Correlation between oocyte morphology and the embryo aneuploidy rate in IVF cycles

Abstract

Purpose: To evaluate the aneuploidy rates of 13, 18, and 21 and the X and Y chromosomes in embryos from patients with morphologically normal oocytes and different oocyte dysmorphisms.

Methods: This prospective cohort study included 84 patients treated with in vitro fertilization (IVF) at a single academic center. The patients were divided into the following three groups: group 1 – women with cytoplasmic dysmorphisms (n?=?28), group 2 – women with extracytoplasmic dysmorphisms (n?=?28), and group 3 – women with morphologically normal oocytes (n?=?28). One blastomere from each embryo was analyzed for aneuploidies of chromosomes 13, 18, 21, X, and Y.

Results: The highest prevalence of aneuploid embryos was observed in the group 1 (68.4%) followed by the group 2 (38.9%) and the group 3 (31.3%) (р?<?0.0001). The adjusted OR for receiving an aneuploid embryo in the case of cytoplasmic dysmorphism was 3.6 (95% CI?=?1.8; 7.2), in the case of extracytoplasmic dysmorphisms – 1.3 (95% CI?=?0.7; 2.1).

Conclusions: Women with morphological oocyte abnormalities are at risk for developing aneuploid embryos during IVF cycles. We recommend that woman with cytoplasmic oocyte dysmorphisms receive additional genetic counseling to define the indications for the genetic screening of embryos.     

2433例孕妇血浆胎儿游离DNA无创性产前非整倍性检测结果分析

目的探讨应用高通量测序技术对孕妇血浆胎儿游离DNA进行无创性胎儿染色体非整倍性检测的准确性。方法选择2011年10月至2013年9月于佛山市妇幼保健院行无创性非整倍性产前基因检测的2433例名孕妇,孕周12-24w,均为单胎,年龄21-41岁。对无创性非整倍性筛查高风险的孕妇行羊膜腔穿刺或脐静脉血穿刺,行常规染色体核型分析。对筛查结果低风险者行电话随访其胎儿出生后情况,统计分析无创性产前非整倍性检测的准确性。结果2433例孕妇中,母体血浆胎儿游离DNA高通量测序技术检测出42例胎儿染色体非整倍性高风险。其中33例通过羊膜腔穿刺或脐静脉血穿刺对比分析,27例21三体高风险者行有创性产前诊断,26例为47,XN,＋21,l例为46,XN。2例18三体高风险者行进一步确诊,其中1例为47,XN,＋18,1例为46,XN。2例i3三体高风险孕妇结果均与穿刺结果为46,XN。1例XO高风险孕妇与穿刺结果为45X[25]／46,XX[25]。1例XXY高风险孕妇结果为47,XXY。孕妇血浆中游离胎儿DNA检测结果阴性者2391例,经电话随访有效者2145例,截止至2014年4月30日,已出生的新生儿均未发现唐氏综合征患儿。无创性非整倍体检测对常见染色体非整倍体的检出率100％,灵敏废100％,特异度99.8,假阳性率0.33％,假阴性率为0,阳性预测值87.9％。结论应用高通量测序技术在染色体非整倍性无创性检测具有很高的灵敏性,假阳性率很低,在胎儿染色体非整倍性疾病的产前检测中具有广泛的应用前景。     

Molecular cytogenetic and genetic aspects of globozoospermia: a review

Infertility is estimated to affect up to 15% of couples of reproductive age. Among the male factors, globozoospermia (also called round‐headed sperm syndrome) is a rare type of teratozoospermia accounting for <0.1% of male infertility. Lack of acrosome, whose production is a postmeiotic event in spermatogenesis, and round sperm head are its main characteristics. The acrosomeless spermatozoon is unable to go through the zona pellucida and fuse with the oolemma of the oocyte, and fertilisation failures have been attributed to a deficiency in oocyte activation capacity, even when intracytoplasmic sperm injection (ICSI) is attempted. The pathogenesis of this anomaly is still unclear but genetic factors are likely to be involved. DNA fragmentation rate has been reported for 16 globozoospermic males, usually using the terminal uridine nick‐end labelling (TUNEL) assay. Most of the patients had a DNA fragmentation index (DFI) higher than that in fertile men. The rate of aneuploidy for some specific chromosomes was increased in 12 among the 26 globozoospermic males reported in the literature. The same results (high DFI and aneuploidy rates) were observed in infertile males compared to fertile men, notably in those with oligoasthenozoospermia or teratozoospermia, independently of the origins. Mutations or deletions in three genes, SPATA16, PICK1 and DPY19L2, have been shown to be responsible for globozoospermia. Proteins coded by the first two genes localise to the Golgi apparatus and the proacrosomal granules that are transported in the acrosome. It is likely that other proteins involved in the acrosome formation remain to be identified.     

273例曾生育非整倍体患儿父母染色体核型分析

目的：探讨曾生育非整倍体患儿父母染色体核型异常的检出情况。方法：利用G显带技术对273例曾生育非整倍体患儿父母以及116例健康体检者进行染色体核型分析,必要时加做C显带。结果：273例样本中共检出72例染色体变异,其中包括4例染色体结构异常,检出率为1.46%;68例染色体多态变异,检出率为24.91%;剔除高龄女性样本后,多态变异检出率为64/255（25.10%）。116例对照组染色体核型共检出1例染色体结构异常,5例染色体多态变异,多态变异检出率为4.31%,2组多态变异检出率差异有统计学意义（P＜0.05）。结论：曾生育非整倍体患儿父母染色体多态变异具有较高检出率,应引起临床医生的重视。     

Correlation between embryo morphology and development and chromosomal complement

ObjectiveTo analyze the correlation between embryo morphology and the chromosomal status using the array comparative genomic hybridization [array comparative genomic hybridization (a-CGH)] technique for screening 23 chromosome pairs in a single blastomere biopsy from Day 3 embryos.MethodsOne thousand five hundred and fifty seven embryos were included from 203 cycle ICSI patients undergoing preimplantation genetic screening. The 23 chromosome pairs were analyzed by blastomere biopsy from day 3 embryos using a-CGH array method. Embryo development rate, fragmentation rate and chromosome status of the analyzed blastomeres were recorded and correlated with the aCGH results.ResultsThe incidence of chromosomal abnormalities was significantly higher in slow-and fast cleaving embryos at day 3 after insemination. The incidence of fragmentation and the type of fragmentation was associated with an increased incidence of chromosomal abnormalities. The symmetry of the blastomeres also correlated with the aneuploidy rates.ConclusionsEmbryo development rate and morphological parameter such as degree, type of fragmentation and the symmetry of the blastomeres to a large extent reflect the cytogenetic status of the embryo and thus are important in the selection of embryos with the highest implantation potential.     

胚胎植入前遗传学筛查的临床应用

随着辅助生殖技术和遗传学分析技术的发展,胚胎植入前遗传学筛查应用于胚胎染色体数目异常（非整倍体）检测,以期改善体外受精-胚胎移植的妊娠结局。新方法、新技术不断出现并应用于胚胎植入前遗传学筛查中,如囊胚期活检、比较基因组杂交技术、微阵列技术、第二代测序技术等,显著增加了诊断准确性,减少误诊风险。同时,胚胎植入前遗传学筛查的广泛应用也面临许多挑战。综述该领域的应用进展和面临的挑战。     

妊娠早期胎儿颈部透明层厚度与胎儿预后的前瞻性队列研究

目的探讨妊娠早期胎儿颈部透明层(NT)厚度与胎儿预后的关系。方法收集2015年12月至2018年12月于南京大学医学院附属鼓楼医院行妊娠早期胎儿NT厚度测量的单胎孕妇,共4958例建立前瞻性研究队列,进行妊娠早期胎儿结构超声筛查、妊娠早期血清学筛查、妊娠中期超声筛查及对新生儿出生后28 d的体格检查。根据妊娠早期超声筛查的结果,分为胎儿NT增厚(≥3.0 mm)者167例与NT厚度正常者4791例;将胎儿NT增厚的孕妇,分为胎儿单纯NT增厚者86例与NT增厚合并结构异常者81例。分析不同NT厚度胎儿的预后,并重点对单纯NT增厚与NT增厚合并结构异常胎儿的妊娠结局进行分析。妊娠早期超声筛查发现胎儿结构异常或血清学筛查结果为高风险的孕妇,经绒毛穿刺取样术行染色体微阵列分析(CMA)检测以明确产前诊断。结果(1)胎儿NT厚度正常孕妇的妊娠结局:共4791例孕妇,包括胎儿NT厚度正常且无结构异常者4726例,其中妊娠中期及产后新诊断结构异常83例,4688例活产;胎儿NT厚度正常但结构异常的孕妇65例,其中61例孕妇终止妊娠,4例活产。(2)胎儿单纯NT增厚孕妇的妊娠结局:86例孕妇中,66例(76.7%,66/86)行CMA检测,3例胎儿诊断为21三体综合征;除7例孕妇选择终止妊娠外,余79例行妊娠中期超声检查、新生儿出生后28 d体格检查、新生儿电话随访至6~21个月均未发现发育异常。(3)胎儿NT增厚合并结构异常孕妇的妊娠结局:81例孕妇中,73例(90.1%,73/81)行CMA检测,其中32例的胎儿为染色体非整倍体异常。70例选择终止妊娠,2例妊娠中期自然流产,9例活产。(4)NT增厚是否合并结构异常胎儿的产前诊断结果及预后比较:单纯NT增厚的胎儿染色体非整倍体的发生率为3.5%(3/86),合并结构异常者为39.5%(32/81),两者比较,差异有统计学意义(χ2=32.7,P<0.01);胎儿单纯NT增厚孕妇的健康新生儿存活率为91.9%(79/86),合并结构异常者为9.9%(8/81),两者比较,差异有统计学意义(χ2=112.3,P<0.01)。结论妊娠早期,超声筛查胎儿NT及结构,能提高出生缺陷的产前筛查率。单纯NT增厚胎儿的染色体非整倍体的发生率较低,新生儿健康存活率较高。     

荧光原位杂交技术在染色体非整倍体产前诊断中的应用研究

目的建立荧光原位杂交技术应用于未培养羊水标本的染色体非整倍体产前诊断。方法对于符合产前诊断指征的孕妇,于孕16-25周抽取羊水25ml,其中20ml用于传统的细胞培养和染色体G显带分析,其余5ml用荧光原位杂交方法诊断13、8、21、X、Y染色体非整倍体。结果100例受检样本中,染色体数目异常3例,其中21三体2例,45,X 1例。FISH方法与传统羊水细胞核型分析符合率100%。结论FISH技术具有快速、简便、特异的特点,可作为部分染色体非整倍体的快速产前诊断方法。     

何杰金氏淋巴瘤的非整倍体分析

应用流式细胞术和ＡｇＮｏＲｓ计数对何杰金氏淋巴瘤的非整倍体和核仁组成区资料分析。瘤细胞的ＤＮＡ指数为０．９５～１．４８，均值为１．２１±０．１２，非整倍体率为７５．０％（３０／４０），以超二倍体为主，％Ｓ和ＰＩ值分别为１８．３％和３０．６％。ＡｇＮｏＲｓ计数为２．５８～８．１４／核，均值为５．５４±０．５５。ＡｇＮｏＲｓ计数与％Ｓ有关，而与ＤＮＡ指数无关。上述分析可提供进一步对何杰金瘤细胞异质性的了解。