Polar body based aneuploidy screening is poorly predictive of embryo ploidy and reproductive potential

Purpose

Polar body (polar body) biopsy represents one possible solution to performing comprehensive chromosome screening (CCS). This study adds to what is known about the predictive value of polar body based testing for the genetic status of the resulting embryo, but more importantly, provides the first evaluation of the predictive value for actual clinical outcomes after embryo transfer.

Methods

SNP array was performed on first polar body, second polar body, and either a blastomere or trophectoderm biopsy, or the entire arrested embryo. Concordance of the polar body-based prediction with the observed diagnoses in the embryos was assessed. In addition, the predictive value of the polar body -based diagnosis for the specific clinical outcome of transferred embryos was evaluated through the use of DNA fingerprinting to track individual embryos.

Results

There were 459 embryos analyzed from 96 patients with a mean maternal age of 35.3. The polar body-based predictive value for the embryo based diagnosis was 70.3 %. The blastocyst implantation predictive value of a euploid trophectoderm was higher than from euploid polar bodies (51 % versus 40 %). The cleavage stage embryo implantation predictive value of a euploid blastomere was also higher than from euploid polar bodies (31 % versus 22 %).

Conclusion

Polar body based aneuploidy screening results were less predictive of actual clinical outcomes than direct embryo assessment and may not be adequate to improve sustained implantation rates. In nearly one-third of cases the polar body based analysis failed to predict the ploidy of the embryo. This imprecision may hinder efforts for polar body based CCS to improve IVF clinical outcomes.     

The utility of embryo banking in order to increase the number of embryos available for preimplantation genetic screening in advanced maternal age patients

Purpose  

To determine if embryo banking with PGS is more optimal than proceeding with PGS regardless of embryo number.     

Biochemical screening for aneuploidy in patients with donor oocyte pregnancies compared with autologous pregnancies

Abstract

Objective: The objective was to determine if the rate of abnormal biochemical markers is different in pregnancies conceived by donor oocyte versus those conceived by autologous oocytes.

Methods: This is a retrospective cohort study of patients who underwent risk assessment for aneuploidy. Pregnancies conceived by egg donation were matched with control groups who conceived using their own eggs. The primary outcomes were incidence of low PAPP-A or free bHCG in the first trimester or elevated MSAFP, free bHCG or Inhibin A, or low uE3 in the second trimester.

Results: 260 singleton gestations were identified who conceived via oocyte donor. There was a significantly higher rate of unexplained elevated MSAFP in pregnancies conceived by egg donation (8% versus 2%, p?=?0.028) compared to a control group matched by maternal age. There was also a significantly higher rate of unexplained elevated MSAFP in pregnancies conceived by egg donation (7% versus 2%, p?=?0.01) compared to a control group matched by age of the egg donor.

Conclusion: Pregnancies conceived by egg donation are more likely to have an unexplained elevation in MSAFP compared to pregnancies not conceived by egg donation regardless of age. Egg donation itself is not associated with other biochemical abnormalities.     

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.     

A review of, and commentary on, the ongoing second clinical introduction of preimplantation genetic screening (PGS) to routine IVF practice

Purpose

Current re-introduction of “improved” preimplantation genetic screening (PGS#2) raises the question whether PGS#2 is ready for routine clinical application.

Methods

We assessed available evidence via review of published data for years 2005–2012, and review of currently ongoing registered clinical trials, based on searches under appropriate key words in PubMed, MEDLINE, Cochrane Database System Review and Google Scholar and http://www.ClinicalTrials.gov. In absence of prospective clinical trials, and due to limited available data, individual publications/ongoing studies are assessed.

Results

PGS#2 offers significant improvements in accuracy of aneuploidy diagnosis over PGS#1. By moving embryo biopsy from day-3 after fertilization (6–8 cell stage) to trophectoderm biopsy at blastocyst stage (day 5–6), PGS#2, however, adds additional co-variables to the analysis of efficacy of the procedure, which have special relevance for women with diminished ovarian reserve (DOR), who usually produce small egg and embryo numbers. Limited published data, claiming efficacy of PGS#2, as well as ongoing clinical trials, do not consider these additional co-variables, do not analyze outcomes by intent to treat and, therefore, have to be considered biased in patient selection.

Conclusions

Here reached conclusions are based on absence of adequate data rather than affirmative outcome assessments. They, therefore, are subject to change at any future date with generation of significant new data. Premature introduction of PGS#1 caused significant damage to patients. As currently no reliable PGS#2 data are available to suggest improvements in IVF outcomes, to avoid a repeat of the PGS#1 experience, PGS#2 should be considered experimental until data show otherwise.     

IVF/ICSI with or without preimplantation genetic screening for aneuploidy in couples without genetic disorders: a systematic review and meta-analysis

Purpose  To assess the efficacy of preimplantation genetic screening to increase ongoing pregnancy rates in couples without known genetic disorders. Methods  Systematic review and meta-analysis of randomized controlled trials. Two reviewers independently determined study eligibility and extracted data. Results  Ten randomized trials (1,512 women) were included. The quality of evidence was moderate. Meta-analyses using a random-effects model suggest that PGS has a lower rate of ongoing pregnancies (risk ratio=0.73, 95% confidence interval 0.62–0.87) and a lower rate of live births (risk ratio=0.76, 95% confidence interval 0.64–0.91) than standard in vitro fertilization/intracytoplasmic sperm injection. Conclusions  In women with poor prognosis or in general in vitro fertilization program, in vitro fertilization/intracytoplasmic sperm injection with preimplantation genetic screening for aneuploidy does not increase but instead was associated with lower rates of ongoing pregnancies and live births. The use of preimplantation genetic screening in daily practice does not appear to be justified. Capsule   Preimplantation genetic screening does not increase pregnancy rates in advanced maternal age, recurrent implantation failure, repeated miscarriages, or in general IVF population.     

Follicular fluid protein content (FSH, LH, PG4, E2 and AMH) and polar body aneuploidy

Purpose

Our objective was to identify a marker for oocyte aneuploidy in follicular fluid (FF) in women with an increased risk of oocyte aneuploidy after controlled ovarian hyperstimulation.

Materials and methods

Three groups of oocytes were constituted for polar body screening by FISH (chromosomes 13, 16, 18, 21 and 22): Group 1, advanced maternal age (n = 156); Group 2, implantation failure (i.e. no pregnancy after the transfer of more than 10 embryos; n = 101) and Group 3, implantation failure and advanced maternal age (n = 56). FSH and other proteins were assayed in the corresponding FF samples.

Results

Of the 313 oocytes assessed, 35.78 % were abnormal. We found a significant difference between the follicular FSH levels in normal oocytes and abnormal oocytes (4.85 ± 1.75 IU/L vs. 5.41 ± 2.47 IU/L, respectively; p = 0.021). We found that the greater the number of chromosomal abnormalities per oocyte (between 0 and 3), the higher the follicular FSH level.

Conclusion

High FF FSH levels were associated with oocyte aneuploidy in women having undergone controlled ovarian hyperstimulation.     

Lipocalin-1: a potential marker for noninvasive aneuploidy screening

This study has identified the first protein, lipocalin-1, in the secretome of human blastocysts that is associated with chromosome aneuploidy. The development of a noninvasive technique to determine an embryo's developmental competence, including chromosomal constitution, by analysis of spent IVF culture medium will be a powerful tool for embryo selection in assisted reproductive technologies.     

The association between the oocyte pool and aneuploidy: a comparative study of the reproductive potential of young and aged mice

Purpose

The present study examined the effect of aging on female reproductive potential.

Methods

Six-week-old and 9-month-old CD1 mice were referred to as the ‘young’ and ‘aged’ groups, respetively. Oocytes were collected after superovulation, and their viability were compared using parthenogenetic activation. The aneuploidy of the oocytes (MII) was assessed using chromosome spread, and the whole ovarian follicle number was counted using an unbiased stereological method. Serum hormone levels were measured using the radio-immunity method, and the expression of the Cohesin subunit genes in the oocytes (GV) were assessed using RT-PCR.

Results

The mean number of recovered (25.8 vs. 16.2; P < 0.05) and live oocytes (24.0 vs. 11.73; P <0.01) per head in the young-mice group (6-week-old) was significantly higher than that of the aged group (9-month-old). The aneuploidy rate of the ovulated oocytes in the aged group was significantly higher than that of the young group (36.8 % vs. 10 %; P < 0.01), and the rate of blastocyst formation in the young group (85.23 %) was significantly higher than that of the aged group (81.2 %; P <0.05). The number of primordial follicles (the oocyte pool) per ovary in the aged group was significantly decreased compared with the young group (330 ± 33.51 vs. 2079.6 ± 420.70; P < 0.01), and the level of AMH in the aged group was significantly higher than that of the young group (4.66 ± 0.11 ng/ml vs. 4.07 ± 0.18 ng/ml; P < 0.01).

Conclusions

We propose that maternal aging significantly reduces the oocyte pool, superovulation efficiency and developmental potential and increases the oocyte aneuploidy rate.

Electronic supplementary material

The online version of this article (doi:10.1007/s10815-013-0160-5) contains supplementary material, which is available to authorized users.     

Sperm meiotic segregation, aneuploidy and high risk of delivering an affected offspring in carriers of non-Robertsonian translocation t(13;15)

Purpose

To determine the percentage of unbalanced spermatozoa and an interchromosomal effect in two carriers of balanced translocations t(13;15)(q32;q26) and t(13;15)(q32;p11.2).

Methods

Sperm nuclei analysis by fluorescent in situ hybridization for detection of percentage of unbalanced spermatozoa and sperm with disomy of chromosomes X, Y, 8, 18, 21 and diploidy.

Results

The incidence of unbalanced spermatozoa was 50.5 % and 44.6 % in patient 1 (P1) and patient 2 (P2), respectively. Partial disomy of chromosome 13 was detected in 13.4 % and 21.3 % of sperm in P1 and P2, respectively. The unbalanced karyotype der(15)t(13;15) was found previously in a son of P1 and in two adult relatives, and prenatally in the family of P2. This demonstrates a high risk of delivering an affected offspring. Significantly increased frequencies of chromosomes 8, 18, X and XY disomy and diploidy were observed in P2, which might either indicate an interchromosomal effect or be related to his asthenoteratozoospermia.

Conclusions

Since the proportions of unbalanced spermatozoa and the risk of delivering an affected offspring are high, prenatal or preimplantation genetic diagnosis is recommended for such patients.     

Detection of aneuploidy rate for chromosomes X,Y and 8 by fluorescence in-situ hybridization in spermatozoa from patients with severe non-obstructive oligozoospermia

Purpose  

To evaluate the frequency of sperm nuclei disomy for chromosomes 8, X, and Y in patients with severe non-obstructive oligozoospermia and to assess possible correlations between sperm nuclei aneuploidy and semen parameters or a particular clinical phenotype.     

Clinical,social and ethical issues associated with non-invasive prenatal testing for aneuploidy

Non-invasive prenatal testing (NIPT), based on analysis of cell-free foetal DNA, is rapidly becoming a preferred method to screen for chromosomal aneuploidy with the technology now available in over 90 countries. This review provides an up-to-date discussion of the key clinical, social and ethical implications associated with this revolutionary technology. Stakeholders are positive about a test that is highly accurate, safe, can be perfomed early in pregnancy, identifies affected pregnancies that might otherwise have been missed and reduces the need for invasive testing. Nevertheless, professional societies currently recommend it as an advanced screening test due to the low false positive rate (FPR). Despite the practical and psychological benefits, a number of concerns have been raised which warrant attention. These include the potential for routinisation of testing and subsequent impact on informed decision-making, an “easy” blood test inadvertently contributing to women feeling pressured to take the test, fears NIPT will lead to less tolerance and support for those living with Down syndrome and the heightened expectation of having “perfect babies”. These issues can be addressed to some extent through clinician education, patient information and establishing national and international consensus in the development of comprehensive and regularly updated guidelines. As the number of conditions we are able to test for non-invasively expands it will be increasingly important to ensure pre-test counselling can be delivered effectively supported by knowledgeable healthcare professionals.     

SpermCheck: a simplified screening assay for immunological infertility

SpermCheck (Bio-Rad Laboratories, Hercules, CA), a new screening test for regional surface antibodies on motile sperm, uses monodispersed latex microspheres of uniform size as a vehicle to link rabbit antihuman immunoglobulins (IgA, IgG, IgM) and provides both negative and positive control sera, as well as sufficient buffer for sperm preparation in ambient CO2 atmosphere. When compared with reference data available for the immunobead test (IBT), the direct protocol (semen) for SpermCheck yielded 94.4% sensitivity with 100% specificity; the indirect protocol (serum) provided a sensitivity of 100% with 94.7% specificity. The microspheres of SpermCheck maintain a nearly uniform concentration per volume, with none to negligible clumping. The greater difference between the optical densities of latex and cytoplasm allows use of a light microscope for the rapid assessment of the percent of regional binding rather than the phase-contrast microscope required for the IBT. SpermCheck eliminates many difficulties encountered with the IBT, making SpermCheck a convenient screening assay for use in the physician's office.     

反复种植失败人群年龄、BMI与非整倍体的关系分析

目的 探讨年龄、身体质量指数(body mass index,BMI)对反复种植失败人群的非整倍体的影响.方法 共纳入2017年5月至2020年6月因反复种植失败行植入前非整倍性基因测试(preimplantation genetic testing for aneuploidy,PGT-A)治疗的79个周期,按取卵年...     

PGD and aneuploidy screening for 24 chromosomes: advantages and disadvantages of competing platforms

Diagnosis of embryos for chromosome abnormalities, i.e. aneuploidy screening, has been invigorated by the introduction of microarray-based testing methods allowing analysis of 24 chromosomes in one test. Recent data have been suggestive of increased implantation and pregnancy rates following microarray testing. Preimplantation genetic diagnosis for infertility aims to test for gross chromosome changes with the hope that identification and transfer of normal embryos will improve IVF outcomes. Testing by some methods, specifically single-nucleotide polymorphism (SNP) microarrays, allow for more information and potential insight into parental origin of aneuploidy and uniparental disomy. The usefulness and validity of reporting this information is flawed. Numerous papers have shown that the majority of meiotic errors occur in the egg, while mitotic errors in the embryo affect parental chromosomes at random. Potential mistakes made in assigning an error as meiotic or mitotic may lead to erroneous reporting of results with medical consequences. This study's data suggest that the bioinformatic cleaning used to 'fix' the miscalls that plague single-cell whole-genome amplification provides little improvement in the quality of useful data. Based on the information available, SNP-based aneuploidy screening suffers from a number of serious issues that must be resolved.