植入前遗传学诊断100个周期临床分析

目的 探讨染色体易位对早期胚胎发育的影响,以及植入前遗传学诊断(PGD)技术的诊断效率和可行性.方法 回顾性分析PGD中23个罗伯逊(罗氏)易位周期、19个平衡易位周期(染色体易位组),以及58个α地中海贫血周期(地贫组)共100个周期中的胚胎发育情况、PGD的诊断效率以及临床结局.结果 染色体易位组中有354个胚胎进行PGD,321(90.7%)个胚胎有荧光原位杂交(FISH)结果,其中罗氏易位者中正常和(或)平衡易位胚胎占38.3%(64/167),显著高于平衡易位者的20.8%(32/154).地贫组有537个胚胎进行PGD,单个卵裂球的扩增效率为82.5%(443/537),诊断出正常纯合子140个、杂合子112个、异常纯合子155个、另36个诊断结果不明确,总体诊断效率为75.8%(407/537).染色体易位组中,取卵后第3天卵裂球数≥7的胚胎中,正常和(或)平衡易位发生率(34.4%,77/224)显著高于卵裂球数＜7的胚胎(19.6%,19/97),在取卵后第4天,正常和(或)平衡易位胚胎的细胞融合率为59.4%(57/96),显著高于染色体不平衡胚胎的34.2%(77/225).染色体易位组共在37个周期移植了75个胚胎,获得10例临床妊娠,临床妊娠率27.0%(10/37).地贫组共在58个周期移植了170个胚胎,获得25例临床妊娠,临床妊娠率为43.1%(25/58).结论 PGD技术可有效为染色体易位和地中海贫血基因携带者提供优生选择.染色体易位可能对着床前胚胎的发育有一定的影响.

Abstract：

Objective To investigate influence of chromosomal translocations on early embryo development and to evaluate the efficacy and feasibility of preimplantation genetic diagnosis (PGD)techniques through clinical analysis on PGD cycles. Methods Embryo development, efficacy of PGD and clinical outcome of 100 cycles were studied retrospectively, including 23 cycles with Robertsonian translocations, 19 cycles with reciprocal translocations, and 58 cycles for α-Thalassaemia. Results Among 354 embryos biopsied by PGD for translocations, 321 (90. 7% ) presented fluorescence in situ hybridization (FISH) results. The rate of normal/balanced embryos in the Robertsonian translocation was 38. 3% (64/167),which was significantly higher than 20. 8% (32/154) in the reciprocal translocation group. Amplification was achieved in 443 blastomeres from 537 embryos in Thalassaemia group, which given to an amplification efficiency rate of 82. 5% ( 443/537 ). Totally, 140 normal homozygous, 112 heterozygotes and 155 affected homozygous embryos were identified, while 36 embryos had uncertain result. The successful diagnostic rate was 75.8% (407/537). After 3 days in the translocation groups, the rate of normal and/or balanced translocations in biopsed embryos with ≥7 cells was 34. 4% (77/224), which was significantly higher than 19. 6% ( 19/97 ) of biopsed embryos with ＜ 7 cells. After 4 days, the compaction rate in normal/balanced embryos was 59.4% ( 57/96 ), which was significantly higher than 34. 2% ( 77/225 ) in imbalanced embryos significantly. Seventy-five embryos transferred in 37 cycles with translocations group led to clinical pregnancy rate of 27.0% (10/37), and 170 embryos transferred in 58 cycles with Thalassaemia got a clinical pregnancy rate of 43. 1% ( 25/58 ) . Conclusions PGD can provide management efficiently for both chromosome translocations and Thalassaemia. Translocations might have slightly negative impact on embryo development before implantation.     

121个染色体平衡易位携带者PGD周期COH的卵巢反应性分析

目的:探讨常染色体平衡易位对女性携带者控制性超促排卵(COH)中卵巢反应性的影响。方法:回顾分析于我院行胚胎植入前遗传学诊断(PGD)的109对常染色体平衡易位夫妇,共121个周期,其中夫妇中仅女方为平衡易位携带者56例(63个周期,研究组),包括罗伯逊易位携带者23例(27个周期),相互易位携带者33例(36个周期);夫妇中仅男方为平衡易位携带者53例(58个周期,对照组),包括罗伯逊易位携带者30例(32个周期),相互易位携带者23例(26个周期)。分析COH过程中,研究组和对照组的女方卵巢反应性指标和妊娠结局。结果:两组的女方年龄、体重指数(BMI)、基础内分泌及窦卵泡数(AFC)均无显著差异(P0.05)。两组的卵巢反应性指标,包括Gn总量、HCG注射日E2水平、获卵数、D3胚胎数、可移植胚胎数及移植胚胎数,以及移植周期临床妊娠率、早期流产率及种植率均无显著差异(P0.05)。单独就罗伯逊易位携带者或相互易位携带者而言,两组的各指标均无显著差异。排除可能影响COH卵巢反应性的女方因素,研究组与对照组的各指标均无显著差异。结论:染色体平衡易位,包括罗伯逊易位或相互易位并不影响COH中的卵巢反应性。应将染色体平衡易位女性携带者视为正常卵巢反应性,采用合适剂量的促性腺激素进行控制性促排卵。     

荧光原位杂交技术不同方案用于染色体易位携带者胚胎植入前遗传学诊断的效率比较

目的 探讨荧光原位杂交(FISH)技术不同方案用于染色体易位携带者胚胎植入前遗传学诊断(PGD)的效率.方法 根据FISH检测方案的不同进行分组:采用全染色体涂抹探针对染色体易位携带者8个周期的109个卵母细胞第一极体进行诊断(A组),采用联合端粒和着丝粒探针对染色体易位携带者29个周期的357个卵裂球进行诊断(B组),比较两组的活检成功率、固定时细胞丢失率、无核细胞数等.结果 A组的109个卵母细胞中72个受精,受精率为66.1%(72/109),B组的357个卵裂球中304个受精,受精率为85.2%(304/357),A组的受精率显著低于B组,差异有统计学意义(P<0.05).固定时细胞丢失率A组为9.6%(12/104),B组为1.6%(4/252),两组比较,差异也有统计学意义(P<0.05).杂交后核的无信号率A组为11.2%(10/89),B组为3.0%(7/233),两组比较,差异有统计学意义(P<0.05).A组的诊断率为72.5%(79/109),显著低于B组的89.8%(230/256),差异有统计学意义(P<0.05).A组的临床妊娠率和胚胎植入率分别为3/7和22.2%(4/18),均高于B组的30.4%(7/23)和15.7%(8/51),但差异均无统计学意义(P>0.05).结论 FISH两种方案均可有效地进行染色体平衡易位的PGD,卵裂球PGD的诊断效率更高.     

常染色体平衡易位携带者控制性促排卵周期卵巢反应性分析

目的探讨常染色体平衡易位及类型对胚胎植入前遗传学诊断(PGD)周期控制性促排卵(COS)中卵巢反应性的影响。方法回顾性分析379对染色体平衡易位夫妇行PGD的426个COS周期,其中男方正常女方为平衡易位携带者182个周期(研究组,A组),包括罗氏易位44个周期(A1组),相互易位138个周期(A2组);女方正常男方为平衡易位携带者244个周期(对照组,B组),包括罗氏易位65个周期(B1组),相互易位179个周期(B2组)。比较各组间COS中女方卵巢反应性指标。结果研究组与对照组间年龄、体质量指数(BMI)、基础内分泌(FSH、E2、LH)、窦卵泡数(AFC)、促性腺激素(Gn)用量和使用时间、第2日和第3日胚胎数、囊胚数、卵子成熟率、囊胚形成率等均无统计学差异(P0.05);A组h CG注射日E2水平、正常信号囊胚数[(5 469.8±2 365.1)ng/L,1.4±1.4]均显著低于B组[(6 033.3±2 587.5)ng/L,1.8±1.8](P0.05),A组取卵数、MII卵子数、形成囊胚数均低于B组,但是无统计学差异(P0.05);A1组h CG注射日E2水平、正常信号囊胚数[(5 573.2±2 146.1)ng/L,1.5±1.5]显著低于B1组[(6 565.0±2 961.1)ng/L,2.8±2.2](P0.05);A2组取卵数(14.6±6.6)显著低于B2组(16.5±6.7)(P0.05)。结论 (1)女方常染色体平衡易位可能影响COS中卵巢反应性;(2)女方罗氏易位形成平衡或正常胚胎几率低于男方罗氏易位者。     

染色体平衡易位携带者妊娠风险及妊娠结局的研究

目的 探讨染色体平衡易位携带者的妊娠风险及其妊娠结局.方法 194例染色体平衡易位携带者,根据平衡易位种类分成相互易位（135例）、非同源罗伯逊易位（52例）、同源罗伯逊易位（7例）3组.调查携带者生育史并随访诊断平衡易位后的妊娠情况,比较各组自然流产、先天缺陷及正常（或）平衡易位后代概率.结果 （1）194对夫妇共妊娠503例次,其中自然流产411例次（81.7%,411/503）;产前诊断胎儿异常而终止妊娠16例次（3.2%,16/503）;活产缺陷儿36例次（7.2%,36/503）;正常（或）平衡易位后代40例次（8.0%,40/503）.（2）相互易位、非同源罗伯逊易位、同源罗伯逊易位3组,活产缺陷儿比率分别为5.7%（20/350）、10.9%（14/128）、8.0%（2/25）,3组间相互比较,差异有统计学意义（P＜0.05）;3组正常（或）平衡易位后代比率分别为6.6%（23/350）、13.3%（17/128）、0,3组间相互比较,差异有统计学意义（P＜0.05）;而3组自然流产及产前诊断胎儿异常终止妊娠比率比较,差异无统计学意义（P＞0.05）.（3）52例次先天缺陷中活产36例次（69%）,经产前诊断确诊后引产16例次（31%）.27例次先天缺陷获得细胞遗传学诊断,唐氏综合征发生率为59%（16/27）.（4）相互易位组和非同源罗伯逊易位组共有39对夫妇得到40个正常（或）平衡易位后代,同源罗伯逊易位组无正常（或）平衡易位后代.40个正常（或）平衡易位后代中26个获得产前细胞遗传学诊断,正常核型6个（23%）,平衡易位核型20个（77%）.结论 染色体平衡易位携带者自然妊娠风险大,尤其同源罗伯逊易位携带者难以获得染色体正常（或）平衡易位的后代.     

胚胎植入前遗传学诊断10个周期的临床分析

目的:初步探讨使用荧光原位杂交(FISH)方法对染色体异常患者进行胚胎植入前遗传学诊断(PGD)的临床意义。方法:7对不孕夫妇采用长方案控制性超排和卵胞浆内单精子注射,受精后d3胚胎活检、卵裂球固定和FISH,d4或d5择合适胚胎移植。结果:7对夫妇共进行10个PGD周期。获卵251个,可供活检胚胎133个,活检卵裂球207个,胚胎活检成功率为96.2%(128/133)。128个成功活检胚胎的197个卵裂球,其单细胞固定率为93.9%(185/197),FISH信号率为90.8%(168/185)。10个周期共移植22个胚胎,3例获得妊娠,并均足月分娩健康婴儿,其中1例孕妇平衡易位携带者于孕中期时,羊水核型分析为平衡易位携带者。结论:应用FISH方法进行PGD,是遗传病高危夫妇预防流产和染色体异常患儿出生的有效手段。     

短串联重复序列在染色体罗氏易位植入前遗传学诊断的应用

目的:采用多重置换扩增(MDA)结合短串联重复序列(STR)建立一种基于PCR技术诊断染色体罗氏易位的植入前遗传学诊断(PGD)方法。方法:选择位于易位染色体上的STR位点,对家系采用荧光PCR进行分析,选择有多态性的位点,再采用MDA对单细胞进行全基因组扩增,根据家系分析的结果,对具有多态性的STR位点进行分析诊断。结果:对3个家系进行了4个取卵周期(3个PGD周期),每个家系分别采用7~15个具有多态性的STR位点进行分析,共对24个胚胎进行诊断。PGD的诊断效率为95.8%(23/24),平衡胚胎占52.2%(12/23),异常胚胎占47.8%(11/23),共移植了6个胚胎,获得2例临床妊娠,临床妊娠率为66.7%(2/3),出生了2个健康婴儿,染色体核型均正常。结论:采用依赖于STR的PCR分析法可以用于染色体罗氏易位的PGD。     

平衡易位携带者孕中期产前诊断结果分析

目的:探讨平衡易位携带者孕中期胎儿产前诊断结果及妊娠结局,为平衡易位携带者遗传咨询及生育指导提供科学依据。方法:选择2015年1月至2016年12月夫妻之一为平衡易位携带者65例,于妊娠18~24周在我院行羊水染色体核型检查,并针对检测结果进行分析。结果:65例平衡易位携带者,28例(43.1%)胎儿染色体核型正常,25例(38.5%)胎儿为平衡易位携带者,12例(18.4%)胎儿为不平衡易位患者。其中总妊娠次数为187次,早期流产总次数为122次(65.2%);妊娠活产53次(28.3%),此次妊娠活产率81.5%(53/65);引产12次(6.4%)。13号与14号染色体发生相互易位的几率最高(16.2%,19.2%),其生育不平衡胎儿的几率分别为4.8%和12.0%。结论:平衡易位携带者夫妇其早期流产发生率较高,妊娠到孕中期后获得染色体正常后代和平衡易位携带者后代的几率较高,选择自然妊娠并进行产前诊断来获取健康后代是完全可行的。不同染色体发生易位其生育不平衡后代几率不同。     

染色体易位-胚胎植入前诊断的研究进展

染色体易位携带者有较高的发生不良妊娠结局的风险,主要源自高概率的非均衡配子。对于染色体易位的携带者,进行胚胎植入前遗传学诊断(preimplantation genetic diagnosis,PGD)可以改善妊娠结局。目前,临床应用的非平衡易位诊断的方法主要有比较基因组杂交微阵列(comparative genomic hybridization array,array CGH)、单核苷酸多态性微阵列(single nucleotide polymorphism array,SNP array)和二代测序(next generation sequencing,NGS);荧光原位杂交(fluorescence in situ hybridization,FISH),能够区分平衡易位和正常胚胎,可能实现的技术有NGS。此外,平衡易位的诊断是否有必要开展尚存在争议。     

女性罗氏易位携带者辅助生育治疗5例临床分析

目的:探讨应用极体分析和分裂球分析法对反复流产的女性罗氏易位携带者进行着床前遗传学诊断(PGD)的临床策略。方法:采用荧光原位杂交(FISH)技术,对5例患者用全染色体涂抹探针检测第一极体和用特异位点探针检测分裂球中相应染色体的荧光信号。5例女性罗氏易位携带者的外周血淋巴细胞染色体核型分别为:45,XX,der (13;14)(q10;q10)3例,45,XX,der(14;21)(q10;q10)、45,XX,der(21;22)(q10;q10)各1例。结果:5例患者中4例获得妊娠并分娩,其中2例经分裂球分析后妊娠,出生3个婴儿:2个正常核型,1个罗氏易位携带者;1例经极体分析诊断后分娩一正常男婴;另1例极体分析未明确诊断又行分裂球分析选择胚胎移植后,出生1个罗氏易位携带者后代。结论:(1)女性罗氏易位携带者PGD应首选极体分析,争取避免携带者出生;(2)极体分析未能得到诊断的胚胎可在分裂球期再次PGD。     

Embryo development characteristics in Robertsonian and reciprocal translocations: a comparison of results with non-translocation cases

The effect of translocations on embryo development was evaluated and results were compared in terms of embryo development with those of embryos obtained from standard intracytoplasmic sperm injection (ICSI) cycles. In 23 translocation carriers with 34 cycles, fertilization, pronuclear morphology scoring (PMS), developmental arrest, cleavage and blastocyst formation were evaluated and compared with embryos obtained from non-translocation cases undergoing ICSI (n = 98 cycles). In 28 cycles, preimplantation genetic diagnosis (PGD) was performed on prezygotes (first and second polar body biopsy for female carriers; n = 3) or on embryos having seven or more blastomeres (blastomere biopsy; n = 25). In six cycles for four couples, probes for translocated chromosomes were not available, so PGD could not be performed. Overall, in translocation cases, a lower fertilization rate, a higher rate of retarded embryo development, and a lower rate of blastocyst formation were observed compared with embryos of non-translocation cases. Fluorescence in-situ hybridization (FISH) analysis showed a 70.9% abnormality rate for reciprocal translocations and 55.0% for Robertsonian translocations respectively. In cases with Robertsonian and reciprocal translocation carriers, the probability of poor embryo development, which may be a result of high segregation abnormalities, may negatively affect the outcome of assisted reproductive techniques. This poor prognosis should also be considered when genetic counselling for translocation is given.     

胚胎染色体非整倍体筛查用于平衡易位携带者植入前的遗传学诊断

目的 交信号和1个Y染色体杂交信号者,则诊断为整倍体胚胎;异常杂交信号的胚胎则诊断为非整倍体胚胎.结果 (1)11个平衡易位的PGD周期中,选出杂交信号完整的130个细胞核进行分析,FISH共分析了937个荧光杂交信号,其中整倍体细胞核38个,共有304个杂交信号;其余92个为非整倍体细胞核.(2)在92个非整倍体细胞核中,Ⅰ、Ⅱ及Ⅲ级胚胎的比例分别为20个(22%)、36个(39%)及36个(39%);38个整倍体细胞核中,Ⅰ、Ⅱ及Ⅲ级胚胎的比例分别为13个(34%)、17个(45%)及8个(21%),两者的Ⅰ、Ⅱ及Ⅲ级胚胎数分别比较,差异均无统计学意义(P＞0.05).虽然染色体整倍体率在不同级别胚胎中的分布比较,差异均无统计学意义(P＞0.05),但优质胚胎(Ⅰ级+Ⅱ级)中非整倍体率仍为60%(56/92).(3)平衡胚胎来源的卵裂球细胞核整倍体率(71.4%,30/42)明显高于非平衡胚胎来源的卵裂球细胞核整倍体率(9.1%,8/88),两者比较,差异有统计学意义(P＜0.05).平衡胚胎来源的卵裂球细胞核非整倍体率(包括三体、单体、复杂非整倍体、单倍体、多倍体)明显低于非平衡胚胎来源的卵裂球细胞核非整倍体率(P＜0.05).结论 平衡易位携带者的胚胎中有较高的非整倍体率,因此,胚胎非整倍体筛查在平衡易位携带者的PGD中有重要价值和临床意义.

Abstract：

Objective To determine the importance of aneuploidy screening in preimplantation genetic diagnosis for the couples of chromosome translocation carriers. Methods To perform 11 prenatal genetic disgnosis (PGD) cycles for 7 couples of chromosome translocation carriers from January 2006 to March 2009 in the Reproductive Medical Center, First Affiliated Hospital of Zhengzhou University. To re-analyze the well-fixed, non-multinuclear and non-debris nuclei using the probes of LSI 13, 18, 21,CEPX, CEPY to detect the aneuploidy rate which come from the PGD cycles of the couples of chromosome translocation carriers. The euploid embryo was defined as two fluorescence in situ hybridization (FISH)signals of LSI 13, 18, 21 respectively and two signals of CEPX, or one signal of CEPX and one signal of CEPY. The other abnormal signals were defined as aneuploid embryo. Results (1) A tolal of 130 nuclei from 11 PGD cycles got the integrated re-FISH signals. Nine hundred and thirty-seven FISH signals were analysized, including 304 signals from 38 euploid nuclei and the others from 92 aneuploid nuclei. (2) The number of the aneuploid nuclei from grade Ⅰ , Ⅱ and Ⅲ embryo was 20 (22%), 36(39%), and 36(39%). The number of the euploid nuclei from grade Ⅰ , Ⅱ and Ⅲ embryo was 13(34%), 17(45%),and 8(21%). There was no significant difference of aneupioidy rate between the embryos form different grades (P＞0.05). However, the rate of aneuploid nucleus from good quality embryos (grade Ⅰ + grade Ⅱ) was 60% (59/92). (3) The euploidy rate was 71.4% (30/42) from balanced embryos, while 9.1%(8/88)from unbalanced embryos. There was significant difference between them (x2=53.4, P＜0.05).The rate of aneuploidy from balanced embryos was lower than those from unbalanced embryos (P＜0.05).Conclusions Since higher rate of aneuploidy was detected in embryos of the couples of chromosome translocation carriers. It is advisable to recommend the FISH re-analysis for aneuploidy screening to preimplantation genetic diagnosis for the couples of chromosome translocation carriers.     

Highly abnormal cleavage divisions in preimplantation embryos from translocation carriers

We have developed preimplantation genetic diagnosis (PGD) for carriers of chromosomal abnormalities using fluorescent in situ hybridisation (FISH). Here we present the detailed analysis of 64 biopsied, normally developing embryos obtained from four Robertsonian and three reciprocal translocation carriers in 11 treatment cycles of which four resulted in normal pregnancies (three simplex, one duplex). In order to investigate the degree of mosaicism and segregation mode in the embryos, the primary analysis of the biopsied cells was extended with the analysis of all cells from the non-transferred embryos. The analysis also included a second hybridisation with two additional probes, not involved in the translocation (chromosomes 1 and 9), in order to investigate the overall degree of mosaicism. Seventeen out of 64 analysed embryos were balanced for the chromosomes involved in the translocation and 14 of these were transferred. Forty-seven out of 64 embryos (73%) were mosaic regarding the chromosomes involved in the translocation and alternate segregation mode was the most common mode of segregation. Moreover, we have found a higher degree of mosaicism for the chromosomes involved in translocations as compared to control chromosomes. This difference was more pronounced for the embryos from reciprocal translocation carriers. The results, mechanisms, significance and implications of our findings are discussed.     

Natural selection between day 3 and day 5/6 PGD embryos in couples with reciprocal or Robertsonian translocations

Purpose

For translocation carriers, preimplantation genetic diagnosis (PGD) provides the opportunity to distinguish between normal/balanced and unbalanced embryos prior to implantation and, as such, increases the likelihood of a successful ongoing pregnancy. The data presented here compares autosomal reciprocal and Robertsonian translocation segregation patterns in day 3 versus day 5/6 IVF-PGD embryos to determine if there is a difference in the chromosome segregation patterns observed at these developmental time points.

Methods

A retrospective analysis on PGD translocation carriers at Monash IVF was performed. Segregation patterns were compared between day 3 and day 5/6 embryos to ascertain whether selection against malsegregants exists.

Results

For reciprocal translocations, 1649 day 3 embryos (139 translocations) from 144 couples and 128 day 5/6 embryos (59 translocations) from 60 couples were analysed. Day 3 segregation analysis showed that 22.3% of embryos were normal/balanced (consistent with 2:2 alternate segregation) and 77.7% were unbalanced (malsegregation). Day 5/6 segregation analysis showed that 53.1% of embryos were normal/balanced and 46.9% were unbalanced. For Robertsonian translocations, 847 day 3 embryos (8 translocations) from 54 couples and 193 day 5/6 embryos (6 translocations) from 31 couples were analysed. Day 3 segregation analysis showed that 38.7% of embryos were normal/balanced (consistent with 2:1 alternate segregation) and 61.3% were unbalanced. Day 5/6 segregation analysis showed that 74.1% of embryos were normal/balanced and 25.9% were unbalanced.

Conclusions

This data demonstrates an increase in the proportion of genetically normal/balanced embryos at day 5/6 of development. This suggests a strong natural selection process between day 3 and day 5/6 in favour of normal/balanced embryos. These findings support performing PGD testing on day 5/6 of embryo development.

     

Analysis of chromosome abnormalities in sperm and embryos from two 45,XY,t(13;14)(q10;q10) carriers

Robertsonian translocation t(13q14q) is studied in sperm and embryos of two couples undergoing preimplantation genetic diagnosis (PGD) in which both males are carriers of the translocation. It is already known that the chances of achieving pregnancy for a translocation carrier are directly linked to the number of normal or balanced embryos available for replacement. In our work it was found that the frequency of balanced spermatozoa was almost identical in both patients (74 and 77%), and after PGD, the frequencies of abnormal embryos caused by the translocation were also similar. Sperm chromosome analysis in translocation carriers can provide a reasonable basis for estimating a baseline of chromosome abnormalities to be found in embryos during an assisted reproductive cycle. However, individual factors not linked to the translocation can also produce other chromosome abnormalities (mosaicism, haploidy, polyploidy) and may compromise the chances of achieving a viable pregnancy.     

Clinical outcome of treatment cycles using preimplantation genetic diagnosis for structural chromosomal abnormalities

OBJECTIVES: To explore oocyte recovery, embryo quality, the number of transferable embryos and pregnancy rate after preimplantation genetic diagnosis (PGD) in patients with structural chromosomal aberrations. METHODS: PGD was performed in seven couples with Robertsonian translocations (Rob), eight couples with reciprocal translocations (Rec), two couples with inversions and one couple with a deletion. A total of 43 treatment cycles were carried out. RESULTS: A total of 14.2 oocytes per cycle were retrieved. Fertilisation and cleavage rates were 63% and 58%, respectively. Of the biopsied embryos 20% were transferable. Comparison of the Rob and Rec group revealed no significant differences in number of oocytes, fertilisation or cleavage rates. The number of transferable embryos after biopsy was significantly higher in the Rob group than in the Rec group. When embryo transfer (ET) was performed the pregnancy rate did not differ between the Rob and the Rec groups. Twenty-eight embryo transfers (one or two embryos) were carried out leading to eight clinical pregnancies (29% per ET): two twins, four singletons, one miscarriage and one ectopic pregnancy. All the children are carriers of balanced chromosomal aberrations. CONCLUSION: An acceptable pregnancy rate can be achieved among couples with structural chromosomal abnormalities.     

Efficacy and clinical outcome of preimplantation genetic diagnosis using FISH for couples of reciprocal and Robertsonian translocations: the Korean experience

OBJECTIVE: To evaluate the efficacy and clinical outcome of preimplantation genetic diagnosis (PGD) using fluorescence in situ hybridization (FISH) for couples with chromosomal translocations. METHODS: PGD using FISH was performed in 59 cycles of 43 couples with reciprocal translocations, and 11 cycles of 6 couples with Robertsonian translocations. The diagnostic and clinical data were reviewed in a series of 70 treatment cycles of 49 couples from January 2001 to June 2002 at Samsung Cheil Hospital, Korea. RESULTS: A total of 1408 oocytes were retrieved, and 938 (81.7%) out of 1148 matured oocytes were fertilized by intracytoplasmic sperm injection (ICSI). Single blastomere biopsy and FISH analysis were successfully carried out in 99.3% (890/896) and 94.4% (840/890), respectively. Among 193 normal or balanced embryos, 169 embryos were transferred in 64 cycles (91.4% per started cycle). Twenty clinical pregnancies including two ectopic pregnancies and three spontaneous miscarriages (28.6% per started cycle, 31.3% per transfer cycle, 40.8% per couple) were established. Of the three spontaneous miscarriages, one was karyotyped as normal, one had an unbalanced arrangement and one was tetraploid. One case of preterm twin delivery occurred and 16 healthy babies were delivered in 12 single and 2 twin pregnancies. CONCLUSION: The clinical outcome was successful in 28.6% (14/49) of the treated couples with translocations after PGD. The spontaneous abortion rate was significantly reduced from 95.8% (69/72) to 16.7% (3/18) in these couples.     

Preimplantation genetic diagnosis by fluorescence in situ hybridization of reciprocal and Robertsonian translocations

ObjectiveThe presence of reciprocal and Robertsonian chromosomal rearrangement is often related to recurrent miscarriage. Using preimplantation genetic diagnosis, the abortion rate can be decreased. Cases treated at our center were reviewed.Materials and methodsA retrospective analysis for either Robertsonian or reciprocal translocations was performed on all completed cycles of preimplantation genetic diagnosis at our center since the first reported case in 2004 until the end of 2010. Day 3 embryo biopsies were carried out, and the biopsied cell was checked by fluorescent in situ hybridization using relevant informative probes. Embryos with a normal or balanced translocation karyotype were transferred on Day 4.ResultsThirty-eight preimplantation genetic diagnosis cycles involving 17 couples were completed. A total of 450 (82.6%) of the total oocytes were MII oocytes, and 158 (60.0%) of the two-pronuclei embryos were biopsied. In 41.4% of the fluorescent in situ hybridization analyses, the results were either normal or balanced. Embryos were transferred back after 21 cycles. Three babies were born from Robertsonian translocation carriers and another two from reciprocal translocation carriers. The miscarriage rate was 0%. Among the reciprocal translocation group, the live delivery rate was 8.3% per ovum pick-up cycle and 18.2% per embryo transfer cycle. Among the Robertsonian translocation group, the live delivery rate was 14.3% per ovum pick-up cycle and 20.0% per embryo transfer cycle.ConclusionThere is a trend whereby the outcome for Robertsonian translocation group carriers is better than that for reciprocal translocation group carriers. Aneuploidy screening may possibly be added in order to improve the outcome, especially for individuals with an advanced maternal age. The emergence of an array-based technology should help improve this type of analysis.     

Two different microarray technologies for preimplantation genetic diagnosis and screening,due to reciprocal translocation imbalances,demonstrate equivalent euploidy and clinical pregnancy rates

Purpose

To compare single nucleotide polymorphism (SNP) and comparative genomic hybridization (aCGH) microarray platforms to evaluate embryos for parental translocation imbalances and aneuploidy.

Methods

A retrospective review of preimplantation genetic diagnosis and screening (PGD/PGS) results of 498 embryos from 63 couples undergoing 75 in vitro fertilization cycles due to parental carriers of a reciprocal translocation.

Results

There was no significant difference between SNP and aCGH microarrays when comparing the prevalence of embryos that were euploid with no translocation imbalance, euploidy with a parental translocation imbalance or aneuploid with or without the parental chromosome imbalance. The clinical pregnancy rates were also equivalent for SNP (60 %) versus aCGH (65 %) microarrays. Of 498 diagnosed embryos, 45 % (226/498) were chromosomally normal without translocation errors or aneuploidy, 22 % (112/498) were euploid but had a parentally derived unbalanced chromosomal segregant, 8 % (42/498) harbored both a translocation imbalance and aneuploidy and 24 % (118/498) of embryos were genetically balanced for the parental reciprocal translocation but were aneuploid for other chromosomes. The overall clinical pregnancy rate per IVF cycle following SNP or aCGH microarray analysis was 61 % and was higher if the biopsy was done on blastocysts (65 %) versus cleavage stage embryos (59 %), although not statistically significant.

Conclusions

SNP or aCGH microarray technologies demonstrate equivalent clinical findings that maximize the pregnancy potential in patients with known parental reciprocal chromosomal translocations.