Transfer of cryopreserved-thawed pre-embryos in a cycle using exogenous steroids without prior gonadotrophin-releasing hormone agonist suppression yields favourable pregnancy results

We have analysed the use of a programmed cycle of administration of exogenous steroids without prior suppression with a gonadotrophin- releasing hormone agonist (GnRHa) for the transfer of cryopreserved- thawed pre-embryos. From July 1992 to June 1994, 199 cycles (162 patients) were studied. Pre-embryos had been previously cryopreserved at the pronuclear stage using 1.5 M 1,2-propanediol as a cryoprotectant. Preparation of the endometrium was achieved in a step- up regime with transdermal oestradiol patches (0.1 to 0.4 mg). Progesterone in oil (50 mg i.m.) was started on cycle day 13. Pre- embryos were thawed on day 14 and transferred on day 15 after evidence of survival and cleavage. The mean (+/- SD) age of patients undergoing transfer was 35.4 +/- 4.3 years. The mean number of pre-embryos thawed was 4.7 +/- 1.8 with a mean of 3.3 +/- 1.4 pre-embryos being transferred. Eight of the cycles demonstrated follicular development >16 mm prior to thaw and transfer; however, these patients did not demonstrate a luteinizing hormone surge. Mean endometrial thickness on day 13 was 10.8 +/- 2.1 mm. Overall pregnancy rate was 29.2% (57/195). The ongoing or delivery rate was 16.1% (32/195). The rate of preclinical losses per transfer was 6.2% (12/195). Overall, the implantation rate was 6.2% (47/757). Thus, the use of a programmed cycle for cryopreserved embryo transfer yields favourable pregnancy outcome and offers practical advantages to patients. Prior suppression with a GnRHa is not necessary for endometrial preparation.      

Effect of developmental stage of embryo at freezing on pregnancy outcome of frozen-thawed embryo transfer

BACKGROUND: The study aim was to investigate the impact of the developmental stage of embryos on pregnancy outcome of frozen embryo transfer (FET). METHODS: The survival rates of embryos after thawing and pregnancy outcome following FET were compared retrospectively between three cryopreservation strategies utilizing either zygote, day 2 or day 3 embryo freezing. RESULTS: A total of 4006 embryos was analysed in 1657 thaw cycles. The highest (P < 0.0001) survival rate (all cells survived) was observed for zygotes (86.5%), followed by day 2 (61.7%) and day 3 (43.1%) embryos. FET was performed in 1586 (95.7%) of all thaw cycles, resulting in overall clinical pregnancy and implantation rates of 20.7 and 14.2% respectively. The delivery rate per transfer was 16.5%, and live birth rate per transferred embryo 11%. There were no significant differences in clinical pregnancy, implantation, delivery and birth rates between frozen zygote, day 2 and 3 embryo transfers. However, an elevated miscarriage rate was observed in the day 3 group (45%) compared with zygotes (21.3%; P = 0.049) and day 2 embryos (18.3%; P = 0.004). The overall efficacy of FET (birth rate per thawed embryo) was 7.3%. The efficacy was lower in day 3 group (4.2%) than in the zygote (7.1%; P = 0.082) and day 2 (7.6%; P = 0.027) groups. CONCLUSIONS: The developmental stage of embryos at freezing has a profound effect on their post-thaw survival, but seems to have little effect on rates of clinical pregnancy, implantation, delivery and birth after FET. The elevated miscarriage rate for day 3 frozen embryo transfers may be caused by damage during freeze-thaw procedures. The low survival rate and elevated miscarriage rate were both responsible for a reduced overall efficacy for day 3 FET when compared with zygotes and day 2 embryos.     

激素替代治疗周期402例冻融胚胎移植的回顾性分析

目的回顾性分析激素替代治疗（hormone replacement therapy, HRT）周期冻融胚胎移植（frozen - thawed embryo transfer, FET）的妊娠结局并探讨其影响因素。方法回顾性分析2011年1月～2012年1月中山大学附属第一医院生殖中心接受激素替代治疗周期冻融胚胎移植的不孕患者的妊娠结局和其相关因素。结果研究期间366个患者行402个HRT周期冻融胚胎移植,临床妊娠率为41．5％,年龄≤35岁患者妊娠率为43．4％;〉35岁患者妊娠率为27．7％。多胎率为29．9％,种植率为22．4％,其中D3天胚胎种植率为19．7％,囊胚种植率为37．7％。接受单个胚胎移植的患者,D3天胚胎种植率为9．1％,囊胚种植率为53．3％。结论激素替代周期冻融胚胎移植能获得满意种植率,影响其临床妊娠率因素包括女方年龄、ET日雌激素水平,以及ET胚胎数目、类型和质量。     

Reduced pregnancy rates following the transfer of human embryos frozen or thawed in culture media supplemented with normal serum albumin

Over a 26 month period 17% of couples having treatment in our clinical programmes selected a commercially available protein (normal serum albumin, NSA) prepared from pooled human sera instead of using their own serum as a supplement for their embryo culture media. In a retrospective analysis of >2000 gonadotrophin-stimulated cycles and 1000 cycles where frozen/thawed embryos were transferred, fertilization, embryo quality and pregnancy rates following in-vitro fertilization (IVF), gamete intra-Fallopian transfer (GIFT) or intracytoplasmic sperm injection (ICSI) were unaffected by the type of protein used to supplement the culture medium. When embryos were thawed in medium containing NSA, both pregnancy (PR) and implantation rates (IR) were significantly lower (P <0.05) than if the medium was supplemented with serum (PR 8.3% and 17.5%; IR 4.6% and 10.5%). Inclusion of NSA before freezing reduced the IR of thawed embryos. To further test this observation all cycles where embryos were cultured and frozen in medium containing NSA (173 cycles) were matched to cycles where serum was used and the outcome was compared. At the end of 1995 just over half of the embryos in both groups had been thawed. No statistical difference was noted in the pregnancy rates (NSA, 5.6% versus serum, 11.3%) but the IR per embryo was significantly lower when embryos were cultured and frozen in medium supplemented with NSA (2.2%) than when serum was used as the supplement (6.6%).      

睾丸精子冻融后行卵胞浆内单精子注射术在无精子症患者中的临床应用

目的探讨对无精子症患者实施睾丸精子经冷冻复苏后行卵胞浆内单精子注射术（ICSI）的临床效果。方法回顾性分析了既往在我中心有冷冻睾丸精子的34个ICSI周期,评估其冷冻精子复苏、卵子受精、卵裂、可移植胚胎、优质胚胎、临床妊娠及其分娩情况。结果 34个拟定复苏冷冻睾丸精子的周期精子复苏均获得成功,受精率为76.9%（249/324）,2PN受精率69.7%（226/324）,卵裂率98.8%（246/249）,可利用胚胎率84.2%（207/246）,优质胚胎率46.3%（114/246）;所有周期均有胚胎移植;34个周期中行新鲜胚胎移植30个,种植率为34.4%（21/61）,临床妊娠17例（临床妊娠率56.7%）包括13例单胎和4例双胎,其中1例单胎妊娠流产（流产率为5.9%）。目前,有14个周期已经出生了18个健康婴儿（10个男婴,8个女婴）未发现先天缺陷儿,另2例单胎继续妊娠中（32＋w,29＋w）。结论睾丸精子经冷冻后有很好的复苏率,结合ICSI受精可以得到较好的临床结局。     

121例冻融胚胎移植周期回顾性分析

目的探讨影响冷冻胚胎复苏移植妊娠率的因素。方法收集2010年01月到2011年12月份在本中心进行冷冻胚胎解冻移植121个周期的资料,进行回顾性分析。结果 （1）121个周期中有35个周期获临床妊娠,周期临床妊娠率为28.92%;（2）妊娠组与非妊娠组间解冻后胚胎的优质胚胎率有显著性差异（P〈0.05）;（3）自然周期和激素替代周期间妊娠率无显著性差异（P〉0.05）,但在激素替代周期中妊娠组与非妊娠组间E2水平有显著性差异（P〈0.05）;（4）D2及D3冷冻胚胎复苏移植,妊娠率上亦无显著性差异（P〉0.05）。结论优质胚胎是冻融胚胎移植周期获得妊娠的关键,在激素替代周期中较高的雌激素水平更有利于胚胎的着床。     

Day 2 elective single embryo transfer in clinical practice: better outcome in ICSI cycles

BACKGROUND: Single embryo transfer (SET) after IVF/ICSI has been shown to result in an acceptable pregnancy rate in selected subjects. In our unit, SET is routinely carried out among women under the age of 36 in the first or second treatment cycle when a top-quality embryo is available. In order to define further the selection criteria for SET, we have analysed the outcome of elective SET (eSET), including the cumulative pregnancy rate after frozen embryo transfers, performed in the years 2000-2002 in the Oulu Fertility Center. METHODS: During the study period, a total of 1271 transfers were performed, and in 468 cycles SET (39% of all transfers) was carried out. Of the SET cycles, in 308 cases a top-quality embryo was transferred on day 2 and extra embryos were frozen. Of these eSET cycles, ICSI was carried out in 87 cycles (28%). RESULTS: The overall clinical pregnancy rate per transfer was 34.7% in the eSET cycles. In the eSET ICSI cycles, the clinical pregnancy rate was significantly higher than in the corresponding IVF cycles (50.6 versus 28.5%, P < 0.001). The cumulative pregnancy rate per patient after fresh and frozen embryo transfers was also significantly higher after ICSI (71.2 versus 53.4%, P < 0.01). CONCLUSIONS: A high cumulative pregnancy rate per oocyte retrieval can be achieved after eSET in daily clinical practice. The implantation rate of fresh top-quality embryos in the ICSI cycles was significantly higher than in the IVF cycles, possibly due to more successful selection of the embryo for embryo transfer on day 2 after ICSI. In addition, our data suggest that embryo quality is a more important determinant of outcome than the age of the woman.     

Elective single embryo transfer: the value of cryopreservation

In-vitro fertilization is associated with a high rate of multiple pregnancies, a consequence of the number of embryos transferred. There is a challenge in avoiding even twin pregnancies in assisted reproduction, and this can be accomplished with elective single embryo transfer and a good cryopreservation programme. In our follow-up study, we analysed all our elective single embryo transfers during 1998-1999. In all these cycles at least one embryo was frozen. A total of 127 elective single embryo transfers were performed with a clinical pregnancy rate of 38.6%. The highest implantation rate was obtained with four-cell embryos with <10% fragmentation (39.8%). Thirty-four patients have delivered (26.8%), one of these being a monozygotic pregnancy. In total 129 frozen-thawed cycles have been achieved in 83 patients. One frozen-thawed embryo has been transferred in 46 cycles with a clinical pregnancy rate of 17.4%, and two embryos have been transferred in 83 cycles, with a clinical pregnancy rate of 37.3%. Up until now, 66 of 125 patients in our single embryo transfer programme have delivered or have on-going pregnancies, and 77 still have embryos frozen. The cumulative delivery rate per oocyte retrieval is 52.8% and the twin rate 7.6%. We conclude that elective single embryo transfer with a good cryopreservation programme results in very acceptable pregnancy rates with a low risk of twins. This is a cost-effective practice that substantially reduces all risks associated with multiple pregnancies and lowers the cost per delivery.     

提前复苏分裂速率较慢胚胎对妊娠率的影响

目的探讨冻融胚胎移植(FET)周期中,提前一日复苏冷冻前分裂速率较慢的胚胎对妊娠结局的影响。方法回顾性分析哈尔滨医科大学附属第一医院生殖中心2006年3月至2009年9月561例FET周期中,移植冷冻前分裂速率较慢胚胎的周期共88个。其中,33个周期为移植当日复苏胚胎,培养1-4h后移植。55个周期为移植前一日复苏胚胎,培养18-24h移植。比较两组胚胎移植后的妊娠率和种植率。结果移植当日复苏组与移植前一日复苏组妊娠率(9.1%,32.7%)与种植率(4.2%,15.5%)均有显著性差异(P﹤0.05);而患者平均年龄、移植前平均内膜厚度、胚胎复苏存活率及100%卵裂球存活率均无显著性差异(P﹥0.05)。结论对冷冻前分裂速率较慢胚胎提前一日复苏,可提高临床妊娠率和种植率。     

冻融胚胎和冻融囊胚对移植周期和分娩结局影响的比较

背景：自从1983年人类首例冷冻胚胎移植取得成功以来,胚胎冷冻技术已成为人类辅助生殖技术中重要组成部分。对选择冻融胚胎还是选择冻融囊胚移植,各地都有不少争议。 目的：比较解胚胎和囊胚经过低温保存解冻复苏后的分娩结局及新生儿状况。 方法：比较冻融胚胎移植周期1 273例和冷冻囊胚移植周期471例两组妊娠率、流产率、异位妊娠率、早产率、平均早产孕周、足月产率、平均足月产孕周、新生儿男女性别比例、出生体质量、出生缺陷等指标。 结果与结论：冻融囊胚解冻周期478例,移植周期471例(其中7例无囊胚移植取消),妊娠236例,分娩201例,分娩胎数251胎,男孩140个,女孩111个。冻融第3天胚胎解冻周期1 280例,移植周期1 273例(其中7例无胚胎移植取消),妊娠415例,分娩343例,分娩胎数431胎,男孩225个,女孩206个。冻融囊胚的妊娠率显著高于冻融胚胎妊娠率。冻融胚胎和囊胚的流产率、异位妊娠率、早产率、平均早产孕周、足月产率、平均足月产孕周、新生儿男女性别比例、出生体质量等差异无显著性意义。冻融胚胎和冻融囊胚移植出生缺陷并未明显增加。结果表明冻融囊胚与冻融胚胎的分娩结局及新生儿状况差异无显著性意义,但冻融囊胚的妊娠结局优于冻融胚胎的妊娠结局。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

卵裂期胚胎提前解冻培养过夜对冻融移植周期临床结局的影响

目的探讨玻璃化冻融周期中卵裂期胚胎当天解冻移植和提前1天解冻过夜培养后移植对妊娠结局的影响。方法选择武汉大学中南医院生殖医学中心2015年1月-2018年6月的414个冻融卵裂期胚胎移植周期进行回顾性分析。根据胚胎解冻和培养的时间点,分为当日解冻组(A组,207个周期)和提前解冻组(B组,207个周期);根据患者的年龄,A组B组又分别分成3个亚组,即年龄<30岁(A1,B1);年龄31~35岁(A2,B2)和年龄>35岁(A3,B3),比较各组间的种植率、临床妊娠率、活产率及流产率等的差异。结果A1组与B1组的临床妊娠率、种植率、活产率及流产率分别为47%vs 65.3%,30.3%vs 45.4%,36.4%vs 52.3%,15%vs 13.9%;A2组与B2组的临床妊娠率、种植率、活产率及流产率分别为54.8%vs 71.8%,38.2%vs 51.5%,46.6%vs 60.7%,21.9%vs17.6%;A3组与B3组的临床妊娠率、种植率、活产率及流产率分别为38.2%vs 52.9%,24.8%vs 37.3%,25%vs 36.8%,35.5%vs 29.2%;提前解冻在不同年龄组均可显著改善妊娠结局,差异均有统计学意义(P<0.05)。此外,无论是否提前解冻,年龄>35岁组的活产率均显著低于≤30岁组和31岁~35岁组(P<0.05),而妊娠率和种植率较其他两组亦呈现降低趋势,但差异无显著性。结论冻融卵裂期胚胎提前解冻培养后再进行移植能改善妊娠结局,并且随着女性年龄的增高,活产率均会随之下降。     

Endocrinology: Long-term evaluation of implantation of fresh and cryopreserved human embryos following ovarian stimulation with buserelin acetate-human menopausal gonadotrophin (HMG) or clomiphene citrate-HMG

This study is a long-term evaluation of the total pregnancypotential of cohorts of fresh and cryopreserved sibling embryosfrom in-vitro fertilization (TVF) cycles stimulated with eitherthe gonadotrophin-releasing hormone analogue buserelin (BUS)(long protocol) or clomiphene citrate (CC) both in combinationwith human menopausal gonadotrophin (HMG). Therefore a retrospectiveanalysis was performed on patients who entered the FVT programmebetween January 1986 and July 1987 and who had triple embryotransfer in the collection cycle. Significantly more fertilizedoocytes developed to good-quality embryos in the CC-HMG group(86.1%) than in the BUS-HMG group (80.8%). Transfer of the threemorphologically best-looking embryos was performed on day 2post-insemination in 106 CC-HMG and 80 BUS-HMG cycles. Supernumeraryembryos were cultured for a further 24 h and multicellular embryoswith up to 20% of fragments were frozen slowly with 1.5 M dimethylsulphoxideon day 3 post-insemination (162 embryos in CC-HMG cycles, 102embryos in BUS-HMG cycles). Outcome was measured by embryo survivalrate, embryo implantation rate and delivery rate in fresh andfrozen embryo transfers. Delivery rates were 31.3 and 21.7%per fresh embryo transfer in BUS-HMG and CC-HMG cycles respectively.Fresh embryo implantation rates were significantly higher incollection cycles stimulated with BUS-HMG (17.9%) than in cyclesstimulated with CC-HMG (113%). Implantation rates were significantlyenhanced in embryos transferred in excess of one in cycles leadingto pregnancy, perhaps indicative of higher embryo quality inBUS-HMG cycles. Almost all cryopreserved embryos have by nowbeen thawed, so the contribution of frozen embryos to overallpregnancy rates can be evaluated. Overall morphological survivalrates of frozen-thawed embryos were similar for 140 embryosfrom CC-HMG cycles (50%) and 100 embryos from BUS-HMG cycles(46%). The percentage of fully intact embryos was, however,significantly lower in the BUS-HMG group (19%) than in the CC-HMGgroup (39.5%). Delivery rates were significantly lower following30 transfers of frozen-thawed embryos from BUS-HMG-stimulatedcycles (3.3%) than following 42 transfers of frozen-thawed embryosfrom CC-HMG cycles (19.1%). Embryo implantation rates were lowerfor frozen-thawed embryos from BUS-HMG cycles (23%) than fromCC-HMG cycles (12.7%). Here we demonstrate that ovarian stimulationwith the long protocol BUS-HMG instead of the CC-HMG protocolled to higher embryo implantation rates in collection cyclesbut to lower intact embryo survival rates and to lower embryoimplantation rates for frozen sibling embryos. Despite the lowerimplantation rates with frozen embryos originating from theBUS-HMG protocol, there was no significant difference betweentotal delivery rate per transfer from cycles stimulated withCC-HMG (30.2%) compared with BUS-HMG (33.8%).     

冻融胚胎移植30周期分析

目的探讨冷冻胚胎复活情况及妊娠.方法对2001年9月～2003年9月在本中心实施体外授精胚胎移植失败,再次行冻融胚胎移植30周期28人进行回顾性分析.结果 30周期28人共冷冻胚胎150个,复活91个,复活率60.7%,妊娠8例,冷冻胚胎的妊娠率28.6%,周期妊娠率26.7%.结论冻融胚胎移植能增加一次取卵的总妊娠率,降低多胎率.     

The outcome of intracytoplasmic injection of fresh and cryopreserved epididymal spermatozoa from patients with obstructive azoospermia--a comparative study

The aim of our study was to compare the outcome of intracytoplasmic sperm injection (ICSI) with fresh and frozen-thawed epididymal spermatozoa retrieved by percutaneous epididymal sperm aspiration (PESA) or microepididymal sperm aspiration (MESA) from patients with obstructive azoospermia. A retrospective analysis of consecutive ICSI cycles was performed, comparing the outcome in 24 patients with obstructive azoospermia undergoing surgical sperm aspiration by MESA (7 cycles) or PESA (17 cycles). In 23 of 24 patients, excess spermatozoa were cryopreserved. Following thawing, 21 ICSI cycles were performed (11 cycles after MESA, 10 after PESA). No statistically significant differences were noted in all parameters examined in ICSI cycles with fresh or cryopreserved spermatozoa from the same patients. Comparing all ICSI cycles with fresh and frozen-thawed epididymal spermatozoa, the rates of two-pronuclear fertilization (56% versus 53%), embryo cleavage (90% versus 86%), implantation (10% versus 14%), clinical pregnancy per embryo transfer (32% versus 37%) and delivery/ongoing pregnancy rate (27% versus 26%) were not statistically different. The cumulative ongoing pregnancy rate per sperm retrieval procedure was 46%, respectively. We conclude that the clinical outcome of ICSI with fresh and frozen-thawed spermatozoa after retrieval by PESA was similar to that by MESA. Epididymal sperm cryopreservation in patients with obstructive azoospermia is feasible and efficient using a simple freezing protocol and should be offered to optimize the yield of pregnancies achieved following such procedures.      

冷冻方法对人卵裂期冷冻胚胎移植周期妊娠结局的影响

目的探讨慢速冷冻和玻璃化冷冻方法对人卵裂期冷冻胚胎移植周期妊娠结局的影响。方法回顾性分析2011年1月~2015年12月在北京大学第一医院进行卵裂期冷冻胚胎移植的1331个周期,包括慢速冷冻周期431个和玻璃化冷冻周期900个,比较两种不同冷冻方法的胚胎复苏率、完整胚胎率、临床妊娠率、种植率、流产率等各项指标,并分析卵裂球损伤对胚胎发育潜能的影响。结果玻璃化冷冻的胚胎复苏率(92.53%)、完整胚胎率(75.43%)、临床妊娠率(45.72%)、种植率(27.41%)高于慢速冷冻(76.93%、48.46%、39.52%、19.88%,P0.05);而流产率分别为12.20%、12.56%(P0.05);周期取消率分别为3.71%、1.33%(P0.05)。慢速冷冻移植0、1、2、3个无卵裂球损伤胚胎的临床妊娠率分别为:36.2%、37.7%、42.0%、44.3%(P0.05);玻璃化冷冻移植0、1、2、3个无卵裂球损伤胚胎的临床妊娠率分别为:20.5%、42.3%、48.8%、54.1%(P0.05)。结论玻璃化冷冻法更适合于人卵裂期胚胎冷冻保存,其冷冻胚胎移植周期的妊娠结局要优于慢速冷冻法;卵裂球损伤对玻璃化冷冻复苏胚胎的发育潜能影响较大。     

Frozen embryo transfers: implications of clinical and embryological factors on the pregnancy outcome

BACKGROUND: Frozen embryo transfers are characterized by impaired pregnancy outcome and increased incidence of pregnancy loss as compared with fresh IVF/ICSI embryo transfers. In this study, we performed a retrospective analysis of clinical and embryological factors that potentially influence the outcome of frozen embryo transfer. METHODS: We reviewed the outcome of 1242 frozen embryo transfers with respect to the age of the woman, the method of fertilization, embryo quality before and after freezing and the number of embryos transferred. RESULTS AND CONCLUSIONS: The pregnancy (positive hCG) and clinical pregnancy rates were 25.8 and 21.1%, respectively. A total of 107 (33.3%) of the 321 pregnancies identified by a positive hCG test miscarried either before (18.4%) or after (15%) the clinical recognition of gestational sac(s). The delivery rate for the frozen embryo transfers analysed was 17.2%. Our data revealed that the delivery rate after frozen embryo transfer was dependent on both the woman's age and the quality of embryos transferred, at the same time being unaffected by IVF/ICSI treatment. In addition, the increased woman's age at IVF/ICSI treatment was identified as the only parameter elevating the biochemical pregnancy rate, whereas the clinical abortion rate was found to be unrelated to the clinical or embryological parameters studied.     

Cryopreservation of biopsied embryos at the blastocyst stage

BACKGROUND: The availability of an efficient cryopreservation program is especially important in the case of embryos that have undergone blastomere biopsy for PGD. Unfortunately, the freezing/thawing of biopsied embryos has given disappointing results when performed at the cleavage stage. In this study, embryos diagnosed as normal after PGD were grown to the blastocyst stage, frozen and thawed for successive frozen embryo transfer. METHODS: A total of 34 patients performed a thawing cycle in which 47 blastocysts were thawed. The cryopreservation solutions were based on HEPES-buffered medium supplemented with human serum albumin (HSA), sucrose and 1,2-propanediol. The same protocol was applied to embryos from 88 IVF/ICSI patients, which underwent 92 thawing cycles with 150 thawed blastocysts. RESULTS: The survival rate was similar in the two groups (53% after PGD and 58% in IVF/ICSI cycles), as well as the cumulative pregnancy rate per patient (59% after PGD versus 47% in IVF/ICSI cycles), despite a higher maternal age and a lower proportion of embryos available for transfer or cryopreservation in the PGD group. CONCLUSIONS: Neither the survival rate nor the subsequent development and chances of implantation, differed between embryos frozen at the blastocyst stage following biopsy and those frozen intact.     

血LH峰与尿LH峰测定判断冻融胚胎移植时机的方法学比较

目的研究利用电化学发光免疫分析技术监测血LH板或利用尿LH板监测尿LH峰判断冻融胚胎移植时机的方法学比较。方法本中心由1999年5月至今共完成冻融胚胎移植67例,排除冻融胚胎移植周期中所移植的胚胎全部为部分卵裂球受损胚胎的周期后,将其中61例移植周期随机分成A、B两组,A组共12周期,通过使用尿LH板测定尿LH峰来判断冻融胚胎移植时机,B组共49个周期,通过电化学发光免疫分析技术测定血LH峰来判断冻融胚胎移植时机,对两组资料进行回顾性分析。结果两组患者平均冻融胚胎移植数目、冷冻前胚胎形态学评分及解冻后胚胎卵裂球存活程度等均无显著差异(P>0.05),冻融胚胎移植周期的子宫内膜厚度均大于8mm。利用尿LH峰测定判断冻融胚胎移植时机的12周期中,移植冻融胚胎37个,平均每周期移植胚胎3.1±0.4个,周期临床妊娠率33.3%(4/12)。利用血LH峰测定判断冻融胚胎移植时机行冻融胚胎移植的46例49个周期中,移植冻融胚胎137个,平均每周期移植胚胎2.8±0.1个,周期临床妊娠率63.3%(31/49),两组资料临床妊娠率有非常显著性差异(P<0.01)。结论利用电化学发光免疫分析技术监测血LH峰判断冻融胚胎移植时机比利用尿LH板监测尿LH峰判断冻融胚胎移植时机更为准确和灵敏,显著提高临床妊娠率。     

Selective transfer of cryopreserved human embryos with further cleavage after thawing increases delivery and implantation rates

We investigated whether further in-vitro culture of human multicellular embryos that survive cryopreservation can select the viable embryos for transfer. Embryos for cryopreservation were supernumerary multicellular embryos obtained after in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatments, with <20% of their volume filled with anucleate fragments. These had been cryopreserved using a slow-freezing and slow-thawing protocol with 1.5 M dimethylsulphoxide as the cryoprotectant. From the start of our cryopreservation programme until September 12, 1994, the thawing strategy was to thaw frozen embryos up to the exact number needed for transfer. Embryos for transfer were selected on the basis of their morphological appearance and embryo transfer to the patient was done on the day of thawing. From September 12, 1994 onwards we used a more selective thawing strategy where a cohort of up to a maximum of 12 frozen embryos per patient is thawed from which embryos of the best morphological quality, and which are furthest advanced in terms of cleavage after a 24 h in-vitro culture period in Menezo B2 medium, are selected. We took delivery rates, embryo implantation rates and birth rates into account to see if there is any difference between the following three types of transfers used: 187 transfers exclusively of embryos having continued to cleave after thawing, 107 mixed transfers of embryos with and without further cleavage and 53 transfers exclusively of embryos with no further cleavage. The overall outcome in terms of delivery rate and embryo implantation and birth rates were not different between the new and the earlier thawing policies (6.6, 5.2 and 3.6% versus 6.0, 4.1 and 2.7% respectively). Only when a distinction was made between transfers on the basis of the presence of embryos with further cleavage, did the advantage of selection on the basis of cleavage capacity become evident. Significantly higher delivery and embryo implantation and birth rates (11.2, 7.7 and 6.5% respectively) were recorded with transfers exclusively of embryos with further cleavage versus mixed transfers of embryos with and without further cleavage (1.9, 2.9 and 0.6% respectively). Fifty-three transfers exclusively of embryos with no further cleavage did not lead to any delivery. Our results demonstrate that selection of human multicellular embryos which survive cryopreservation and continue to cleave in vitro can significantly improve the delivery rate per transfer and the implantation rate per transferred embryo.      

Frozen-thawed transfer cycles: are they comparable with fresh?

Cryopreservation of zygotes and subsequent thaw and transfer is an established ART treatment. We assessed if success rates frozen-thawed (day 2) zygotes are comparable with the outcome in fresh cycles of treatment. We performed a prospective follow-up and analysis of all frozen (FZT) and fresh cycles of treatment during a 12 months period. One hundred and nineteen patients in the frozen-thawed and 652 in the fresh group had a transfer. The overall thaw-survival rate was 71.7%. Clinical pregnancy rates per thaw and transfer were respectively 15.1% and 21% in the frozen and 29.1% (per transfer) in the fresh group. Implantation rates in fresh and frozen cycles were 16% and 12.3% respectively. The pregnancy loss rate was higher in the FZT group (29% vs. 18.3%). Cryopreservation of good quality zygotes, after fresh transfer offers optimal success rates in subsequent frozen treatment. It also encourages consideration of elective single zygote transfers.