To transfer or not to transfer: the dilemma of mosaic embryos - a narrative review.

A frequent finding after preimplantation genetic diagnostic testing for aneuploidies using next-generation sequencing is an embryo that is putatively mosaic. The prevalence of this outcome remains unclear and varies with technical and external factors. Mosaic embryos can be classified by the percentage of cells affected, type of chromosome involvement (whole or segmental), number of affected chromosomes or affected cell type (inner mass cell, trophectoderm or both). The origin of mosaicism seems to be intrinsic as a post-zygotic mitotic error, but some external factors can play a role. As experience has increased with the transfer of mosaic embryos, clinical practice has gradually become more flexible in recent years. Nevertheless, clinical results show lower implantation, pregnancy and clinical pregnancy rates and higher miscarriage rates with mosaic embryo transfer when compared with the transfer of euploid embryos. Prenatal diagnosis is highly recommended after the transfer of mosaic embryos. This narrative review is intended to serve as reference material for practitioners in reproductive medicine who must manage a mosaic embryo result after preimplantation genetic testing for aneuploidies.

The importance of standardizing criteria for PGT-A interpretation of blastocysts analyzed by next-generation sequencing.

OBJECTIVE: To compare the preimplantation genetic testing for aneuploidy (PGT-A) results using the three most frequent criteria employed by preimplantation genetic laboratories and evaluate its impact on the number of euploid embryos available for transfer. METHODS: Retrospective and descriptive study including patients who underwent PGT-A between January 2018 and December 2020. Five hundred and nine PGT-A cycles and 2,079 blastocysts were analyzed by next-generation sequencing (NGS). We re-assigned the diagnosis of all blastocysts using three different criteria: strict (mosaicism thresholds from 20% to 80%), standard (from 30% to 70%) and excluding (mosaicism is not reported). We compared the euploid, aneuploid and mosaic embryos obtained in each criteria used. RESULTS: We observed PGT-A results discrepancies in 32.5% (165/509) of the cycles when the three different criteria were applied. The standard and excluding criteria showed 92 more euploid embryos (875/2,079) compared to the strict criteria (783/2,079). Evaluating the PGT-A results per cycle with the strict, standard and excluding criteria, the euploidy rates were 34.0%, 38.4% and 38.4% (p<0.001); aneuploidy rates were 59.0%, 55.8% and 61.6% (p<0.001) and mosaic rates were 7.0% and 5.8% (p<0.047), respectively. The mean number of euploid blastocysts available for transfer was 1.54±1.67 with the strict criteria, while the possibility to obtain an euploid embryo was higher if the standard or the excluding criteria were used 1.72±1.78 (p<0.001). CONCLUSIONS: This study highlights the importance of standardizing the criteria used for the interpretation of PGT-A blastocysts. We observed significant differences on PGT-A results associated solely to the criteria used.

ART in Latin America: the Latin American Registry, 2020.

RESEARCH QUESTION: What was the utilization, effectiveness and safety of assisted reproductive technology (ART) in Latin America during 2020? DESIGN: Retrospective collection of multinational data on ART performed by 188 institutions in 16 countries. RESULTS: Overall, 87,732 initiated cycles resulted in 12,778 deliveries and 14,582 births. The major contributors were Brazil (46.0%), Mexico (17.0%) and Argentina (16.8%). However, the highest utilization (cycles/million inhabitants) was Uruguay with 558, followed by Argentina with 490 and Panama with 425 cycles/million. Globally, women aged ≥40 years increased to 34% while women ≤34 dropped to 24.7%. After removing freeze-all cycles, the delivery rate per oocyte retrieval was 14.8% for intracytoplasmic sperm injection and 15.6% for IVF. Single-embryo transfer (SET) represented 38.3% of all fresh transfers, with delivery rate per transfer of 20.0%; this increased to 32.4% for elective SET (eSET) and 34.2% for blastocyst eSET, compared with blastocyst elective double embryo transfer (eDET) of 37.9%. However, multiple births increased from 1% in eSET to 30.5% in eDET. Perinatal mortality increased from 7.7‰ in singletons to 24.4‰ in twins and 64.0‰ in triplets. Frozen embryo transfer (FET) represented 66.6% of all transfers, with a delivery rate/transfer of 29.0%, significantly higher than 23.9% after fresh transfers at all ages (p<0.0001). Preimplantation genetic testing, reported in 8920 cycles, significantly improved delivery rate and decreased miscarriage rates at all ages (p≤0.041), including oocyte donation (p=0.002). Endometriosis was diagnosed in 28.3% of cases. The delivery rate in 5779 women after removal of peritoneal endometriosis was significantly better than tubal and endocrine factors in women aged 35-39 (p=0.0004) and women aged ≥40 (p=0.0353). CONCLUSIONS: Systematic collection and analysis of big data in a south-south cooperation model allow regional growth by implementing evidence-based reproductive decisions.

Impact of inactivated SARS-CoV-2 vaccination on embryo ploidy: a retrospective cohort study of 133 PGT-A cycles in China.

BACKGROUND: Unsubstantiated concerns have been raised on the potential correlation between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and infertility, leading to vaccine hesitancy in reproductive-aged population. Herein, we aim to evaluate the impact of inactivated SARS-CoV-2 vaccination on embryo ploidy, which is a critical indicator for embryo quality and pregnancy chance. METHODS: This was a retrospective cohort study of 133 patients who underwent preimplantation genetic testing for aneuploidy (PGT-A) cycles with next-generation sequencing technology from June 1st 2021 to March 17th 2022 at a tertiary-care medical center in China. Women fully vaccinated with two doses of Sinopharm or Sinovac inactivated vaccines (n = 66) were compared with unvaccinated women (n = 67). The primary outcome was the euploidy rate per cycle. Multivariate linear and logistic regression analyses were performed to adjust for potential confounders. RESULTS: The euploidy rate was similar between vaccinated and unvaccinated groups (23.2 ± 24.6% vs. 22.6 ± 25.9%, P = 0.768), with an adjusted ß of 0.01 (95% confidence interval [CI]: -0.08-0.10). After frozen-thawed single euploid blastocyst transfer, the two groups were also comparable in clinical pregnancy rate (75.0% vs. 60.0%, P = 0.289), with an adjusted odds ratio of 6.21 (95% CI: 0.76-50.88). No significant associations were observed between vaccination and cycle characteristics or other laboratory and pregnancy outcomes. CONCLUSIONS: Inactivated SARS-CoV-2 vaccination had no detrimental impact on embryo ploidy during in vitro fertilization treatment. Our finding provides further reassurance for vaccinated women who are planning to conceive. Future prospective cohort studies with larger datasets and longer follow-up are needed to confirm the conclusion.

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.

Results of Preimplantation Genetic Testing for Aneuploidy (PGT-A) in a Cohort of 319 Embryos: Experience in a Fertility Clinic in Colombia.

OBJECTIVE: To analyze the results of the preimplantation genetic testing for aneuploidy at the Instituto de Fertilidad Humana - Inser Bogotá, Colombia, from 2016 to 2020. METHODS: This study is an observational, retrospective, and correlative analysis of biopsies from 319 embryos (from 54 patients) submitted to preimplantation genetic testing for aneuploidy by different molecular techniques. RESULTS: Of the 54 patients included in the study, 42 provided their own oocytes, and 12 used donated oocytes. The main indication to perform the preimplantation genetic testing was advanced maternal age. We obtained 319 embryos: Ninety-one (28.5%) euploid, 197 (61.8%) aneuploid and 31 (9.7%) with no detectable DNA. The highest rate of aneuploid embryos was found in patients over 40 years (72.7%), and the euploidy rate in patients under 35 years was 37.1%. After the transfer of euploid embryos, the rates for implantation, ongoing pregnancy, live birth, and miscarriage were 40%, 50%, 40.6%, and 0%, respectively. Older maternal age correlated with higher numbers of aneuploid embryos and lower numbers of both euploid and 5-day embryos. CONCLUSIONS: There was a positive correlation between maternal age and aneuploidy rate. Complex chromosomal abnormalities were the most frequent aneuploidies, followed by mosaicism and double aneuploidies. The miscarriage rate after the transfer of euploid embryos was 0 %.

Pronuclear and blastocyst morphology are associated age-dependently with embryo ploidy in in vitro fertilization cycles.

This retrospective study aimed to assess the relationship between standard markers of embryo morphology, maternal age and blastocyst ploidy determined by trophectoderm (TE) biopsy and Next-generation Sequencing (NGS). A total of 774 oocytes and embryos from 288 PGT-A cycles were scored for pronuclear, cleavage stage and blastocyst morphology. Pronuclear oocytes aligned between the nuclei and presenting equal number of nucleolus precursor bodies (NPBs) were designated Z1, oocytes showing equal number of NPBs, but not aligned, as Z2 while Z3 oocytes had an unequal number of NBPs between the nuclei or NPBs aligned in one nucleus and non-aligned in the other. Pronuclear oocytes with unequal-sized or non-aligned nuclei were designated Z4. Blastocysts were graded as BL1 (AA, AB or BA), BL2 (BB or CB) and BL3 (BC or CC) based on the combination of inner cell mass (ICM) and TE scores. Pronuclear and blastocyst morphology were correlated with aneuploidy in a < 40-year-old group (p < 0.01 and p < 0.05, respectively), but not in those ≥40 years. Interestingly, BL3 blastocysts classified as Z1 or Z3-Z4 on day-1 had different aneuploidy rates (BL3/Z1 = 46.7% vs. BL3/Z3-Z4 = 90.0%, p < 0.05). In summary, our data showed that pronuclear and blastocyst morphology are associated with blastocyst ploidy in younger patients. This may help embryo selection for embryo transfer and decision-making on which blastocysts should be biopsied in PGT-A cycles.

Impact of inactivated SARS-CoV-2 vaccination on embryo ploidy: a retrospective cohort study of 133 PGT-A cycles in China

BACKGROUND: Unsubstantiated concerns have been raised on the potential correlation between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and infertility, leading to vaccine hesitancy in reproductive-aged population. Herein, we aim to evaluate the impact of inactivated SARS-CoV-2 vaccination on embryo ploidy, which is a critical indicator for embryo quality and pregnancy chance. METHODS: This was a retrospective cohort study of 133 patients who underwent preimplantation genetic testing for aneuploidy (PGT-A) cycles with next-generation sequencing technology from June 1st 2021 to March 17th 2022 at a tertiary-care medical center in China. Women fully vaccinated with two doses of Sinopharm or Sinovac inactivated vaccines (n = 66) were compared with unvaccinated women (n = 67). The primary outcome was the euploidy rate per cycle. Multivariate linear and logistic regression analyses were performed to adjust for potential confounders. RESULTS: The euploidy rate was similar between vaccinated and unvaccinated groups (23.2 ± 24.6% vs. 22.6 ± 25.9%, P = 0.768), with an adjusted ß of 0.01 (95% confidence interval [CI]: -0.08-0.10). After frozen-thawed single euploid blastocyst transfer, the two groups were also comparable in clinical pregnancy rate (75.0% vs. 60.0%, P = 0.289), with an adjusted odds ratio of 6.21 (95% CI: 0.76-50.88). No significant associations were observed between vaccination and cycle characteristics or other laboratory and pregnancy outcomes. CONCLUSIONS: Inactivated SARS-CoV-2 vaccination had no detrimental impact on embryo ploidy during in vitro fertilization treatment. Our finding provides further reassurance for vaccinated women who are planning to conceive. Future prospective cohort studies with larger datasets and longer follow-up are needed to confirm the conclusion.

Whole-genome amplification/preimplantation genetic testing for propionic acidemia of successful pregnancy in an obligate carrier Mexican couple: A case report.

BACKGROUND: Identifying a potential single monogenetic disorder in healthy couples is costly due to the Assisted Reproduction facilities' current methodology for screening, which focuses on the detecting multiple genetic disorders at once. Here, we report the successful application of a low-cost and fast preimplantation genetic testing for monogenic/single gene defects (PGT-M) approach for detecting propionic acidemia (PA) in embryos obtained from a confirmed heterozygous propionyl-CoA carboxylase alpha subunit (PCCA) couple. CASE SUMMARY: A fertile 32-years old Mexican couple with denied consanguinity sought antenatal genetic counseling. They were suspected obligate PA carriers due to a previous deceased PA male newborn with an unknown PCCA/propionyl-CoA carboxylase beta subunit (PCCB) genotype. Next-Generation Sequencing revealed a heterozygous genotype for a pathogenic PCCA variant (c.2041-1G>T, ClinVar:RCV000802701.1; dbSNP:rs1367867218) in both parents. The couple requested in vitro fertilization (IVF) and PGT-M for PA. From IVF, 12 oocytes were collected and fertilized, of which two resulted in high-quality embryos. Trophectoderm biopsies and Whole Genome Amplification by a fragmentation/amplification-based method were performed and revealed that the two embryos were euploid. End-point polymerase chain reaction and further Sanger sequencing of the exon-intron borders revealed a wild-type PCCA male embryo and a heterozygous c.2041-1G>T female embryo. Both embryos were transferred, resulting in a clinical pregnancy and the delivery of a healthy male newborn (38 wk, weight: 4080 g, length: 49 cm, APGAR 9/9). The absence of PA was confirmed by expanded newborn screening. CONCLUSION: We show that using PGT-M with Whole Genome Amplification templates, coupled with IVF, can reduce the transmission of a pathogenic variant of the PCCA gene.

Preimplantation genetic testing for aneuploidies does not increase success rates in fresh oocyte donation cycles: a paired cohort study.

PURPOSE: To determine whether in vitro fertilization cycles using fresh oocyte donations benefit from preimplantation genetic testing for aneuploidies. METHODS: A paired cohort study compared 44 fresh oocyte donation cycles with or without preimplantation genetic testing for aneuploidy (PGT-A). The sibling oocyte study analyzed fertilized oocytes, blastocyst development, and euploidy rate. Only frozen embryo transfers were performed. Pregnancy, implantation, biochemical pregnancy, miscarriage, stillbirth, live birth, and twin pregnancy rates were analyzed between groups. RESULTS: Fresh oocyte donation cycles between PGT-A and non-PGT-A groups were similar in all laboratory and clinical outcomes. A euploidy rate of 74.2% was observed in the PGT-A group. Although a slight trend was observed for implantation rate in the PGT-A group, it was not statistically significant. No difference was observed for live birth between groups. CONCLUSION: PGT-A associated with fresh oocyte donation cycles does not improve clinical outcomes and can be seen as over-treatment for patients.

Rate of Post-Fertilization Mitotic Activity Predicts Embryonic Competence via Next Generation Sequencing: An Analysis of 39,301 Cleavage Stage Embryos.

OBJECTIVE: To investigate the association between cleavage stage development, embryonic competence, and euploidy in patients undergoing in vitro fertilization (IVF) with subsequent next generation sequencing. METHODS: The retrospective cohort study included patients at an academic fertility center who underwent IVF with at least one cleavage stage embryo from 2016 to 2019. Embryos were analyzed as slow (<6 cells), intermediate (6-8 cells), or fast (>8 cells); day 3 cell count was also analyzed as a continuous variable. Primary outcomes were blastulation rate, biopsied blastocyst rate, and euploid rate. Odds of blastulation, biopsy, and euploidy were also calculated. Additionally, we modeled the predicted probability of an embryo reaching blastulation, biopsy, and euploidy based on cleavage stage development. RESULTS: When compared with intermediate and slow cohorts, fast cleaving embryos had significantly higher rates of blastulation (82.70% vs. 75.13 vs. 42.48%), biopsy (55.04% vs. 44.00% vs. 14.98%), and euploidy (50.65% vs. 47.93% vs. 48.05%). After adjustment for covariates, there was a significant association between cleavage stage development and odds of blastulation (OR 1.38, 95% CI 1.29-1.48), biopsy (OR 1.42, 95% CI 1.34-1.51), and euploidy (OR 1.08, 95% CI 1.01-1.17). Finally, we observed significant associations between cleavage stage development and predicted probability of reaching blastulation (OR 1.29, 95% CI 1.27-1.32), biopsy (OR 1.24, 95% CI 1.22-1.26), and euploidy (OR 1.02, 95% CI 1.01-1.04). CONCLUSIONS: Cleavage stage embryos with greater mitotic activity perform as well as or better than intermediate or slower cleaving embryos. Rapidly cleaving embryos have high rates of euploidy and significant clinical potential.

Parental chromosomal heteromorphisms are not associated with an increased risk of embryo aneuploidy.

OBJECTIVE: Although chromosomal heteromorphisms are commonly found in the general population, some researchers have suggested a correlation with higher rates of embryo aneuploidy. This study aimed to assess the rates of embryo aneuploidy in couples who carry a chromosome heteromorphism. METHODS: The study included couples who had G-banding karyotype testing and underwent an IVF/PGT-A cycle between January 2012 and March 2018. The participants were classified by couple karyotype: Group A: ≥1 patient reported to be a heterochromatic variant carrier; Group B: both partners reported to be "normal". We assessed the rates of aneuploidy among the groups. We ran a multivariate regression analysis to assess the relationship between heterochromatic variants and the rates of embryo aneuploidy. RESULTS: Of the 946 couples analyzed, 48 (5.0%) reported being a carrier of ≥1 heterochromatic variant. We had 869 IVF/PGT-A cycles included in the analysis (Group A: n=48; Group B: n=82). There were no significant differences in embryo ploidy rates among the groups. The heterochromatic chromosome variant was not associated with increased likelihoods of aneuploidy (OR=1.04, CI:95% 0.85- 1.07; p=0.46). Finally, the gender of the heterochromatic variant carrier had no association with increased likelihood of aneuploidy (OR 1.02, CI 95% 0.81-1.28, p=0.82). CONCLUSIONS: Our study showed no association between parental heterochromatic chromosome variants and subsequent embryo aneuploidy rates. Ploidy rates do not appear to be negatively associated with couples when at least one patient is reported to be a carrier of a heterochromatic variant on the karyotype.

Monozygotic twinning following embryo biopsy at the blastocyst stage.

OBJECTIVE: Monozygotic twinning incidence following preimplantation genetic testing in embryos at cleavage-stage does not appear to increase; however, data regarding the possible impact of the blastocyst-stage preimplantation genetic testing is lacking. We compared the incidence of monozygotic twinning in preimplantation genetic testing cycles performed at the blastocyst-stage, versus cycles without PGT, following single embryo transfer. METHODS: In this retrospective cohort study, we analyzed the incidence of twin pregnancies in patients undergoing intracytoplasmic sperm injection and blastocyst-preimplantation genetic testing (253 cycles), versus a period-matched control population of patients undergoing intracytoplasmic sperm injection and single embryo transfer without preimplantation genetic testing (606 cycles). RESULTS: The overall monozygotic twinning rate was 14/859 (1.6%) per clinical pregnancy. The incidence of zygotic splitting following intracytoplasmic sperm injection and preimplantation genetic testing was 3.5% (95% Confidence interval 1.8%-6.6%) versus 0.8% (95% Confidence interval 0.3%-1.9%) following intracytoplasmic sperm injection without preimplantation sperm injection. After adjusting for potential confounders, preimplantation genetic testing cycles were associated with an increase in the incidence of monozygotic twinning when compared to cycles without embryo biopsy (Odd ratio 3.44, 95% Confidence interval 1.05-11.27, p=0.041). CONCLUSIONS: Our findings indicate that embryo biopsy for preimplantation genetic testing performed at the blastocyst stage is associated to an increase in the incidence of monozygotic twinning. Further validation in larger sample size studies is warranted. Patients undergoing preimplantation genetic testing must receive proper counselling about the potential risks of the technique.

Noninvasive Preimplantation Genetic Testing for Aneuploidy (niPGT-A): The first Brazilian baby.

Recently, a new technology known as the Noninvasive Preimplantation Genetic Testing for Aneuploidy (niPGT-A) emerged, using cell-free DNA present in the spent culture media of human blastocysts. Unlike PGT-A, in which only trophectoderm cells are used, niPGT-A reflects the ploidy state of these cells and internal cell mass, suggesting that this new technology may be less prone to error, being more reliable than the invasive test. The aim of the present study was to report the first occurrence of childbirth following niPGT-A in Brazil.

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.

Birth of healthy neonate following preimplantation genetic diagnosis in a mother with mosaic Turner syndrome. Case report and review of the literature / Recién nacido sano después de diagnóstico genético preimplantatorio en una madre con síndrome de turner mosaico. reporte de caso y revisión de la literatura

RESUMEN Objetivos: 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. Materiales y métodos: 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 preimplan-tatorio 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, SciE- LO y Oxford Journals, con los siguientes términos: "Turner Syndrome", "Mosaic Turner", "Preim- plantation 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 em- brionaria 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. Conclusión: 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.

ABSTRACT Objectives: 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. Materials and 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 data- bases 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. Conclusion: Patients with mosaic Turner syndrome could benefit from preimplantation biopsy and genetic analysis to prevent transmission of the genetic defect to their progeny.

A Novel Predictive Model to Estimate the Number of Mature Oocytes Required for Obtaining at Least One Euploid Blastocyst for Transfer in Couples Undergoing in vitro Fertilization/Intracytoplasmic Sperm Injection: The ART Calculator.

The POSEIDON group (Patient-Oriented Strategies Encompassing IndividualizeD Oocyte Number) has introduced "the ability to retrieve the number of oocytes needed to achieve at least one euploid embryo for transfer" as an intermediate marker of successful outcome in IVF/ICSI cycles. This study aimed to develop a novel calculator to predict the POSEIDON marker. We analyzed clinical and embryonic data of infertile couples who underwent IVF/ICSI with the intention to have trophectoderm biopsy for preimplantation genetic testing for aneuploidy. We used the negative binomial distribution to model the number of euploid blastocysts and the adaptive LASSO (Least Absolute Shrinkage and Selection Operator) method for variable selection. The fitted model selected female age, sperm source used for ICSI, and the number of mature (metaphase II) oocytes as predictors (p < 0.0001). Female age was the most important factor for predicting the probability of a blastocyst being euploid given each mature oocyte (loglikelihood of age [adjusted for sperm source]: 30.9; df = 2; p < 0.0001). The final predictive model was developed using logistic regression analysis, and internally validated by the holdout method. The predictive ability of the model was assessed by the ROC curve, which resulted in an area under the curve of 0.716. Using the final model and mathematical equations, we calculated the individualized probability of blastocyst euploidy per mature retrieved oocyte and the minimum number of mature oocytes required to obtain ≥1 euploid blastocyst-with their 95% confidence interval [CI]-for different probabilities of success. The estimated predicted probabilities of a mature oocyte turn into a euploid blastocyst decreased progressively with female age and was negatively modulated overall by use of testicular sperm across age (p < 0.001). A calculator was developed to make two types of predictions automatically, one using pretreatment information to estimate the minimum number of mature oocytes to achieve ≥1 euploid blastocyst, and another based on the actual number of mature oocytes collected/accumulated to estimate the chances of having a euploid blastocyst using that oocyte cohort for IVF/ICSI. The new ART calculator may assist in clinical counseling and individualized treatment planning regarding the number of oocytes required for at least one euploid blastocyst in IVF/ICSI procedures.

Preimplantation genetic testing for monogenic diseases: a Brazilian IVF centre experience.

OBJECTIVE: To describe the cases of preimplantation genetic testing for monogenic diseases (PGT-M) in fertile couples who had undergone intracytoplasmic sperm injection (ICSI) cycles in a Brazilian in vitro fertilisation (IVF) centre and determine whether these cases were different from those reported from the European Society of Human Reproduction and Embryology (ESHRE). METHODS: This retrospective collection included data obtained from ICSI-PGT-M cycles between 2011 and 2016. The disease indication, number of biopsied embryos, biopsy stage, diagnosed and affected embryos, and cycles with embryo to transfer as well as implantation, pregnancy and miscarriage rates were analysed and compared to cycles without genetic diagnosis (PGT) and with ESHRE PGD Consortium collection XIV-XV. RESULTS: From 5,070 cycles performed, 72 had indications for PGT-M. The most common time for biopsy was cleavage-stage; 93% of the embryos had a diagnostic result, 59.4% of which were genetically transferable, resulting in 68% of the cycles with transferred embryos, a 22.1% implantation rate, and a 28.6% pregnancy rate. No differences in clinical outcomes of cycles with PGT-M or without PGT were observed. The day of biopsy and diagnostic success as well as implantation, pregnancy and miscarriage rates were similar to ESHRE collection. CONCLUSIONS: Although the proportion of cases with PGT-M was low, its efficacy was similar to what was reported in the European collection and represents a viable alternative for families at risk of transmitting a genetic disorder to their offspring. The main difference between our and ESHRE collection were the disease indications, which reflected the admixed, multi-ethnic Brazilian population.

Validation of ART Calculator for Predicting the Number of Metaphase II Oocytes Required for Obtaining at Least One Euploid Blastocyst for Transfer in Couples Undergoing in vitro Fertilization/Intracytoplasmic Sperm Injection.

This multicenter study evaluated the reliability of the recently published ART calculator for predicting the minimum number of metaphase II (MII) oocytes (MIImin) to obtain at least one euploid blastocyst in patients undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). We used clinical and embryonic retrospective data of 1,464 consecutive infertile couples who underwent IVF/ICSI with the intention to have preimplantation genetic testing for aneuploidy. The validation procedure followed a stepwise approach. Firstly, we assessed the distribution of euploid blastocysts per patient and found that it followed a negative binomial distribution. Secondly, we used generalized linear models and applied the Lasso procedure-including MII oocytes to adjust the data-to select the factors predicting the response variable "euploid blastocyst." Third, a logistic regression model-fit to the binomial response euploid (yes/no) for each MII oocyte-was built using the relevant factors. The observational unit was the "woman" whereas the response was the pair (m, n), where n is the number of retrieved MII oocytes and m the corresponding number of euploid blastocysts. The model was internally validated by randomly splitting the data into training and validation sets. The R-squares (~0.25) and the area under the ROC curve (~0.70) did not differ between the training and validation datasets. Fourth, mathematical equations and the calculated probabilities generated by the validation model were used to determine the MIImin required for obtaining at least one euploid blastocyst according to different success probabilities. Lastly, we compared the fittings generated by the validation model and the ART calculator and assessed the predictive value of the latter using the validation dataset. The fittings were sufficiently close for both the estimated probabilities of blastocyst euploid per MII oocyte (r = 0.91) and MIImin (r = 0.88). The ART calculator positive predictive values, i.e., the frequency of patients with at least one euploid blastocyst among those who achieved the estimated MIImin, were 84.8%, 87.5%, and 90.0% for 70%, 80%, and 90% predicted probabilities of success, respectively. The ART calculator effectively predicts the MIImin needed to achieve at least one euploid blastocyst in individual patients undergoing IVF/ICSI. The prediction tool might be used for counseling and planning IVF/ICSI treatments.

The impact of balanced reciprocal translocation - 46,XX,t(7;17) (p13;q24) probably involving the SOX9 gene in the in vitro fertilization with own oocytes evaluated by preimplantation genetic testing or donated oocytes.

Preimplantation genetic testing (PGT) for in vitro fertilization (IVF) - also known as PGT for Structural Rearrangements (PGT-SR) - has emerged as an option for at-risk couples carrying balanced translocations. The female in the couple featured in this case report is a carrier of a balanced reciprocal translocation who underwent IVF. PGT showed all her embryos were aneuploid. She subsequently had two cycles using donor oocytes, which ended in miscarriages.