染色体易位的植入前遗传学诊断

目的 观察染色体平衡易位和罗伯逊(罗氏)易位基因携带者夫妇进行植入前遗传学诊断(PGD)后的胚胎染色体遗传特征和胚胎着床、妊娠情况,探讨PGD在染色体易位基因携带者夫妇实现正常生育中的意义.方法 用荧光原位杂交(FISH)技术对36对夫妇的胚胎进行PGD,其中14例为染色体平衡易位(平衡易位组),22例为染色体罗氏易位(罗氏易位组),并对诊断结果和胚胎着床、妊娠情况进行分析.结果 36例患者共活检胚胎253个,成功诊断胚胎225个,成功率为88.9%(225/253),获得可供移植的正常或平衡的胚胎共58个.平衡易位组和罗氏易位组PGD后胚胎着床率分别为36%(5/14)和14%(6/44),临床妊娠率分别为4/9和26%(5/19).结论 PGD可有效诊断胚胎染色体平衡易位和罗氏易位,避免反复流产和不必要的非意愿性终止妊娠,并获得理想的胚胎着床率和临床妊娠率.     

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.     

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。     

原核形态、卵裂胚发育与染色体异常关系的研究

目的 探讨原核形态评分(原核评分)、卵裂胚发育与染色体异常的关系.方法 2005年9月至2006年3月在广州医学院第三附属医院对需要行胚胎植入前诊断(PGD)的7例患者,于受精后第3天,应用荧光原位杂交(FISH)方法 .选用13、18、21、X、Y 5种染色体探针筛查这些病人种植前胚胎的非整倍体,同时分析原核评分、胚胎发育与染色体异常的关系.结果 7例患者各行PGD 1个周期,共获得73个胚胎;根据原核评分将所有胚胎分成A、B两组.原核评分≥14分的胚胎为A组,共49个;＜14分者为B组,24个;在A组中,优质胚胎比例为46.9%(23/49).显著高于B组的20.8%(5/24),P＜0.05;对52个胚胎进行活检,51个胚胎有FISH诊断结果 ;在有FISH诊断结果 、原核评分≥14分的胚胎中,正常胚胎的比例为51.4%(19/37),显著高于评分＜14分胚胎的21.4%(3/14),P＜0.05;优质胚胎中,正常胚胎的比例为55.6%(15/27),显著高于非优质胚胎的29.2%(7/24),P＜0.05.原核评分≥14分的优质胚胎中,染色体正常胚胎的比例为70.0%(14/20),高于优质胚胎的55.6%,但差异无统计学意义(P＞0.05).结论 评分高的原核有更大的机会发育成优质胚胎和染色体正常的胚胎,优质胚胎中染色体正常胚胎的比例高于非优质胚胎.     

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。     

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.     

染色体罗伯逊易位女性携带者对控制性超排卵的卵巢反应

目的:初步探讨罗伯逊易位对控制性超促排卵(COH)中卵巢反应性的影响。方法:回顾性分析12个周期针对罗伯逊易位不孕夫妇行胚胎植入前遗传学诊断(PGD)的COH方案,其中女性罗伯逊易位携带者(研究组)5个周期,男性罗伯逊易位携带者(对照组)7个周期。比较分析患者年龄、体质量指数(BMI)、基础内分泌及COH中降调节天数、Gn使用天数、Gn用量、hCG注射日E2值、获卵数、2PN受精率、2PN卵裂率、移植胚胎数等。结果:年龄、BMI、基础内分泌及COH中降调节天数、Gn使用天数、2PN受精率、2PN卵裂率、移植胚胎数及获卵数组间无统计学差异,但研究组的Gn用量(3 128.6±891.3 IU)明显高于对照组(1 810.0±630.9 IU)(P<0.05);研究组hCG注射日E2值为3 233.8±1 938.2 pg/ml,明显低于对照组的8 143.6±1 926.3 pg/ml(P<0.05)。结论:染色体罗伯逊易位影响卵巢对COH的反应性。     

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。     

常规体外受精-胚胎移植周期中改行未成熟卵母细胞体外培养的临床研究

目的 探讨常规体外受精-胚胎移植(IVF-ET)周期中改行未成熟卵母细胞体外培养(IVM)的临床疗效果.方法 回顾性分析2008年1月至2009年6月在温州医学院附属第一医院生殖医学中心行常规IVF治疗,在促排卵5-7 d后,双侧卵泡数目≥20个,或用药8-13 d后,卵泡发育缓慢且两侧卵泡数日≥15个,平均最大卵泡直径≤12 mm的155个周期,根据患者意愿,即刻停药取卵、改行IVM治疗60个周期(A组),继续按照IVF常规治疗95个周期(B组).比较两组促性腺激素(Gn)的用量、周期取消率、平均获卵数、受精率、优质胚胎率、移植周期数、卵巢过度刺激综合征(OHSS)的发生率及妊娠结局.结果 周期移植率A组为92%(55/60),B组为63%(60/95),两组比较,差异有统计学意义(P<0.05).平均Gn用昔、平均获卵数、卵裂率、OHSS发生率A组分别为(1030±468)U、(10±6)个、82.2%(231/281)、0,B组分别为(1544±338)U、(14±4)个、94.0%(502/534)、35%(21/60),两组比较,筹异均有统计学意义(P<0.05);两组的受精率和优质胚胎率比较,差异无统计学意义(P>0.05).A组29例临床妊娠,每移植周期的临床妊娠率为53%(29/55),多胎妊娠发生率为14%(4/29);B组28例临床妊娠,每移植周期的临床妊娠率为47%(28/60),多胎妊娠发牛率为32%(9/28);两组比较,差异无统计学意义(P>0.05).结论 常规IVF周期巾改行IVM,不仅可以避免OHSS的发生和减少促排卵药物的使用,还可获得较高的临床妊娠率.     

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。     

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.     

Management of recurrent pregnancy loss associated with a parental carrier of a reciprocal translocation: a systematic review

This study reviews systematically the effectiveness of management strategies for carriers of a reciprocal translocation involving two chromosomes, ascertained on the basis of recurrent pregnancy loss. Subsequent pregnancy outcomes were tabulated based on whether management was medical or involved in vitro fertilization/preimplantation genetic diagnosis (IVF/PGD). A total of 129 cases from 13 articles met the criteria, of which 89% were managed medically. Before management, the overall live birthrate was 4% (19 of 484 pregnancies). Management was medical in 109 cases and IVF/PGD in 20 cases. Cumulative live birthrate was 74% (81 of 109 cases) in the medical management group and 35% (7 of 20) in the IVF/PGD group. Based on this systematic review, successful pregnancy outcomes are high following either medical management or IVF/PGD for carriers of a reciprocal translocation, ascertained on the basis of recurrent pregnancy loss. But it is difficult to compare outcomes directly for these two strategies because of the different end points reported. Understanding the differences is essential for effective counseling. Until a well-designed study comparing the two strategies is performed, or at least prospective cohort studies with strict entry criteria and definitions, the cumulative experience and success of both medical management and IVF/PGD must be used to counsel patients who are carriers of a reciprocal translocation, ascertained on the basis of recurrent pregnancy loss.     

Preconceptional diagnosis for Robertsonian translocation as an alternative to preimplantation genetic diagnosis in two situations: a pilot study

Introduction

Preimplantation genetic diagnosis (PGD) is widely used for women heterozygous for a Robertsonian translocation. Preconceptional diagnosis (PCD), performed before fertilization, may be an alternative to PGD, especially in countries where PGD is restricted or prohibited, as in France. It could also give different information and clarify the influence of reproductive and obstetric history.

Methods

In our study, translocation was diagnosed before ICSI in five cases (group A), and after newborn or fetal aneuploidy or miscarriage in two cases, (group B).

Results

First polar body (PB1) analysis using acrocentric centromeric probes was done for 85 PB1s, and aneuploidy rate was at 42.4%. Oocyte aneuploidy rate differed (p?<?0.0001) between groups A and B (30% vs 84%). Despite the small group sizes, we demonstrate a correlation (p?=?0.0358) of aneuploidy rate in polar bodies after 2 or more attempts. Three live births were recorded, all in group A.

Discussion

PCD could thus be an alternative to PGD. This pilot study also provides new prognostic information taking into account the women’s natural history, but further confirmation is required.     

Current features of preimplantation genetic diagnosis

More than 4000 preimplantation genetic diagnosis (PGD) cycles have been performed, suggesting that PGD may no longer be considered a research activity. The important present feature of PGD is its expansion to a variety of conditions, which have never been considered as an indication for prenatal diagnosis, including the late-onset disorders with genetic predisposition and preimplantation non-disease testing, with the further improvement of the accuracy of PGD for single gene disorders. PGD has also become a useful tool for the improvement of the effectiveness of IVF, through avoiding the transfer of chromosomally abnormal embryos, representing more than half of the embryos routinely transferred in IVF patients of advanced maternal age and other poor prognosis patients. PGD is of particular hope for the carriers of balanced chromosomal translocations, as it allows accurate pre-selection of a few balanced or normal embryos resulting from the extremely poor meiotic outcome, especially in reciprocal translocations. With the current progress in polymerase chain reaction- (PCR-) based detection of chromosomal abnormalities in oocytes and embryos, PGD may soon be performed for both chromosomal and single gene disorders using the same biopsied polar body or blastomere, frequently required with the currently expanded PGD application. The available clinical outcome data of more than 3000 PGD embryo transfers further suggest an acceptable pregnancy rate and safety of the procedure, as demonstrated by the follow-up information available for more than 500 children born from these PGD transfers.     

Outcome of preimplantation genetic diagnosis of translocations

Objective: To review 35 cases of preimplantation genetic diagnosis (PGD) of translocations with several methods, including telomeric probes.

Design: Retrospective study.

Setting: Clinical IVF laboratory.

Patient(s): Thirty-five couples with one partner carrying a chromosomal translocation.

Intervention(s): PGD of translocation after polar-body or embryo biopsy.

Main Outcome Measure(s): Pregnancy outcome.

Result(s): Several trends were observed. First, PGD can achieve a statistically significant reduction in spontaneous abortion, from 95% to 13%. Second, the chances of achieving pregnancy are correlated with 50% or more of the embryos being chromosomally normal. Third, patients with robertsonian translocations produced fewer abnormal gametes and more pregnancies than did patients with reciprocal translocations. Fourth, a new fluorescence in situ hybridization protocol for PGD of translocations, which involves applying telomeric probes, has proved adequately reliable with a 6% average error rate.

Conclusion(s): PGD of translocations achieves a statistically significant reduction in spontaneous abortion, both for polar-body and blastomere biopsy cases. Pregnancy outcome depended on the number of normal embryos available for transfer, with patients having <50% abnormal embryos achieving the most pregnancies. Because robertsonian translocations caused fewer abnormal embryos than reciprocal translocations, they also resulted in higher rates of implantation.     

Preimplantation genetic diagnosis significantly improves the pregnancy outcome of translocation carriers with a history of recurrent miscarriage and unsuccessful pregnancies

Preimplantation genetic diagnosis (PGD) for translocations has been shown to significantly reduce the risk of recurrent miscarriage, but because the majority of embryos produced are unbalanced, pregnancy rate is relatively low since 20% or more cycles have no normal or balanced embryos to transfer. The purpose of this study was to evaluate whether PGD could improve pregnancy outcome in translocation carriers with a history of two or more consecutive miscarriages and no live births. PGD for translocations was offered to translocation carriers with two or more previous miscarriages (average 3.5) and no live births (0/117 pregnancies) using a combination of distal and proximal probes to the breakpoints. After PGD, only 18.3% of embryos were normal or balanced. Only 5.3% of pregnancies were lost after PGD compared with 100% before PGD (P < 0.001). The cumulative pregnancy rate was 57.6% and the cumulative ongoing pregnancy rate was 54.5% in the short period of time of 1.24 IVF cycles, or 46.3% and 43.9% respectively per cycle. In conclusion, PGD significantly reduced losses and increased the number of viable pregnancies (P < 0.001). IVF plus PGD are a faster method of conceiving a live child than natural conception, at least for translocation carriers with recurrent miscarriages and no previous live births.