGF/h-PEDF, o-VEGF/o-PEDF and e-VEGF/e-PEDF may have great predictive value.

Association of Genetic Polymorphisms of Anti-Müllerian Hormone (AMH) and Its Type II Receptor with Ovarian Hyperstimulation Syndrome

Objective To explore the association of genetic polymorphisms in the genes encoding the anti-Miillerian hormone （AMH） and its type H receptor （AMHRII） with ovarian hyperstimulation syndrome （OHSS）. Methods Using polymerase chain reaction （PCR） and DNA sequencing techniques, the exons of AMH and AMHRII were analyzed in 27 OHSS patients （OHSS group） and 22 non-OHSS patients （control group） who were applied controlled ovarian hyper- stimulation （COH）. Single nucleotide polymorphisms （SNPs） were also analyzed. Results SNPs G〉 T at position 146 of AMH exon 1 and G〉 A at position 134 of AMH exon 2 showed significant differences between the OHSS group and control group （P〈0.05）. SNP G〉 T at position 303 of AMH exon 1 showed no significant difference between the OHSS group and control group （P〉0.05）. No SNP was detected from the AMHR H exons 1 to 11 in either groups. Conclusion Genetic polymorphisms in the AMH gene may be a cause of ovarian hypersensitivity to exogenous hormone stimulation and the development of OHSS.

Hemorrhagic ovarian cyst without peritoneal bleeding in a patient with ovarian hyperstimulation syndrome: case report

Gynecologic and obstetric disorders presenting with abdominal pain are ectopic pregnancy,rupture of endometrial cysts, mature cystic teratoma and torsion of the adnexae. Hemorrhagic ovarian cysts, which included among the functional cysts, are often involved in acute abdomen leading to laparotomy intervention.

Acceleration of coasting enhances pregnancy rate in ICSI cycles at risk for ovarian hyperstimulation syndrome

Objective To assess the efficacy of adding Gn-releasing hormone antagonist（GnR HA） on the day of hC G triggering in a long luteal protocol without withholding the agonist in women who are at a risk to develop ovarian hyperstimulation syndrome（OHSS）.Methods This was a retrospective cohort study conducted upon 50 women who have elevated serum estradiol（E2） level 〉4 500 ng/L at the day of ovum triggering with hC G on a long agonist luteal protocol of controlled ovarian stimulation（COS）. When an exaggerated ovarian response was observed around day 10 of stimulation, immediately the next morning at 6 a.m. gonadotropin administration was stopped or reduced, and a single dose of ganirelix acetate（antagonist） was given sc continuation of the agonist dose hC G. Another serum E2 measurement was done at 6 p.m.（after 12 h of antagonist） then hC G, sc 250 mg and choriogonadotropin α were administered 14 h later after antagonist and documented the reduction of E2 level. Oocyte retrieval was conducted after 34-36 h of hC G administration. The measured outcomes were the level of E2 on the day of hC G injection, number of oocytes and their quality, pregnancy rate and the occurrence of OHSS and its grade in case it happened.Results The total dose for recombinant FSH was 25.3±6.4 ampoules（75 IU/ampoule） while it was 11.0±3.0 ampoules for the urinary hM G. A higher oocyte maturation rate（82.8%） and a high fertilization rate（87.8%） were observed. The mean endometrial thickness was 10.1±1.0 mm on the day of hC G triggering. The higher fertilization rate with the good endometrial thickness observed resulting in a higher pregnancy rate（78.0%, 39/50） with statistically significant（P〈0.05）. A significant reduction of E2 level was documented by a percentage around 40% before hC Ginjection. There were no reported cases of severe or moderate OHSS, however 13 cases（26%） were reported to have mild OHSS constituting.Conclusion Acceleration of coasting in cases of OHSS through treatment with GnR HA after pituitary suppression with GnR H agonist（GnR H-a） offered a novel approach to decrease E2 level, avoided cycle cancellation, and maintain excellent oocyte maturation rate, and finally result in high pregnancy rate with prevention of OHSS.

A Delayed Ovarian Hemorrhage with Severe Ovarian Hyperstimulation Syndrome after Transvaginal Ultrasound-guided Oocyte Retrieval for in vitro Fertilization-embryo Transfer

Objective To report a case of ovarian hemorrhage after transvaginal ultrasoundguided oocyte retrieval combined with severe ovarian hyperstimulation syndrome （OHSS）. Methods A 26-year-old woman who was on therapy for infertility presented with abdominal distension and a decrease of urine after transvaginal ultrasound-guided oocyte retrieval for in vitro fertilization-embryo transfer （IVF-ET）. Initial clinical presentation, ultrasound, and lab results were consistent with the diagnosis of severe OHSS. However with 4 d conservative treatments there seemed no recovery and the patient became more serious for her hemoglobin fell from 169.0 g/L to 60.2 g/L along with more abdominal fluid and a decrease of urine. Ultrasound guided paracentesis revealed an ovarian hemorrhage, and the patient underwent emergent surgery. Results The patient underwent emergent laparotomy for oophoroplasty and preservation of ovary. She got twin pregnancy in the second frozen-thawed embryo transfer （FET） cycle and delivered two female babies. Conclusion It is important to distinguish the OHSS from ovarian hemorrhage, because the ovarian hemorrhage with hemoperitoneum requires immediate operative management, whereas OHSS is nearly always managed conservatively. Clinicians must be aware that ovarian hemorrhage may be delayed in women presenting OHSS.

The application of in vitro maturation of oocytes in the infertile patients with polycystic ovarian syndrome

Objective:To evaluate the effects of in vitro maturation(IVM)of oocytes in the infertile pa-tients with polyeystic ovarian syndrome(PCOS).Methods:The infertile patients with PCOS who underwent IVM or IVF/ICSI from January2004 to August 2005 were studied retrospectively.68 unstimulated cycles(48 cases)underwentIVM as IVM group,42 cycles(39 cases)underwent IVF/ICSI as control group.Main outcomesincluding the number of oocytes retrival,the rates of fertilization,embryo cleavage,implanta-tion,pregnancy,miscarriage,ovarian hyperstimulation syndrome(OHSS)and multiple pregnan-cy were assessed.Results:No FSH was administered in IVM group and the mean number of FSH used was(25±6.2)ampoules in control group.When compared with control group,women in IVM grouphad significant increase in fertilization rate(70.7% versus 63.9%)and decrease in cleavage rate(87.9% versus 99.4%)and ovarian hyperstimulation syndrome(0 versus 7.1%).No significantdifferences between IVM group and control group were found in the number of oocytes obtained,implantation rate,clinical pregnancy rate,miscarriage rate and multiple pregnancy rate.Conclusion:Our results suggested that for infertile PCOS women who required assisted con-ception treatment,IVM is a more economical method with less OHSS complication than that ofconventional IVF treatment.

Minimum Dose of hCG to Trigger Final Oocyte Maturation and Prevent OHSS in a Long GnRHa Protocol

This paper was aimed to study the minimum dose of human chorionic gonadotropin （hCG） to effectively trigger maturation of oocytes and prevent ovarian hyperstimulation syndrome （OHSS） in a series of hyper-responders treated with a long gonadotropin releasing hormone agonist （GnRHa） proto- col. Six women at high risk of developing severe OHSS in a long GnRHa protocol were enrolled into this study. Serum hormone levels on the day of and after hCO administration, antral follicle count, oo- cyte retrieval number and quality were determined. In total, 6 women aged between 29 and 36 years and at risk of developing severe OHSS, received 2000 U hCG Five of them were treated with coasting for 1 day and the rest one for 4 days. The mean number of oocytes collected was 19 （range 14-27） and the fertilization rate per collected oocyte was 72.81%. Of the 6 women in the study, only one cancelled em- bryos transfer and all embryos were frozen, and then she delivered two health boys on term in the sub- sequent frozen-thawed embryo transfer （FET） cycle. Pregnancies and births were achieved in 3 patients out of 5 in vitro fertilization-embryo transfer （IVF-ET） cycles. No woman developed moderate or severe OHSS. Triggering with 2000 U hCG is feasible to prevent OHSS in unpredicted hyper-responders undergoing IVF in a long GnRHa protocol.

The Importance of Prolactin Levels in Patients Treated with Cabergoline for the Prevention of OHSS:Is Cabergoline Really Effective in Patients with High Risk of OHSS?

Background: OHSS is a dangerous and potentially life-threatening condition for which many researchers look for new ways to treat. Aim: To determine the effectiveness of prophylactic cabergoline administration on prolactine levels in patients with high risk for ovarian hyperstimulation syndrome (OHSS). Material and Methods: 163 in vitro fertilisation (IVF) patients with high risk for OHSS were enrolled in the study. The criteria for inclusion were more than 15 oocytes retrieved at oocyte pick up. A standard antagonist protocol was used for ovulation induction. Cabergoline treatments (0.5 mg/day) were started on the day of oocyte retrieval and continued for eight days. Prolactine levels were measured at the day of oocyte retrieval and the 9th day after the oocyte retrieval. Results: Of the 163 patients, 26 (15.9%) had OHSS. Prolactine levels on the day of oocyte retrieval were 44.22 ± 24.78 ng/mL and 37.6 ± 22.5 ng/mL in patients with OHSS and without OHSS, respectively (P > 0.05). In contrary prolactine levels were significantly higher in patients with OHSS patients (3.9 ± 5.07 ng/mL) than in patients without OHSS (2.1 ± 2.92 ng/mL) at the 9th day after oocyte retrieval (P < 0.05). Conclusion: Prolactine levels were higher in patients with OHSS than without OHSS who were treated with cabergoline for the prevention of OHSS.

Reducing the Trigger Dose of Human Chorionic Gonadotrophin Does Not Affect Final Oocyte Maturation and Subsequently Pregnancy Outcome of Frozen-thawed Embryo Transfer

To compare the efficacy of human chorionic gonadotrophin （hCG） at reduced doses of 2 000 IU and 3 000 IU for moderate or high responders with the dose of 5 000 IU in term of inducing final oocyte maturation for IVF/ICSI and the subsequent pregnancy outcome in frozen-thawed embryo transfer （FET）. Methods In the retrospective cohort study, 2 166patients undergoing IVF/ICSI with moderate or high response were recruited and classified into three groups according to the trigger dose of hCG： 2 000 IU （group A, n=722）, 3 000 IU （group B, n=722） and 5 000 IU （group C, n= 722）. The main outcome was the proportion of mature oocytes retrieved, fertilization rates, clinical pregnancy rates, cumulative pregnancy rates and incidence of ovarian hyperstimulation syndrome （OHSS）. Results No evidence of statistically difference was found in the proportion of mature oocytes retrieved （89.92%, 91.40%, 90.20%, respectively） and fertilization rate （79.8%, 80.07%, 80.51%, respectively） among groups A, B and C. Serum E2 level on the day of hCG injection, the number of mature oocytes retrieved and good-quality embryos in group A were significantly higher than those in group B and group C. Clinical pregnancy rates per transfer cycle （45.95%, 43.97% and 44.25%）, ongoing pregnancy rates （43.17%, 40.91% and 42,53%）, implantation rates （30, 74%, 2Z 78% and 29.86%） and cumulative pregnancy rates per patient （58.31%, 53.6% and 54.85%）A reduced hCG dose of 2 000 IUfor moderate or high responders leads