Preimplantation genetic testing as a preventive strategy for the transmission of mitochondrial DNA disorders.

Mitochondrial diseases are distinct types of metabolic and/or neurologic abnormalities that occur as a consequence of dysfunction in oxidative phosphorylation, affecting several systems in the body. There is no effective treatment modality for mitochondrial disorders so far, emphasizing the clinical significance of preventing the inheritance of these disorders. Various reproductive options are available to reduce the probability of inheriting mitochondrial disorders, including in vitro fertilization (IVF) using donated oocytes, preimplantation genetic testing (PGT), and prenatal diagnosis (PND), among which PGT not only makes it possible for families to have genetically-owned children but also PGT has the advantage that couples do not have to decide to terminate the pregnancy if a mutation is detected in the fetus. PGT for mitochondrial diseases originating from nuclear DNA includes analyzing the nuclear genome for the presence or absence of corresponding mutations. However, PGT for mitochondrial disorders arising from mutations in mitochondrial DNA (mtDNA) is more intricate, due to the specific characteristics of mtDNA such as multicopy nature, heteroplasmy phenomenon, and exclusive maternal inheritance. Therefore, the present review aims to discuss the utility and challenges of PGT as a preventive approach to inherited mitochondrial diseases caused by mtDNA mutations.

Beyond appearance: Can morphologically low-grade euploid blastocysts yield successful pregnancies?

Purpose: The primary objective of this investigation is to evaluate how morphological quality affects the pregnancy outcomes in euploid embryos determined by preimplantation genetic testing for aneuploidies (PGT-A). Concurrently, as a secondary objective, we aim to identify which specific aspects of morphological evaluation exert the most significant impact on these outcomes. Methods: A retrospective analysis of 451 single euploid embryo transfer cycles at our clinic was conducted. Embryos were evaluated based on the degree of blastocyst expansion, inner cell mass (ICM), trophectoderm (TE) morphology, and the day of blastocyst vitrification. Outcomes between morphologically low-grade and high-grade embryos were compared. Additionally, the study analyzed which morphological factors most influenced pregnancy outcomes. Results: Pregnancy outcomes were significantly lower in morphologically low-grade blastocysts compared to high-grade ones. Among the morphological evaluations, the ICM assessment was significantly associated with the live birth rate. Conclusion: Our study indicates that the morphological quality of euploid embryos, particularly the evaluation of the ICM, plays a crucial role in IVF-ET success.

Genomic aspects in reproductive medicine.

Infertility is a complex disease characterized by extreme genetic heterogeneity, compounded by various environmental factors. While there are exceptions, individual genetic and genomic variations related to infertility are typically rare, often family-specific, and may serve as susceptibility factors rather than direct causes of the disease. Consequently, identifying the cause of infertility and developing prevention and treatment strategies based on these factors remain challenging tasks, even in the modern genomic era. In this review, we first examine the genetic and genomic variations associated with infertility, and subsequently summarize the concepts and methods of preimplantation genetic testing in light of advances in genome analysis technology.

Live birth after single euploid frozen embryo transfer in a 39-year-old woman with high-grade mosaic Turner syndrome.

OBJECTIVE: To describe the reproductive and obstetric outcomes of an intracytoplasmic sperm injection cycle with preimplantation genetic testing for aneuploidy in an advanced reproductive-age woman with high-grade mosaic Turner syndrome. METHODS: Case report of a 39-year-old woman diagnosed with mosaic Turner Syndrome 45,X[90]/46,XX[10] karyotype who underwent in vitro fertilization treatment with blastocyst trophectoderm biopsy for preimplantation genetic testing using next-generation sequencing. RESULT(S): Two of the four blastocysts biopsied were euploid. The patient achieved ongoing pregnancy after the first single euploid frozen embryo transfer, followed by the birth of a healthy child. CONCLUSION: Autologous intracytoplasmic sperm injection cycles can be considered in a select group of advanced reproductive-age women diagnosed with high-grade mosaic Turner syndrome.

Preventable Hazards from in Vitro Fertilization - A Case Series of CF Patients from Bulgaria.

Pre-implantation genetic diagnosis (PGD) is not often performed when donor gametes are used, due to its high cost. This is with the presumption that the donors are healthy. We report on five cases of babies with confirmed cystic fibrosis (CF), being the result from in vitro fertilization (IVF) with donor (4 cases) or own gametes (one case). There has been no family history for CF in any of the families affected. The clinical presentation in the children ranged from meconium ileus to recurrent respiratory infections and severe nasal polyposis. The age of diagnosis also varied from birth until 9 years. Since one of the presented cases was discovered in a very renowned private IVF clinic, the clinic changed their own protocol, and currently they test every donor for CF carriership. The percentage of CF carriers in the donor population is roughly the same as the one predicted in the general population of Bulgaria - 1/33. Although PGD is costly, the costs for proper care for a CF patient are currently much higher. The more economical option would to screen every donor for CF carriership. IVF requires a lot of physical and psychological stamina. The couples that go through this procedure also require a great deal of hope. It is essential to be more preconscious for possible congenital diseases. We advocate every IVF center to test the donors for CF carriership or to provide PGD for their clients.

Birth of spinal muscular atrophy unaffected baby from genetically at-risk parents following a pre-implantation genetic screening: A case report.

Background: Spinal muscular atrophy (SMA) is characterized by the homozygous deletion of the survival motor neuron-1 gene. Pre-implantation genetic testing for monogenic diseases through in-vitrofertilization program was developed to provide a reliable genetic diagnostic method for SMA. Case presentation: The couple who was confirmed as carriers of SMA visited the Morula IVF Clinic, Jakarta, Indenesia seeking for an in-vitro fertilization expert opinion in relation to the pre-implantation genetic testing for SMA. Utilizing polymerase chain reaction-restriction fragment length polymorphism, we have successfully screened for unaffected embryos that were characterized by a normal presence of the survival motor neuron-1 exon 7-8 and survival motor neuron-2 exon 7-8. The frozen embryo was subsequently transferred and a healthy unaffected female baby was born with undetected deletion of the survival motor neuron-1 gene. Conclusion: This successful embryo pre-implantation screening case could potentially accommodate the demands of genetically at-risk couples who are apprehensive about conceiving a child who might inherit monogenic disorders such as SMA.

A prospective study to evaluate the gender prediction of blastocysts by using cell-free DNA within a culture medium.

Background: Preimplantation genetic diagnosis (PGD) has been used as an option for couples with the possibility of having a baby with a genetic disorder. The common method for performing this test involves isolating 1 cell from day 3 or a few cells from day 5 embryos and performing genetic studies on the cell-extracted DNA. This method is invasive and can cause abortion after implantation in the uterus. Because of this, 2 noninvasive methods for performing a PGD have been studied: PGD using blastocyst fluid and PGD using embryo culture medium. Objective: The aim of this study is to determine the sensitivity of the polymerase chain reaction (PCR) technique to detect the Y chromosome using cell-free DNA within a culture medium for gender prediction of blastocysts. Materials and Methods: In this study, the gender of 30 embryos on day 5 was determined using embryonic DNA extraction from the culture medium and the PCR technique to evaluate the sex-determining region Y and fragile X mental retardation genes. Then, the accuracy was assessed using ultrasound. Results: The results of the PCR technique showed that 7 embryos were male, but an ultrasound revealed that 13 were male. Conclusion: The given results indicated that, because of the low amount of DNA extracted from the culture medium, the diagnosis of the existence of the Y chromosome by this method is still not accurate enough for detecting the gender of the embryo.

National Canadian Survey on the Management of Noneuploid Embryos.

OBJECTIVE: To comprehensively describe current preimplantation genetic testing for aneuploidy (PGT-A) practices and management of non-euploid embryos in Canada. METHODS: This was a cross-sectional study utilizing an online survey distributed by email to all medical directors of fertility clinics with independent in vitro fertilization (IVF) embryology laboratories. The survey was designed to determine practice patterns regarding PGT-A usage; PGT-A reference laboratory, platform, and thresholds for classifying embryos; and management of embryos classified as mosaic, inconclusive, or aneuploid. RESULTS: Twenty-five medical directors (69%) participated in the survey. The majority of clinics (91%) offered PGT-A screening, with 45% of clinics offering PGT-A as routine screening. The majority of clinics (90%) that offered PGT-A received mosaicism data; 61% of these clinics had transferred mosaic embryos, and 94% would transfer mosaic embryos. Clinics that performed ≥1000 IVF cycles annually were more likely to have transferred mosaic embryos (100% vs. 45.5%; P = 0.043). The mean percentage of IVF cycles using PGT-A was lower in clinics that had transferred mosaic embryos (12.3% vs. 30.4%; P = 0.033). Only 1 clinic had transferred an aneuploid embryo, but 2 other clinics would consider this option. The majority of clinics (61%) that receive mosaicism data would recommend noninvasive prenatal testing (NIPT) following mosaic embryo transfer, with 22% of clinics indicating that this would be the only genetic test offered. CONCLUSION: We report significant practice variation in PGT-A and management of non-euploid embryos across Canada and highlight areas where consensus should be encouraged.

Factors affecting clinical manifestation of chromosomal imbalance in carriers of segmental autosomal mosaicism: differential impact of gender.

Mosaicism for unbalanced chromosomal rearrangements segmental mosaicism (SM) is rare, both in patients referred for cytogenetic testing and in prenatal diagnoses. In contrast, in preimplantation embryos SM is a frequent finding and, therefore, is even more challenging. However, there is no consistency among results of published studies on the clinical outcomes of embryos with SM, primarily due to the small number of reported cases. Moreover, there is the problem of predicting the potential for the optimal development of a mosaic embryo to a healthy individual. Therefore, we suggested comparing factors predisposing to favorable and poor prognoses, identified in postnatal and prenatal cohorts of SM carriers, with those obtained from studies on preimplantation embryos. We analyzed 580 published cases of SM including (i) postnatally diagnosed affected carriers, (ii) clinically asymptomatic carriers, (iii) prenatally diagnosed carriers, and (iv) miscarriages. We observed a concordance with preimplantation diagnoses regarding the clinical significance of the extent of mosaicism as well as a predominance of deletions over other types of rearrangements. However, there is no concordance regarding excessive involvement of chromosomes 1, 5, and 9 in unbalanced rearrangements and a preferential involvement of larger chromosomes compared to short ones. Paternal age was not found to be associated with SM in postnatally disease-defined individuals. We have identified maternal age and preferential involvement of chromosome 18 in rearrangements associated with clinical manifestations. Male predominance was found among normal pregnancy outcomes and among disease-defined carriers of rearrangements resulting in a gain of genomic material. Female predominance was found among abnormal pregnancy outcomes, among disease-defined carriers of loss and gain/loss rearrangements, and among transmitting carriers of gonadal SM, both affected and asymptomatic. According to data obtained from "post-embryo" studies, clinical manifestations of chromosomal imbalance are associated with a high proportion of abnormal cells, female gender, the type of rearrangement and involved chromosome(s), and maternal age. We believe these data are instructive in the challenging medical genetic counseling of parents faced with no option other than transfer of an embryo with segmental mosaicism.

Association of ovarian stimulation and embryonic aneuploidy in in vitro fertilization cycles with preimplantation genetic testing: A narrative systematic review.

The impact of gonadotropins used for COS on the rate of embryo aneuploidy in patients without the negative effects of age as a confounding factor, is still a subject of lively debate. We ran a systematic search for studies in MEDLINE, PubMed, Google Scholar and the Cochrane Library. A librarian coordinated the search in December of 2020. We included all original peer-reviewed papers in English, irrespective of study-design. There were no restrictions concerning method of amplification or platform used to analyze the amplified DNA. We used the PICO model to select the study population. We included women/couples submitted to COS for IVF with the intention to genetically analyze her/their embryos through PGT. The primary outcome was the rate of aneuploidy. We used the Newcastle-Ottawa scale (NOS) score to evaluate the quality of the studies included. The search yielded 73 citations, and 14 were eligible for analysis, which included data on 4805 cycles. Media quality NOS score was 8. Although it has been demonstrated that natural cycles are associated with aneuploidy, it does seem that more robust stimulations are indeed associated with a higher proportion of aneuploidy. Nevertheless, a higher response is associated with an increased number of euploid embryos available for transfer, which translates into more embryo-transfer cycles with a prospective higher cumulative live birth rate. Further evidence is needed to ascertain if there is a negative impact of COS, especially at the cellular level.

Preimplantation genetic testing and prenatal diagnosis in a family with type Ⅰ neurofibromatosis / 中华围产医学杂志

We report the implantation genetic testing and prenatal diagnosis of a family with neurofibromatosis type I (NF1). High-throughput sequencing combined with multiplex ligation-dependent probe amplification was performed to identify the pathogenic mutation sites, then verified by Sanger sequencing. The pathogenic mutation of c.4172G>C in the NF1 gene was found in the proband and his mother. After sequencing and single nucleotide polymorphism (SNP) haplotyping of the mutation sites in the embryos by establishing the SNP-linked haplotype, a well-developed blastocyst, without pathogenic mutations, was transplanted, and 28 d later, the ultrasound confirmed that the patient was pregnant. Amniotic fluid samples of the fetus were obtained at 19 +3 weeks for karyotyping and detection of the gene mutation site, which found the fetus did not carry the maternal c.4172G>C mutation of NF1 gene or any copy number variants of clear clinical significance. The patient delivered a healthy term girl by cesarean section, and no significant abnormalities were found during the follow-up to 10 months of age.

Utilization of preimplantation genetic testing in the USA.

PURPOSE: To evaluate the use of preimplantation genetic testing (PGT) and live birth rates (LBR) in the USA from 2014 to 2017 and to understand how PGT is being used at a clinic and state level. METHODS: This study accessed SART data for 2014 to 2017 to determine LBR and the CDC for years 2016 and 2017 to identify PGT usage. Primary cycles included only the first embryo transfer within 1 year of an oocyte retrieval; subsequent cycles included transfers occurring after the first transfer or beyond 1 year of oocyte retrieval. RESULTS: In the SART data, the number of primary PGT cycles showed a significant monotonic annual increase from 18,805 in 2014 to 54,442 in 2017 (P = 0.042) and subsequent PGT cycles in these years increased from 2946 to 14,361 (P = 0.01). There was a significant difference in primary PGT cycle use by age, where younger women had a greater percentage of PGT treatment cycles than older women. In both PGT and non-PGT cycles, the LBR per oocyte retrieval decreased significantly from 2014 to 2017 (P<0001) and younger women had a significantly higher LBR per oocyte retrieval compared to older women (P < 0.001). The CDC data revealed that in 2016, just 53 (11.4%) clinics used PGT for more than 50% of their cycles, which increased to 99 (21.4%) clinics in 2017 (P< 0.001). CONCLUSIONS: A growing number of US clinics are offering PGT to their patients. These findings support re-evaluation of the application for PGT.

The Prevention of Thalassemia Revisited: A Historical and Ethical Perspective by the Thalassemia International Federation.

Hemoglobinopathies are the most common monogenic disorders in humans; among them, thalassemia constitutes a serious medical and public health problem in high prevalence regions, in a geographical zone ranging from the Mediterranean Basin to China. In addition, migrations over the years have introduced thalassemia to many parts of the world. Although disease-specific programs are in place and accessible to most patients in prosperous countries, this is not the case in developing economies, where more than 75.0% of the patient population is born and lives; this concerns both prevention and treatment programs. In view of the significant improvements in public health and healthcare systems over the past few years, the Thalassemia International Federation has revisited the thalassemia prevention programs, initiatives and policies in some of its member countries, discussing their effectiveness and whether any changes in policy or public attitudes to thalassemia prevention have occurred through the recent years.

Should germline genome editing be allowed? The effect of treatment characteristics on public acceptability.

STUDY QUESTION: To what extent do characteristics of germline genome editing (GGE) determine whether the general public supports permitting the clinical use of GGE? SUMMARY ANSWER: The risk that GGE would cause congenital abnormalities had the largest effect on support for allowing GGE, followed by effectiveness of GGE, while costs, the type of application (disease or enhancement) and the effect on child well-being had moderate effects. WHAT IS KNOWN ALREADY: Scientific progress on GGE has increased the urgency of resolving whether and when clinical application of GGE may be ethically acceptable. Various expert bodies have suggested that the treatment characteristics will be key in determining whether GGE is acceptable. For example, GGE with substantial risks (e.g. 15% chance of a major congenital abnormality) may be acceptable to prevent a severe disease but not to enhance non-medical characteristics or traits of an otherwise healthy embryo (e.g. eye colour or perhaps in the future more complex traits, such as intelligence). While experts have called for public engagement, it is unclear whether and how much the public acceptability of GGE is affected by the treatment characteristics proposed by experts. STUDY DESIGN, SIZE, DURATION: The vignette-based survey was disseminated in 2018 among 1857 members of the Dutch general public. An online research panel was used to recruit a sample representing the adult Dutch general public. PARTICIPANTS/MATERIALS, SETTING, METHODS: A literature review identified the key treatment characteristics of GGE: the effect on the well-being of the future child, use for disease or enhancement, risks for the future child, effectiveness (here defined as the chance of a live birth, assuming that if the GGE was not successful, the embryo would not be transferred), cost and availability of alternative treatments/procedures to prevent the genetic disease or provide enhancement (i.e. preimplantation genetic testing (PGT)), respectively. For each treatment characteristic, 2-3 levels were defined to realistically represent GGE and its current alternatives, donor gametes and ICSI with PGT. Twelve vignettes were created by fractional factorial design. A multinominal logit model assessed how much each treatment characteristic affected participants' choices. MAIN RESULTS AND THE ROLE OF CHANCE: The 1136 respondents (response rate 61%) were representative of the Dutch adult population in several demographics. Respondents were between 18 and 89 years of age. When no alternative treatment/procedure is available, the risk that GGE would cause (other) congenital abnormalities had the largest effect on whether the Dutch public supported allowing GGE (coefficient = -3.07), followed by effectiveness (coefficient = 2.03). Costs (covered by national insurance, coefficient = -1.14), the type of application (disease or enhancement; coefficient = -1.07), and the effect on child well-being (coefficient = 0.97) had similar effects on whether GGE should be allowed. If an alternative treatment/procedure (e.g. PGT) was available, participants were not categorically opposed to GGE, however, they were strongly opposed to using GGE for enhancement (coefficient = -3.37). The general acceptability of GGE was higher than participants' willingness to personally use it (P < 0.001). When participants considered whether they would personally use GGE, the type of application (disease or enhancement) was more important, whereas effectiveness and costs (covered by national insurance) were less important than when they considered whether GGE should be allowed. Participants who were male, younger and had lower incomes were more likely to allow GGE when no alternative treatment/procedure is available. LIMITATIONS, REASONS FOR CAUTION: Some (e.g. ethnic, religious) minorities were not well represented. To limit complexity, not all characteristics of GGE could be included (e.g. out-of-pocket costs), therefore, the views gathered from the vignettes reflect only the choices presented to the respondents. The non-included characteristics could be connected to and alter the importance of the studied characteristics. This would affect how closely the reported coefficients reflect 'real-life' importance. WIDER IMPLICATIONS OF THE FINDINGS: This study is the first to quantify the substantial impact of GGE's effectiveness, costs (covered by national insurance), and effect on child well-being on whether the public considered GGE acceptable. In general, the participants were strikingly risk-averse, in that they weighed the risks of GGE more heavily than its benefits. Furthermore, although only a single study in one country, the results suggests that-if sufficiently safe and effective-the public may approve of using GGE (presumably combined with PGT) instead of solely PGT to prevent passing on a disease. The reported public views can serve as input for future consideration of the ethics and governance of GGE. STUDY FUNDING/COMPETING INTEREST(S): Young Academy of the Royal Dutch Academy of Sciences (UPS/RB/745), Alliance Grant of the Amsterdam Reproduction and Development Research Institute (2017-170116) and National Institutes of Health Intramural Research Programme. No competing interests. TRIAL REGISTRATION NUMBER: N/A.

Evaluation of extracellular vesicles and gDNA from culture medium as a possible indicator of developmental competence in human embryos.

Human embryos generated in vitro have a high incidence of chromosomal abnormalities that negatively affect pregnancy rate. Embryos generated in vitro secrete extracellular vesicles (EVs) into the culture medium that could be used potentially as indicators of embryo competence. This research aimed to evaluate the concentration and size of EVs and their gDNA content as an indicator of developmental competence in human embryos. Human embryos generated by intracytoplasmic sperm injection (ICSI) were classified morphologically as of either TOP, FAIR or POOR quality. Culture medium and developmentally arrested embryos (which were not able to be used for embryo transfer) were collected. Microvesicles, exosomes (MV/Exo) and apoptotic bodies (ABs) were isolated from culture medium. Nanoparticle tracking analysis (NTA) and array comparative genomic hybridization (aCGH) analysis were performed to evaluate EVs and their gDNA content. From NTA, the diameter (mean) of MVs/Exo from TOP quality embryos was higher (112.17 nm) compared with that of FAIR (108.02) and POOR quality embryos (102.78 nm) (P < 0.05). aCGH analysis indicated that MVs/Exo and ABs carried gDNA with the presence of 23 chromosome pairs. However, when arrested embryos were compared with their respective MVs/Exo and ABs, the latter had an increased rate of chromosomal abnormalities (24.9%) compared with embryos (8.7%) (P < 0.05). In conclusion, the size of EVs from culture medium might be an alternative for evaluating competence of human embryos, however more studies are needed to validate the use of gDNA from EVs as an indicator of embryo competence.

Técnicas de substituição de DNA mitocondrial para reduzir a transmissão da Síndrome de Leigh / Mitochondrial DNA replacement techniques to reduce Leigh syndrome transmission

A Síndrome de Leigh (SL) é uma doença neuro-metabólica congênita, que faz parte do grupo das encefalopatias fatais, com progressão e morte dentro de 2 anos, em média. A SL é causada por mutações no DNA que causam alterações na geração de ATP celular pelas mitocôndrias. As mitocôndrias contêm seu próprio DNA (mtDNA) e, ao contrário do DNA nuclear, o mtDNA é herdado somente da mãe. Mulheres portadores de mutações causadoras da SL podem vivenciar experiências muito tristes ao tentarem realizar o sonho da maternidade. As técnicas de substituição de mtDNA mutado com mtDNA saudável de doadora, oferecem a essas mulheres a possibilidade de terem uma criança geneticamente relacionada sem a SL. O desenvolvimento e a aplicação clínica de terapias de substituição de mtDNA já são uma realidade, tendo o primeiro bebê gerado a partir da técnica nascido em 2016. Mas será que essas técnicas são seguras? Neste trabalho, revisamos a SL e algumas técnicas de substituição de mtDNA já aplicadas em humanos, que envolvem a transferência de pronúcleos de zigotos ou de fuso acromático de oócitos. Concluímos que, apesar dos resultados promissores, ainda é cedo para assegurar a aplicabilidade clínica de técnicas de substituição de mtDNA em seres humanos. (AU)

Leigh syndrome (SL) is a congenital neurometabolic disease included in the group of fatal encephalopathies, with progression and death within 2 years on average. SL is caused by mutations in the DNA that cause changes in the generation of cellular ATP by mitochondria. Mitochondria contain their own DNA (mtDNA) and, unlike nuclear DNA, mtDNA is inherited only from the mother. Women with SL mutations may experience mournful situations when attempting to fulfill the dream of motherhood. Techniques for replacing mutant mtDNA with healthy donor mtDNA provide these women with the possibility of having a genetically related child without SL. The development and clinical application of mtDNA replacement therapies is a reality, and the first baby generated using the technique was born in 2016. However, are these techniques safe? In this article, we review SL and some mtDNA replacement techniques that have been used in humans, which involve zygote pronuclear transfer or oocyte spindle transfer. We conclude that, despite the promising results, it is too early to ensure that mtDNA replacement techniques are clinically applicable to humans. (AU)

Effectiveness of noninvasive embryo chromosome screening in preimplantation genetic testing at different ages / 中国医师杂志

Objective:To study the effectiveness of noninvasive embryo chromosome screening (NICS) based on blastocyst culture medium and cystic fluid in preimplantation genetic detection (PGT) of embryos in different age groups.Methods:A retrospective analysis of 62 couples who underwent PGT assisted pregnancy in Shenzhen Hospital of Peking University from January 2019 to June 2021. A total of 310 blastocysts were biopsied. At the same time, D3-6 blastocyst culture medium and blastocyst cavity fluid were collected for NICS. According to the age of the patients, they were divided into three groups: <35 years old group, 35≤age<40 years old group and ≥40 years old group. The results of NICS were compared with those of embryonic trophoblast (TE) biopsy in each group, and the consistency, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. Then the consistency, sensitivity, specificity, positive predictive value and negative predictive value of NICS and TE among the three age groups were statistically analyzed.Results:There was no statistically significant difference in the consistency rate of NICS and TE among the three age groups ( P>0.05), but there was an upward trend in the elderly group (35≤age<40 years and ≥40 years). There was no statistically significant difference in specificity, sensitivity and PPV among the three age groups ( P>0.05). There was significant difference in NPV between the ≥40 years group and the other two groups ( P<0.05). Conclusions:There was no statistical difference in the effectiveness of NICS among different age groups, However, there was an increasing trend in people ≥35 years of age.

Committee Opinion No. 406: Prenatal Testing After IVF With Preimplantation Genetic Testing for Aneuploidy.

OBJECTIVE: To review the approach to prenatal genetic screening and diagnosis for chromosomal abnormalities in pregnancies conceived through in vitro fertilization and following preimplantation genetic testing for aneuploidy. INTENDED USERS: General practitioners, family physicians, obstetricians, midwives, nurses, maternal-fetal medicine specialists, fertility specialists, genetic counsellors, geneticists, and other health care providers involved in prenatal screening. TARGET POPULATION: All individuals or couples who conceivd through in vitro fertilization and underwent preimplantation genetic testing for aneuploidy. EVIDENCE: Literature published in or before September 2018 was retrieved through searches of Medline, PubMed, and the Cochrane Library. SUMMARY STATEMENTS.

[Effect of exogenous gonadotropin dosage on embryo aneuploidy rate and pregnancy outcome in patients of preimplantation genetic test].

Objective: To investigate the effect of gonadotropin (Gn) on embryo aneuploidy rate and pregnancy outcome during preimplanptation genetic testing for aneuploidy (PGT-A) cycles. Methods: The clinical data of patients undergoing PGT-A cycle at the First Medical Center of the PLA General Hospital from January 1, 2013 to May 31, 2019 were retrospectively analyzed. Patients were divided into younger patient group (<35 years old) and elder patient group (≥35 years old) by maternal age, then divided into two groups in line with Gn dosage (≤2 250 U, >2 250 U), and into four groups by number of oocytes retrieved (1-5, 6-10, 11-15 and ≥16 oocytes). The embryo aneuploidy rate and pregnancy outcome between the groups were compared. Logistic regression was used to analyze the relationship between the cumulative amount of Gn, embryo aneuploidy rate and live-birth rate. Results: A total of 402 cycles (338 patients) and 1 883 embryos were included in the study. (1) In the younger patients, the aneuploidy rate was 52.5% (304/579) in the group of Gn≤2 250 U and 48.6% (188/387) in the group of Gn>2 250 U, with no significant difference between them (P=0.232). In the elderly patients, the difference in embryo aneuploidy rate between the two Gn group [57.9% (208/359) versus 60.6% (319/526)] was not statistically significant (P=0.420). (2) The embryonic aneuploidy rate in different protocol of ovary stimulation was analyzed,in the younger group, the embryonic aneuploidy rate in patients using antagonist long protocol was 50.3% (158/314), it was 50.0% (121/242) in agonist long protocol, 52.1% (207/397) in agonist short protocol and 6/13 in luteal phase protocol, no statistical difference was found in above groups (P=0.923); in the elder group, embryonic aneuploidy rate was 60.8% (191/314) in antagonist protocol, 58.4% (132/226) in agonist long protocol, 59.2%(199/336) in agonist short protocol, 5/9 in luteal phase protocol, respectively,no significant difference was found (P=0.938). (3) In the younger patients, the aneuploidy rate in 1-5 oocytes group, 6-10 oocytes group, 11-15 oocytes group and ≥16 oocytes group was 37.9% (11/29), 54.0% (94/174), 52.5% (104/198) and 50.1% (283/565) respectively, no significant difference was found between the groups (P=0.652); while in the elder patients, the difference between aneuploidy rate in each retrieved oocytes group [73.6% (89/121), 57.5% (119/207), 56.3% (108/192), 57.8% (211/365)] was statistically significant (P=0.046). (4) Logistic regression analysis of age, cumulative dosage of Gn, number of oocytes obtained, and embryo aneuploidy rate showed that there was no association between the amount of Gn and embryo aneuploidy rate (P>0.05); the increase in maternal age would increase the risk of aneuploidy rate of embryos, which was statistically significant (OR=1.031, 95%CI: 1.010-1.054, P=0.004); the increase in oocytes retrived would significantly decrease the risk of aneuploidy (OR=0.981, 95%CI: 0.971-0.991, P<0.01). (5) There was no significant difference in biochemical pregnancy rate [55.6% (80/144) versus 52.1% (63/121)], clinical pregnancy rate [50.0% (72/144) versus 47.9% (58/121)] and live-birth rate [46.5% (67/144) versus 40.5% (49/121)] between different Gn dosage groups (P=0.613, P=0.738, P=0.324). The logistic regression analysis showed that the maternal age, the cumulative dosage of Gn, the number of oocytes obtained, and the ovarian stimulation protocol had no effect on the live-birth rate (all P>0.05). Conclusions: In PGT-A cycle, the dosage of Gn has no association with the embryo aneuploidy rate and pregnancy outcome. In the patients ≥35 years old, the increase in number of oocytes obtained may decrease the risk of aneuploidy. Age is an important factor affecting the embryo aneuploidy in PGT-A cycle.

BIRTH OF HEALTHY NEONATE FOLLOWING PREIMPLANTATION GENETIC DIAGNOSIS IN A MOTHER WITH MOSAIC TURNER SYNDROME. CASE REPORT AND REVIEW OF THE LITERATURE.

OBJECTIVE: To report the case of a patient with mosaic Turner syndrome who underwent assisted reproduction treatment with preimplantation genetic testing for aneuploidy and gave birth to a healthy baby girl with normal karyotype; and to conduct a review of the literature on the usefulness of preimplantation genetic diagnosis in women with Turner syndrome. METHODS: A case of a 27 year-old woman diagnosed with mosaic Turner syndrome and secondary altered ovarian reserve, seen in a referral center for infertility management in Medellín, Colombia. The patient underwent in vitro fertilization followed by pre-implantation genetic testing to prevent transmission of Turner syndrome to her progeny. A literature search was conducted in the Medline via PubMed, Clinical Key, OVID, Embase, Lilacs, SciELO and Oxford Journals databases using the following terms: "Turner Syndrome," "Mosaic Turner," "Preimplantation Genetic Screening," "Preimplantation Genetic Testing," "Preimplantation Genetic Diagnosis," "Pregnancy," "Successful pregnancy." Inclusion criteria were case series and case reports, cohort studies and review articles published between January 1980 and June 2017 that included women with Turner syndrome achieving pregnancy by means of in vitro fertilization techniques with their own oocytes and who had undergone embryo biopsy for preimplantation genetic diagnosis. The search was limited to articles in Spanish and English. RESULTS: one study met the inclusion criteria. Both in this report and in our case, patients with mosaic Turner syndrome underwent several cycles of intracytoplasmic sperm injection (ICSI) with their own eggs, then performed embryonic biopsy for preimplantation genetic analysis using different techniques. In both cases, euploid embryos were transferred to the uterus with the subsequent birth of healthy girls with normal karyotype. CONCLUSIONS: Patients with mosaic Turner syndrome could benefit from preimplantation biopsy and genetic analysis to prevent transmission of the genetic defect to their progeny.

TITULO: RECIÉN NACIDO SANO DESPUÉS DE DIAGNÓSTICO GENÉTICO PREIMPLANTATORIO EN UNA MADRE CON SÍNDROME DE TURNER MOSAICO. REPORTE DE CASO Y REVISIÓN DE LA LITERATURA. OBJETIVO: reportar el caso de una paciente con síndrome de Turner en mosaico, a quien se le realizó un tratamiento de reproducción asistida con análisis genético preimplantatorio para aneuploidias, logrando el nacimiento de una niña sana con cariotipo normal, y realizar una revisión de la literatura sobre la utilidad del diagnóstico genético preimplantatorio en las mujeres con síndrome de Turner. METODOS: se presenta el caso de una mujer de 27 años, con diagnóstico de síndrome de Turner en mosaico y con alteración secundaria en la reserva ovárica, atendida en centro de referencia para el manejo de infertilidad en Medellín, Colombia, a quien se le realizó un tratamiento de fertilización in vitro con análisis genético preimplantatorio para prevenir la transmisión del síndrome de Turner a su descendencia. Se realizó una búsqueda de la literatura en las bases de datos Medline vía PubMed, Clinical Key, OVID, Embase, Lilacs, SciELO y Oxford Journals, con los siguientes términos: "Turner Syndrome", "Mosaic Turner", "Preimplantation Genetic Screening", "Preimplantation Genetic Testing", "Preimplantation Genetic Diagnosis", "Pregnancy", "Successful pregnancy". Como criterios de inclusión se consideraron artículos tipo series y reportes de casos, cohortes y artículos de revisión desde enero de 1980 hasta junio de 2017, que incluyeran mujeres con síndrome de Turner embarazadas por medio de técnicas de fertilización in vitro, con sus propios óvulos, y que hubiesen sido sometidas a biopsia embrionaria para diagnóstico genético preimplantatorio. La búsqueda se limitó a los idiomas español e inglés. RESULTADOS: un estudio cumplió con los criterios de inclusión. Tanto en este reporte como en nuestro caso, las pacientes con síndrome de Turner en mosaico se sometieron a varios ciclos de inyección intracitoplasmática de espermatozoides (ICSI) con sus propios óvulos, luego se realizó biopsia embrionaria para análisis genético preimplantatorio utilizando diferentes técnicas. En ambos casos se logró la transferencia al útero de embriones euploides con el posterior nacimiento de niñas sanas con cariotipo normal. CONCLUSIONES: Las pacientes con ST mosaico podrían beneficiarse de la biopsia embrionaria y análisis genético preimplantatorio para prevenir la transmisión del defecto genético a su descendencia. Palabras clave: síndrome de Turner; aneuploidía; diagnóstico preimplantación; análisis genético preimplantatorio; reserva ovárica.