Effects of abnormal zona pellucida on fertilization and pregnancy in IVF/ICSI-ET

Objective To analyze the fertilization rate, embryo development and clinical outcome of oocytes with abnormal zona pellucida after in vitro fertilization(IVF) or intracytoplasmic sperm injection(ICSI).Methods A retrospective analysis included a total of 43 cycles(27 IVF cycles and 16 ICSI cycles) in which oocytes displaying abnormal zona pellucida were retrieved between January 2006 and December 2011. The fertilization rate, embryo quality,and the cumulative clinical pregnancy rate were analyzed.Results Rescue ICSI was applied in 27 IVF cycles in which failed extrusion of the second polar body after conventional IVF was observed, and of them, complete failure to fertilize occurred in 23 IVF cycles. The fertilization rate and the normal fertilization rate for IVF(64.83% and 59.32%, respectively) were significantly lower than those for ICSI(85.19% and 79.01%, respectively), whereas the cleavage rate(94.12%) with IVF did not differ significantly from that with ICSI(95.65%, P>0.05). The percentages of good-quality embryos in IVF group(52.67%) and ICSI group(43.75%) also did not differ significantly(P>0.05). Although the rates of implantation and pregnancy appeared to be greater in IVF group(33.33% and 40.00%, respectively) compared with those in ICSI group(25.00% and 35.71%, respectively), the differences were not significant(P>0.05).Conclusions ICSI should be carried out for oocytes with abnormal zona pellucida,for which the risk of IVF failure is high. Rescue ICSI improves the likelihood of fertili-zation of oocytes with abnormal zona pellucida, but cannot improve the clinical outcome.     

Immunofluorescent Study of Human MⅡ Oocytes Failed to Fertilize after IVF and ICSI

Objective To discuss the reason why human M Ⅱ oocytes failed to fertilize after IVF and ICSI. Methods The unfertilized human MⅡ oocytes were collected 24-48 h after IVF and ICSI and stained for immunoflurescence and PI counterstain. The types of fertilization failure were identified under the fluorescence microscopy. Results About 55.8% oocytes in IVF were found no sperm in them, which were more than that in ICSI （9.7%） （P〈0.01）. About 14.9% oocytes in IVF and 58.1% in ICSI displayed oocyte activation failure. The difference was significant （P〈0.01）. Defects in pronuclear formation and or migration was found in a similar proportion of oocytes both after IVF （25.3%） and ICSI （32.3%）（P〉0.05）. There were 3.9% oocytes with other abnormalities were observed in IVF but none in ICSI. Conclusion The main reason of fertilization failure after IVF was no sperm penetration. However fertilization failure after ICSI was mainly associated with incomplete oocyte activation.     

Selective Short-term Fertilization Combined with Early Rescue ICSh An Optimal Strategy for Patients at High Risk for Fertilization Failure

Objective To investigate clinical outcomes in patients who were at more precise criteria risks for fertilization failure and were treated with selective, short-term fertilization （oocytes and sperm co-incubated for 4 h） and early rescue intracytoplasmic sperm injection （ICSI）. Methods A retrospective analysis was performed on 2023 women undergoing assisted reproductive technology （ART）. They were assigned to 4 groups： short-term in vitro fertilization （short-term IVF,, group A, n=217）, regular IVF （oocytes and sperm coincubated overnight, group B, n=1475）, short-term IVF and early rescue ICSI （shortterm ICSI, group C, n=94）, and regular ICSI （group D, n=237）. Results In group A, 69.8% （217/311） achieved normal fertilization rates, and the complete fertilization failure rate （fertilization rate was 0%） was 12.9% （40/311）. But all of the fertilization failure oocytes got rescue ICSI. In group B, the complete fertilization failure rate was 1.1% （19/1 692）. The fertilization rate, 2 PN （pronucleus） rate, and i PN rate were significantly lower in group A than those in group B （70.9% vs 80.8%, 57.8% vs 66.3%, and 3.5% vs 6.2%, respectively）. No significant differences were observed in clinical pregnancy rates and birth defect rates between groups A and B. The fertilization rates in groups C and D did not significantly differ （77.9% vs 76.2%）, which was also true for birth defect rates. The clinical pregnancy rate of group C was higher than that of group D （51.2% vs 42.3%）, but this difference was not significant （P〉0. 05）.Conclusion These results suggested that selective, short-term fertilization can result in effective outcomes for patients who were at high risk for fertilization failure.     

Impact of Semen Liquefaction and Viscosity on the Outcomes of in vitro Fertilization

Objective To compare the outcomes of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) between semen liquefaction and viscosity with normal and abnormal. Methods Semen that liquefied within 60 min and normal viscosity was assigned to the normal group, while semen that unliquefied more than 60 min or high viscosity was assigned to abnormal group. Equal volumes of culture medium were added to abnormal group and normal control group, followed by repeated pipetting, to induce liquefaction. Sperm parameters, fertilization and cleavage rates, good-quality embryo rate, implantation rate and pregnancy rate were analyzed. Results The abnormal group ratio was much higher in the ICSI group (30.5%) than in the IVF group (21.9%) (P<0.05). The age of the husbands and total progressive motility (PR) sperm in abnormal IVF group were higher than those in normal IVF group (P<0.05). Fertilization rate (80.7%) in the abnormal IVF group was higher than that in the normal IVF group (75.6%) and normal control group (P<0.05). There were no differences in outcomes of the ICSI patients between the normal and abnormal groups. There was no difference between normal group and normal control group. Conclusion Equal volume of culture media was added to non-liquefied semen may be used to high viscosity and unliquefied semen, and may have a positive effect on fertilization outcomes.     

Rescue ICSI: Choose the Optimal Rescue Window before Oocyte Aging

Objective To evaluate the application value of rescue ICSI in fertilization failure after conventional IVF and choose the best rescue window before oocyte aging according to the results of rescue ICSI performed in different time. Methods The data of 93 IVF cycles were analyzed retrospectively. Rescue ICSI was performed in these cycles after conventional IVF failure. Because of the different rescue time, these cycles were divided into two groups: early rescue group (group A, 77 cycles, rescue ICSI performed 4-8 h after conventional IVF) and late rescue group (group B, 16 cycles, rescue ICSI performed 20-22 h after conventional IVF). Results There were no statistically significant differences in age of female, duration of infertility, number of oocytes retrieved every cycle. The normal fertilization rate, pregnancy rate and implantation rate were decreased in group B compared with those in group A (P<0.05). In group A, the normal fertilization rate of rescue ICSI performed 4-6 h after conventional IVF (group A1) was increased compared with that of rescue ICSI performed 6-8 h (including 6 h) after conventional IVF (group A2)(66.5% vs 55.9%)(P<0.05); while the abnormal fertilization rate in group A1 was decreased compared with group A2 (9.0% vs 14.4%)(P<0.05). Clinical pregnancy rate was slight higher in group A1 than in group A2, though this failed to be significantly different. Conclusion Rescue ICSI is effective if fertilization was failure after conventional IVF, the most important thing is to choose the reasonable rescue window before oocyte aging when ICSI is performed.     

Effect of interval after surgery on in vitro fertilization/ intracytoplasmic sperm injection outcomes in patients with stage III/IV endometriosis

Background For patients with severe endometriosis, the spontaneous pregnancy rates have been reported to be near 0 due to extreme distortion of normal pelvic anatomy.Surgery is one of the treatment options; however, if patients failed to conceive after surgery, in vitro fertilization （IVF） is effective.The objective of this retrospective study was to determine the clinical characteristics of IVF/intracytoplasmic sperm injection （ICSI） in patients with stage Ⅲ/Ⅳ endometriosis, and to determine the impact of the interval from surgery to IVF/ICSI on outcome.Methods One hundred and sixty patients who were diagnosed with stage Ⅲ/Ⅳ endometriosis underwent IVF/ICSI cycles between February 2004 and June 2009 were enrolled.The mean interval from surgery to IVF, number of oocytes retrieved, fertilization rate, implantation rate, embryos transferred, and good embryos transferred were compared between two age groups （≤35 years and 〉 35 years）.Results The mean interval from surgery to IVF was （37.9±28.9） months for the group ≤ 35 years of age and （57.6±39.7）months for the group 〉35 years of age.Twenty-five IVF/ICSI cycles （12.8%） were performed during the first year after surgery, and 34.9% IVF/ICSI cycles were performed 2 years after surgery.No significant differences existed between the two groups with respect to the fertilization rate, implantation rate, number of embryos transferred, number of good embryos,clinical pregnancy rates, live birth rates, and cumulative clinical pregnancy rates （P 〉0.05）.The probability of cumulative clinical pregnancies was 75%, 50%, and 25% （（29.0±4.8）, （61.0±7.6）, and （120.0±16.9） months after surgery, respectively）.Conclusions For infertile patients with stage Ⅲ/Ⅳ endometriosis, the optimal time to conceive by IVF/ICSI is 〈2 years after surgery; nevertheless, most of the patients took a longer time to conceive.     

The Effects of Murine Cytomegalovirus on the Maturation, Fertilization, Cleavage and Blastula Formation of Mouse Oocytes In Vitro

To study the effects of mouse cytomegalovirus （MCMV） on the in vitro maturation, fertilization, cleavage and blastula formation of mouse oocytes, the immature oocytes were infected in vitro by MCMVs of different dosages （100 TCID50, 10 TCID50 and 1 TCID50）. The oocytes were then observed for in vitro maturation, fertilization, cleavage and blastula formation and the ultrastructural changes after the culture with the viruses. Our results showed that no significant differences were found in IVM, IVF, cleavage and blastula formation among the groups treated with of virus of various dosages. And ultrastructural abnormality was observed in the oocytes treated by 100 TCID50 of viruses. It is concluded that MCMV did not have any conspicuous effects on IVM, IVF, cleavage and blastula formation of murine immature oocytes.     

Effect of Incubation Temperature and Warming Solutions on the Viability and Maturation of Vitrified-thawed Human Immature Oocytes

Objective To investigate the viability and maturation of frozen-thawed human immature oocytes exposed to different temperature of vitrification and warming solutions. Methods The immature oocytes in germinal vesicle (GV) and matephase I (MI ) stages were collected from our ICSI patients and exposed to different temperature of vitrification and warming solutions before frozen in the freezing/thawing procedures. The different temperature groups were as follows: Group A, equilibration solution at 37℃, vitrification solution at room temperature, warming solution at 37℃; Group B, both vitrification and warming solution at room temperature; Group C, both vitrification and warming solutions at 37℃; Group D, the frozen-thawed oocytes and the fresh oocytes were cultured for in vitro maturation. The survival rate and maturation rate were compared among groups. The oocytes were examined using immunofluorescent stainingand confocal microscopy to check the spindle configuration and chromosome arrangement. Results The survival rates and MII rates of GV stage oocytes in groups A, B, C were 100%(15/15), 81.3%(13/16), 68.8%(11/16) and 33.3%(2/6), 83.3%(10/12),72.7%(8/11), respectively. The survival rate of group C was significantly lower than that of the control (P<0.05). The normal spindle and chromosome configuration were only observed in group B, with the rates of 20% (2/20) and 10% (1/10), respectively. The survival rates of MI stage in groups A, B, C were 71.4%(10/14), 100% (12/12) and 83.3%(10/12), no significantly difference from that of the contro1(100%, 14/14). The MII rates of MI stage in groups A, B and C were 0%(0/14), 66.7%(8/12) and 80% (8/10), respectively. The MⅡ rate in group A was significantly lower than that in other groups (P<0.01). Only one oocyte in group C was found with normal spindle and chromosome configurations. Conclusion The appropriate operation temperature of vitrification and warming solutions can improve the outcomes of the vitrified-thawed human immature oocytes.     

A live birth of activated one-day-old unfertilized oocyte for a patient who experienced repeatedly near-total fertilization failure after intracytoplasmic sperm injection

Total or near-total fertilization failure after intracytoplasmic sperm injection (ICSI) is a rare event, but it occurs repeatedly because of sperm defects in activating oocyte. The case presents a successful pregnancy and live birth after calcium ionophore A23187 (A23187) activation on one-day-old unfertilized oocytes in a patient whose husband suffered oligoasthenoteratozoospermia, and who had experienced repeated near-total fertilization failure after ICSI. In the second ICSI cycle, only one oocyte was fertilized while nine were unfertilized. Oocyte activation with A23187 were performed on the one-day-old unfertilized oocytes after ICSI and resulted in fertilization and embryo transfer. A clinical pregnancy was achieved and a healthy baby was born. To our knowledge, this is the first reported case of a healthy birth after oocyte activation on the one-day-old unfertilized oocyte. This indicates that “rescue oocyte activation” on one-day-old unfertilized oocytes after ICSI may be helpful for preventing total or near-total fertilization failure after ICSI.

     

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     

Is there A Link between Serum Thyroid Stimulating Hormone Level and the Results of in vitro Fertilization and Embryo Transfer？

Objective To analyze the clinical features and outcomes in infertile patients with different levels of thyroid stimulating hormone (TSH) undergoing IVF/ICSI, and to investigate whether inappropriate level of TSH has the adverse effect on the results of the IVF-ET. Methods A total of 389 patients undergoing IVF/ICSI from January 2009 to December 2011 were divided into 3 groups according to the basal TSH level: group A (TSH< 2.0 mIU/L), group B (TSH 2.0-4.5 mIU/L) and group C (TSH>4.5 mIU/L). Oocyte retrieved, fertilization rate, cleavage rate, available embryo rate, pregnancy rate and miscarriage rate were analyzed to explore whether serum TSH level was correlated with the results of IVF/ICSI. Results There were no differences in number of oocyte retrieved, fertilization rate, cleavage rate and available embryo rate among 3 groups (P>0.05). Clinical pregnancy rate in group B (43.0%) was significantly higher than that in group A (30.2%) and group B (23.5%), respectively (P<0.05). There were no significant differences in miscarriage rate among 3 groups. Conclusion TSH level has no effect on fertility rate or miscarriage rate in patients undergoing IVF/ICSI. Inadequacy TSH level would decrease the IVF/ICSI pregnancy rate.     

Revised Super-long Down-regulation Protocol Improves the Outcome of Infertile Patients with Repeated Implantation Failure in IVF/ICSI-ET

Objective To investigate the outcome of revised super-long down-regulation protocol （RSDP） for in vitro fertilization / intracytoplasmic sperm injection-embryo transfer （1VF/1CS1-ET） in the special infertile patients with repeated implantation failure （RIF）. Methods Patients with RIF were divided into RSDP group and routine long downregulation protocol （RLDP） group. In RSDP group, gonadotropin releasing hormone agonist （GnRHa） was injected intramuscularly by 2.5 mg in mid-luteal phase for the ftrst time and 1.25 mg after 28 d; gonadotropin （Gn） was started 14 d later after the second GnRHa dose. IVF/ICSI-ET was performed according to the routine procedure. The clinical outcomes of RSDP group were compared with those of RLDP group. Results In RSDP group, the number of retrieved oocytes and valid embryos was significantly lower （P〈0.05）; there were no significant differences about fertilization rate （P〉0. 05）; both good-quality embryo rate and implantation rate were significantly increased （P〈0. 005）; clinical pregnancy rate was obviously improved （P〈0. 05）, as compared with RLDP group.Conclusion RSDP can improve the IVF outcomes significantly in RIF patients.     

Impact of Blood Clot in Oocyte-Corona-Cumulus Complex during in vitro Fertilization and Embryo Transfer

Objective To study the impact of blood clots in the oocyte-corona-cumulus complexes (OCCC) during in vitro fertilization and embryo transfer (IVF-ET). Methods The OCCCs were harvested from the patients undergoing long protocol ovarian hyperstimulation. The OCCCs with blood clots removed or not, were randomly grouped into A or B. The OCCCs without blood clots were group C (the control). Results The patient’s age, infertility duration, the average GN consumption, the average days of superovulation and an average number of harvested oocytes showed no significant difference in the 3 groups. The fertilization rate and 2PN rate in group A were the highest, which were 85.4% and 71.1%, respectively, followed by group C, which were 77.5% and 64.9%, respectively. The lowest fertilization rate and 2PN rate were in group B, 75.8% and 62.2%, respectively. Those in group A were significantly higher than those in groups B and C (P<0.01), while there was no significant difference between group B and group C . The implantation rates and pregnancy rates showed no significant difference in the 3 groups after transplantation, even if group A got the highest rate among the 3 groups. Conclusion Removing the blood clots in OCCC can improve the outcome of IVF-ET without increasing the cost and complexity of the operation.     

The role of brain-derived neurotrophic factor in mouse oocyte maturation <Emphasis Type="Italic">in vitro</Emphasis>

Brain-derived neurotrophic factor (BDNF) can promote developmental competence in mammalian oocytes during in vitro maturation (IVM),but the role of BDNF in oocyte maturation at cellular level is not still clear.In this study,mouse cumulus-enclosed oocytes subjected to IVM were fertilized and cultured to blastocyst stage.Meiotic spindle configuration and cortical granules distribution during oocyte maturation in vitro were assessed by using immunofluorescence and laser confocal microscopy.The results showed that BDNF contributed to the complete preimplantation development of mouse oocytes compared to the control oocytes (13.78% vs.5.92%;P<0.05).Further,BDNF did not accelerate nuclear maturation of IVM oocytes.For the BDNF-treated oocytes at meiosis Ⅰ,Meiotic spindle areas were significantly smaller and the number of cytoplasmic microtubule organizing centers was greater than that in the control,and the percentages of oocytes showed spindles positioned near the oolemma and a well-formed cortical granule-free domain were significantly higher than that of the control.These morphological characteristics of the BDNF-treated oocytes were much closer to the oocytes matured in vivo than those of the control oocytes.In conclusion,BDNF can promote the developmental competence of mouse IVM oocytes,by improving the meiotic spindle configuration and location and cortical granules distribution at meiosis Ⅰ.     

Factors Relating with Fertilization Failure in Conventional IVF-ET Cycles

Objective To analyze the factors relating with fertilization failure in conventional IVF cycles. Methods The total fertilization failure rate of 2429 IVF cycles from January 2011 to May 2012 in the Reproductive Centre of the Women and Children Hospital of Jiangxi Province were retrospectively analyzed. Risk factors were identified by univariate and multivariate logistic regression analyses. Results The total fertilization failure rate of conventional IVF-ET rate was 5.7% (139/2429). The percentage of morphologically normal sperm (11.1±5.8% vs 13.4±5.3%), progressive motility (47.4±10.5% vs 50.1±8.6%), percentage of couple primary infertility (79.1% vs 44.3%), percentage of female primary infertility (69.1% vs 36.3%), percentage of male primary infertility (74.8% vs 41.7%), percentage of without oviduct obstruction patients (30.2% vs 13.6%) and percentage of couples primary infertility (79.1% vs 44.3%) of the fertilization failure patients were significantly different from those of the fertilized patients (P<0.05). Besides, higher total fertilization failure rate was found in couples with isolated teratozoospermia than in couples with normal percentage of morphologically normal sperm (15.0% vs 5.2%). After that, it was found by multivariate logistic regression analyses that many factors including percentage of morphologically normal sperm, sperm concentration, couples primary infertility and female infertility years were related with fertilization failure. Conclusion Patients with low percentage of morphologically normal sperm (<4%), low sperm concentration and motility, male primary infertility, female primary infertility, without oviduct obstruction, long female infertility years or/and couples primary infertility are at high risk of fertilization failure. More attention should be paid to these patients for avoiding the fertilization failure.     

A frozen-thawed embryo transfer program improves the embryo utilization rate

Background Frozen-thawed embryo transfer （FET） is the most common way to prevent serious late ovarian hyperstimulation syndrome and increase the cumulative pregnancy rate. We evaluated the effectiveness of an FET program for improving the embryo implantation and clinical pregnancy rates, and ultimate embryo utilization rate in infertility treatment. Methods Patients undergoing in vitro fertilisation （IVF） cycles from January 2006 to June 2008 were enrolled, including 179 patients who had undergone the first FET cycle after controlled ovarian hyperstimulation （COH） in which all embryos were frozen （group C1） and 1306 patients who had COH with fresh embryo transfer （ET） （group T1）. Logistic regression was used to model the embryo implantation and clinical pregnancy rates based on the mother＇s age, numbers of oocytes retrieved, embryos transferred and high-quality embryos transferred. The embryo implantation and clinical pregnancy rates were also compared between two groups after adjusting for age, the numbers of oocytes retrieved and the numbers of embryos transferred. Results Logistic regression analysis confirmed that embryo implantation and clinical pregnancy rates in group C1 were both significantly higher than those in group T1 after adjusting for confounding factors （43.6% vs 29.0%, 63.1% vs 47.0%, respectively; P 〈0.01）. The embryo implantation and clinical pregnancy rates were consistently higher in group C1 by comparing the age groups ≥35 or 〈35 years. The clinical pregnancy rates for the numbers of oocytes retrieved per cycle being ≥15 or 〈15 were higher in group C1, as was the embryo implantation rate. These differences were statistically significant for oocyte numbers 〉15 （P 〈0.05）. The embryo implantation and clinical pregnancy rates in group C1 were both significantly higher than in group T1 when two or three embryos were transferred （P 〈0.05）. Conclusion A program of freezing all embryos and performing FET improved the rates of embryo implantation and clinical pregnancy, and ultimately enhanced the embryo utilization rate.     

Relationship between Different Pronuclear Patterns and Potential of Embryo Development and Pregnancy

Objective To explore the relationship between the patterns of pronucleus and embryo development and pregnancy potential in the pronuclear stageand. Methods According to the number and distribution of nucleolar precursor bodies, the embryos at pronuclear stage were classified into 6 pronuclear patterns from 0 to g, 16～18 h after in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). For each pattern, the subsequent embryonic morphology and the pregnancy rate were analyzed. Results Embryos of Pattern 0 developed to significantly more embryos with good quality and higher pregnancy potential than the embryos developing from other patterns (83. 14% and 76. 11% respectively, P＜0. 05). The pregnancy rate was decreased as less embryosgroups of only Patternof O,attern O were transferred . The pregnancy rate of the with Pattern O, and withoutPattern O were 48. 08%, 32. 14% and 21.28% respectively (P＜0. 05). Conclusions The pronuclear patterns are of the predictive value of embryo development and pregnancy potential, which can be used as a new tool for the selection of embryos in IVF and ICSI.     

Outcome of in vitro fertilization in endometriosis-associated infertility: a 5-year database cohort study

Background  Endometriosis affects natural fertility through various approaches, and in vitro fertilization (IVF) is a good treatment. But the IVF result of endometriosis patients is still under debate. We investigated the effect of endometriosis on IVF by analyzing the data from a single reproductive center.

Methods  A retrospective, database-searched cohort study was performed. Relevant information was collected from the electronic records of women who underwent IVF/intracytoplasmic sperm injection between January 2006 and December 2010 in the Assisted Reproductive Unit of Sir Run Run Shaw Hospital. Patients with endometriosis were enrolled the study group. The rest of the women formed the control group. The main outcome was the clinical pregnancy rate. Secondary outcomes were oocytes retrieved number, fertilization rate, high-quality embryo rate, number of high-quality embryo for embryo transplantation, and implantation embryo/high-quality embryo ratio (IE/HQE ratio). Comparisons were performed by the  c²-test and independent t-test.

Results  The endometriosis group (n=177) had a markedly lower oocytes retrieved number, fertilization rate, implantation rate, and clinical pregnancy rate (7.6±5.1, 63.6%, 27.7%, and 45.2%, respectively) compared with the non-endometriosis group (n=4267; 11.8±7.3, 68.4%, 36.2%, and 55.2%, respectively).  Stratified analysis showed that this difference was found in the subgroup younger than 35-years old, while only fertilization rate and implantation rate were different in the elder subgroup. The ratio of high-quality embryos transferred is lower in endometriosis group (53.7% vs. 71.8%, P <0.05), but there is no difference in IE/HQE ratio between two groups. There is no significant difference in fertilization rate, implantation rate, and clinical pregnancy rate between mild and severe endometriosis patients.

Conclusions  Endometriosis patients suffer a decreasing IVF pregnancy rates mainly caused by reducing oocytes number and fertilization rate, regardless of the severity of the disease. Appropriate intracytoplasmic sperm injection manipulation might improve the outcomes of IVF.

     

Comparison of the Effects and Safety of Mild Ovarian Stimulation and Conventional Ovarian Stimulation with A Long GnRH Agonist Protocol on IVF Outcomes

Objective To conduct a Meta-analysis of studies that compared the efficacies of mild ovarian stimulation and conventional long GnRH agonist protocol in patients under- going IVF or intracytoplasmic sperm injection （ICSI）. Methods Meta-analysis was performed. All studies were published by July 2012 with data related to outcomes following mild ovarian stimulation compared with the conventional protocol. Odds ratios （ORs） and weighted/standardized mean difference （WMD/SMD） from individual study were pooled in fixed and random effect models. Main outcome measure was the efficacy of mild ovarian stimulation. Results Six articles were included in this Meta-analysis. The number of oocytes retrieved was lower, the cycle cancellation rate was higher and the incidence of ovarian hyperstimulation syndrome （OHSS） was lower in the mild stimulation group than in conventional ovarian stimulation group. Clinical pregnancy rates were similar in both mild and conventional stimulation groups. Conclusions The level of evidence supporting the use of mild stimulation protocols in IVF is low, considering the fewer oocytes retrieved and the higher rates of cycle cancellation.     

Presence of Meiotic Spindles Indicates Early Cleavage of Embryos

Objective To assess whether the detection of the meiotic spindle could anticipate the appear- ance of early cleavage. Methods Oocytes were obtained from stimulated ovaries of consenting patients undergoing oocytes retrieval for ICSI. Spindles were imaged with the Polscope. After ICSI, oocytes with or without spindles were cultured for examination of early cleavage and embryo development. A total of 328 oocytes from 50 cycles were examined with the Polscope and inseminated by ICSI. Results Spindles were imaged in 81.7% of oocytes. After ICSI, more oocytes with spindles (78.4%) fertilized normally than oocytes without spindles (53.3%) (P<0.001). At 25-27 h post ICSI, more fertilized oocytes developed from oocytes with spindles (81.9%) were detected early cleavage than those from oocytes without spindles (28.1%) (P<0.001). Significantly more embryos with early cleavage (82.2%) developed to high quality embryos at d 3 compared with the embryos without early cleavage (48.3%) (P=0.001). The value of rs related to the relation- ship between spindles and early cleavage was 0.420 (P<0.001). Conclusion The existing of the early cleavage may have a predictive value on the opportunity of high quality embryos and the existing of the spindle may have a predictive value in the appearance of early cleavage.