Successful preimplantation genetic testing for fibrodysplasia ossificans progressiva: a case report.

PURPOSE OF THE STUDY: Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant condition that leads to significant disability and morbidity, characterised by the formation of heterotopic hard tissues within connective tissues. The condition has an incidence of approximately one per two million people worldwide. There is no known single effective treatment available for FOP. We report the world's first case of a healthy infant born following in vitro fertilisation (IVF) and preimplantation genetic testing for monogenic disorder (PGT-M) using Karyomapping for FOP. CASE PRESENTATION: A 30-year-old Caucasian female with FOP presented with her partner seeking IVF with PGT-M to achieve a healthy pregnancy with an embryo unaffected by FOP. METHODS: The couple underwent IVF and PGT-M using Karyomapping as the testing method. A multi-disciplinary team approach was utilised in planning this case, considering the additional risks of oocyte retrieval, pregnancy and childbirth in women with FOP. MAIN FINDINGS: The oocyte retrieval was covered with a 5-day course of prednisolone to reduce the risk of a localised inflammatory reaction, which could result in subsequent heterotopic ossification. This was subsequently weaned down with reducing doses every two days. The patient underwent uncomplicated oocyte retrieval, yielding 12 mature oocytes. Following intracytoplasmic sperm injection (ICSI), ten zygotes having two pro-nuclei were cultured, and six underwent trophoectoderm biopsy and vitrification 5-6 days after retrieval. PGT-M via Karyomapping revealed four out of six (66.7%) of blastocysts were not carriers of the maternal high-risk FOP allele. In total, the patient had three separate embryo transfers. Pregnancy was achieved following the third frozen embryo transfer, which went to 37 weeks' gestation, and delivered by Caesarean section. The baby was born in excellent condition and is unaffected by FOP. CONCLUSION: IVF/ICSI and PGT-M using Karyomapping was successfully implemented to identify embryos carrying the high-risk FOP allele resulting in a healthy livebirth.

Discovery of Pyridopyrimidinones that Selectively Inhibit the H1047R PI3Kα Mutant Protein.

The H1047R mutation of PIK3CA is highly prevalent in breast cancers and other solid tumors. Selectively targeting PI3KαH1047R over PI3KαWT is crucial due to the role that PI3KαWT plays in normal cellular processes, including glucose homeostasis. Currently, only one PI3KαH1047R-selective inhibitor has progressed into clinical trials, while three pan mutant (H1047R, H1047L, H1047Y, E542K, and E545K) selective PI3Kα inhibitors have also reached the clinical stage. Herein, we report the design and discovery of a series of pyridopyrimidinones that inhibit PI3KαH1047R with high selectivity over PI3KαWT, resulting in the discovery of compound 17. When dosed in the HCC1954 tumor model in mice, 17 provided tumor regressions and a clear pharmacodynamic response. X-ray cocrystal structures from several PI3Kα inhibitors were obtained, revealing three distinct binding modes within PI3KαH1047R including a previously reported cryptic pocket in the C-terminus of the kinase domain wherein we observe a ligand-induced interaction with Arg1047.

AAV gene therapy in companion dogs with severe hemophilia: Real-world long-term data on immunogenicity, efficacy, and quality of life.

The hemophilias are the most common severe inherited bleeding disorders and are caused by deficiency of clotting factor (F) VIII (hemophilia A) or FIX (hemophilia B). The resultant bleeding predisposition significantly increases morbidity and mortality. The ability to improve the bleeding phenotype with modest increases in clotting factor levels has enabled the development and regulatory approval of adeno-associated viral (AAV) vector gene therapies for people with hemophilia A and B. The canine hemophilia model has proven to be one of the best predictors of therapeutic response in humans. Here, we report long-term follow-up of 12 companion dogs with severe hemophilia that were treated in a real-world setting with AAV gene therapy. Despite more baseline bleeding than in research dogs, companion dogs demonstrated a 94% decrease in bleeding rates and 61% improvement in quality of life over a median of 4.1 years (range 2.6-8.9). No new anti-transgene immune responses were detected; one dog with a pre-existing anti-FVIII inhibitor achieved immune tolerance with gene therapy. Two dogs expressing 1%-5% FVIII post gene therapy experienced fatal bleeding events. These data suggest AAV liver-directed gene therapy is efficacious in a real-world setting but should target expression >5% and closely monitor those with levels in the 1%-5% range.

Discovery of Five SOS2 Fragment Hits with Binding Modes Determined by SOS2 X-Ray Cocrystallography.

SOS1 and SOS2 are guanine nucleotide exchange factors that mediate RTK-stimulated RAS activation. Selective SOS1:KRAS PPI inhibitors are currently under clinical investigation, whereas there are no reports to date of SOS2:KRAS PPI inhibitors. SOS2 activity is implicated in MAPK rebound when divergent SOS1 mutant cell lines are treated with the SOS1 inhibitor BI-3406; therefore, SOS2:KRAS inhibitors are of therapeutic interest. In this report, we detail a fragment-based screening strategy to identify X-ray cocrystal structures of five diverse fragment hits bound to SOS2.

Analysis of vector genome integrations in multicentric lymphoma after AAV gene therapy in a severe hemophilia A dog.

Adeno-associated viral (AAV) vectors have traditionally been viewed as predominantly nonintegrating, with limited concerns for oncogenesis. However, accumulating preclinical data have shown that AAV vectors integrate more often than previously appreciated, with the potential for genotoxicity. To understand the consequences of AAV vector integration, vigilance for rare genotoxic events after vector administration is essential. Here, we investigate the development of multicentric lymphoma in a privately owned dog, PC9, with severe hemophilia A that was treated with an AAV8 vector encapsidating a B domain-deleted canine coagulation F8 gene. PC9 developed an aggressive B cell lineage multicentric lymphoma 3.5 years after AAV treatment. Postmortem analysis of the liver, spleen, and lymph nodes showed the expected biodistribution of the AAV genome. Integration events were found both in PC9 and a second privately owned hemophilia A dog treated similarly with canine F8 gene transfer, which died of a bleeding event without evidence of malignancy. However, we found no evidence of expanded clones harboring a single integration event, indicating that AAV genome integrations were unlikely to have contributed to PC9's cancer. These findings suggest AAV integrations occur but are mostly not genotoxic and support the safety profile of AAV gene therapy.

INvestigational Study Into Transplantation of the Uterus (INSITU): a cross-sectional survey among women with uterine factor infertility in the UK assessing background, motivations and suitability.

IMPORTANCE: The study summarises the selection prescreen criteria currently used in the UK for a uterus transplant and highlights the number of women who are suitable to proceed. OBJECTIVES: To assess the demographics, motivations, reasons and suitability among women with absolute uterine factor infertility (AUFI) to undergo uterine transplantation (UTx). DESIGN: A cross-sectional survey. SETTING: An electronic questionnaire was sent via email to women with AUFI who had previously been referred to the UTx research team or approached the Womb Transplant UK Charity. The questions assessed suitability to undergo UTx based on demographic information, perceptions to adoption and surrogacy and reasons why UTx was preferable. Responses were assessed against the study selection criteria. PARTICIPANTS: Women with AUFI. RESULTS: 210 women completed the questionnaire. The most common aetiology of AUFI in our cohort was Mayer-Rokitansky-Küster-Hauser (68%; n=143) whereas 29% (n=62) had previously undergone hysterectomy. 63% (n=132) of the cohort had previously considered adoption, 5% (n=11) had attempted it and 2 (1%) had successfully adopted. The most common reason cited to undergo UTx over adoption was to experience gestation (n=63; 53%), while 37% (n=44) wanted a biologically related child. 76% (n=160) of participants had previously considered surrogacy, 22 (10%) had attempted it and 2 (1%) had successfully become mothers using a surrogate. The most common reason to undergo UTx over surrogacy was to experience gestation (n=77; 54%). 15% (n=21) were concerned about the legal implications, 14% (n=20) identified the financial cost as a barrier and 8% (n=12) could not consider it due to religious reasons. On adhering to the selection criteria, 65 (31%) women were suitable to proceed with the trial. CONCLUSION: The study demonstrates that implementing commonly used selection criteria for a UTx led to an attrition rate of more than two-thirds of women who requested to initially undergo the process. As more studies present outcomes following UTx, critical assessment of the selection criteria currently used is warranted to ensure potential recipients are not being unnecessarily excluded. TRIAL REGISTRATION NUMBER: NCT02388802.

Immunotherapy targeting B cells and long-lived plasma cells effectively eliminates pre-existing donor-specific allo-antibodies.

Pre-existing anti-human leukocyte antigen (HLA) allo-antibodies constitute a major barrier to transplantation. Current desensitization approaches fail due to ineffective depletion of allo-specific memory B cells (Bmems) and long-lived plasma cells (LLPCs). We evaluate the efficacy of chimeric antigen receptor (CAR) T cells targeting CD19 and B cell maturation antigen (BCMA) to eliminate allo-antibodies in a skin pre-sensitized murine model of islet allo-transplantation. We find that treatment of allo-sensitized hosts with CAR T cells targeting Bmems and LLPCs eliminates donor-specific allo-antibodies (DSAs) and mitigates hyperacute rejection of subsequent islet allografts. We then assess the clinical efficacy of the CAR T therapy for desensitization in patients with multiple myeloma (MM) with pre-existing HLA allo-antibodies who were treated with the combination of CART-BCMA and CART-19 (ClinicalTrials.gov: NCT03549442) and observe clinically meaningful allo-antibody reduction. These findings provide logical rationale for clinical evaluation of CAR T-based immunotherapy in highly sensitized candidates to promote successful transplantation.

Combining Surface-Induced Dissociation and Charge Detection Mass Spectrometry to Reveal the Native Topology of Heterogeneous Protein Complexes.

Charge detection mass spectrometry (CDMS) enables the direct mass measurement of heterogeneous samples on the megadalton scale, as the charge state for a single ion is determined simultaneously with the mass-to-charge ratio (m/z). Surface-induced dissociation (SID) is an effective activation method to dissociate non-intertwined, non-covalent protein complexes without extensive gas-phase restructuring, producing various subcomplexes reflective of the native protein topology. Here, we demonstrate that using CDMS after SID on an Orbitrap platform offers subunit connectivity, topology, proteoform information, and relative interfacial strengths of the intact macromolecular assemblies. SID dissects the capsids (∼3.7 MDa) of adeno-associated viruses (AAVs) into trimer-containing fragments (3mer, 6mer, 9mer, 15mer, etc.) that can be detected by the individual ion mass spectrometry (I2MS) approach on Orbitrap instruments. SID coupled to CDMS provides unique structural insights into heterogeneous assemblies that are not readily obtained by traditional MS measurements.

Systematic review and meta-analysis: does pre-implantation genetic testing for aneuploidy at the blastocyst stage improve live birth rate?

PURPOSE: To establish if preimplantation genetic testing for aneuploidy (PGT-A) at the blastocyst stage improves the composite outcome of live birth rate and ongoing pregnancy rate per embryo transfer compared to conventional morphological assessment. METHODS: A systematic literature search was conducted using PubMed, EMBASE and Cochrane database from 1st March 2000 until 1st March 2022. Studies comparing reproductive outcomes following in vitro fertilisation using comprehensive chromosome screening (CCS) at the blastocyst stage with traditional morphological methods were evaluated. RESULTS: Of the 1307 citations identified, six randomised control trials (RCTs) and ten cohort studies fulfilled the inclusion criteria. The pooled data identified a benefit between PGT-A and control groups in the composite outcome of live birth rate and ongoing pregnancy per embryo transfer in both the RCT (RR 1.09, 95% CI 1.02-1.16) and cohort studies (RR 1.50, 95% CI 1.28-1.76). Euploid embryos identified by CCS were more likely to be successfully implanted amongst the RCT (RR 1.20, 95% CI 1.10-1.31) and cohort (RR 1.69, 95% CI 1.29-2.21) studies. The rate of miscarriage per clinical pregnancy is also significantly lower when CCS is implemented (RCT: RR 0.73, 95% CI 0.56-0.96 and cohort: RR 0.48, 95% CI 0.32-0.72). CONCLUSIONS: CCS-based PGT-A at the blastocyst biopsy stage increases the composite outcome of live births and ongoing pregnancies per embryo transfer and reduces the rate of miscarriage compared to morphological assessment alone. In view of the limited number of studies included and the variation in methodology between studies, future reviews and analyses are required to confirm these findings.

Fertility preservation and realignment in transgender women.

Medical care for transgender people is multi-faceted and attention to individual reproductive aspirations and planning are an essential, yet often overlooked aspect of care. Given the impact of hormonal therapy and other gender affirmation procedures on reproductive function, extensive counselling and consideration of fertility preservation is recommended prior to their commencement. This review article explores the reproductive aspirations of transgender women and considers the current disparity between stated desires regarding utilisation of fertility preservation services. Current fertility preservation options and prospective treatments currently showing promise in the research arena are explored.

Adeno-Associated Virus Gene Therapy for Hemophilia.

In vivo gene therapy is rapidly emerging as a new therapeutic paradigm for monogenic disorders. For almost three decades, hemophilia A (HA) and hemophilia B (HB) have served as model disorders for the development of gene therapy. This effort is soon to bear fruit with completed pivotal adeno-associated viral (AAV) vector gene addition trials reporting encouraging results and regulatory approval widely anticipated in the near future for the current generation of HA and HB AAV vectors. Here we review the clinical development of AAV gene therapy for HA and HB and examine outstanding questions that have recently emerged from AAV clinical trials for hemophilia and other monogenic disorders.

Indocyanine Green Is a Safe and Effective Alternative to Radioisotope in Breast Cancer Sentinel Lymph Node Biopsy regardless of Patient Body Mass Index.

INTRODUCTION: A recent meta-analysis [Lancet Oncol. 2010;11:908-909] has confirmed high sensitivity of indocyanine green (ICG) fluorescence mapping for sentinel node detection in early breast cancer. Concerns have previously been raised regarding the efficacy in patients with high body mass index (BMI). MATERIALS AND METHODS: All consecutive patients undergoing sentinel lymph node biopsies (SLNBs) for early breast cancer in NHS Tayside were included in a prospective audit of surgical and pathology findings. All patients included in the study received dual injection of patent blue dye and ICG. Approval was obtained from the local Caldicott guardian for collection and use of personal data. RESULTS: Of 239 cases, all were female patients of mean age 62 years (range 27-93). In 4.2% (10/239) of cases, neither blue dye nor ICG was present in the axilla. Of the remaining 229 SLNB cases in this series, surgeons documented retrieval of 451 nodes, with a mean surgical nodal count per case of 1.97 (range 1-5) and pathological nodal count of 2.15 (range 0-7). Eighty three cases were performed in patients with BMI 30-39.9 and 21 cases with BMI ≥40, with nodal detection rates of 96.4% (80/83) and 95.2% (20/21), respectively, in these groups of patients. Twenty percent (48/229) of cases had nodal metastases on histopathology. CONCLUSIONS: This is a large single-center study which demonstrates the safety and accuracy of the combined ICG and blue dye technique for SLNB in breast cancer. This is represented by nodal detection rates and node positivity rates which are comparable to previous multicenter studies of standard SLNB regardless of BMI.

A dedicated robotic bedside physician assistant significantly enhances trainee console operating time in general thoracic surgery.

Objective: As trainees rotate through thoracic subspecialties within their curricula, a crucial portion of their robotic training consists of actual console operating time. The more time spent on the surgeon console, the greater the development will be through the course of their training. Implementing a physician assistant at the bedside may increase the operative console time for the trainee and develop robotic skills in a more expeditious rate. The objective was to evaluate the impact a designated robotic physician assistant can have on trainee console learning opportunity. Methods: Operating room data collected consisted of all robotic general thoracic surgical cases that trainees participated in with and without a physician assistant present. Metrics regarding case efficiency included anesthesia ready-to-incision, incision-to-console, and raw resident console times. By using PRISM software, a nonparametric t test was used to analyze each averaged data group compared between when a physician assistant was present and not present. Results: The mean resident console time without and with a physician assistant assist was 45.8 minutes and 80.9 minutes, respectively (P < .0001). The average portion of a case performed by a trainee similarly without and with a physician assistant present was 28.0% and 77.1%, respectively (P < .0001). Case efficiency metrics between physician assistant presence cohorts showed no difference. Conclusions: Thoracic surgical trainees have increased opportunity for robotic skill development within a fellowship or resident program curriculum when a designated robotic physician assistant is present in the operating room. These findings are significant for the improvement of residency and fellowship robotic training models moving forward by incorporating robotic-specialized physician assistants in academic institutions.

Reproductive outcomes from ten years of elective oocyte cryopreservation.

RESEARCH QUESTION: To assess the relationship between the number of oocytes retrieved during elective oocyte cryopreservation (EOC) cycles with various clinical, biochemical, and radiological markers, including age, body mass index (BMI), baseline anti-Müllerian hormone (AMH), antral follicle count (AFC), Oestradiol level (E2) and total number of follicles ≥ 12 mm on the day of trigger. To also report the reproductive outcomes from women who underwent EOC. METHODS: A retrospective cohort of 373 women embarking on EOC and autologous oocyte thaw cycles between 2008 and 2018 from a single London clinic in the United Kingdom. RESULTS: 483 stimulation cycles were undertaken amongst 373 women. The median (range) age at cryopreservation was 38 (26-47) years old. The median numbers of oocytes retrieved per cycle was 8 (0-37) and the median total oocytes cryopreserved per woman was 8 (0-45). BMI, E2 level and number of follicles ≥ 12 mm at trigger were all significant predictors of oocyte yield. Multivariate analysis confirmed there was no significant relationship between AFC or AMH, whilst on univariate analysis statistical significance was proven. Thirty six women returned to use their cryopreserved oocytes, of which there were 41 autologous oocyte thaw cycles undertaken. There were 12 successful livebirths achieved by 11 women. The overall livebirth rate was 26.8% per cycle. No livebirths were achieved in women who underwent EOC ≥ 40 years old, and 82% of all livebirths were achieved in women who had done so between 36 and 39 years old. CONCLUSION: Clinical, biochemical and radiological markers can predict oocyte yield in EOC cycles. Reproductive outcomes are more favourable when cryopreservation is performed before the age of 36, with lower success rates of livebirth observed in women aged 40 years and above.

Study protocol for a randomised controlled trial on the use of intraoperative ultrasound-guided laparoscopic ovarian cystectomy (UGLOC) as a method of fertility preservation in the management of benign ovarian cysts.

INTRODUCTION: The lifetime risk of women undergoing surgery for the presence of benign ovarian pathology in the UK is 5%-10%. Despite minimally invasive surgical techniques, evidence suggests a number of healthy ovarian follicles and tissues are resected intraoperatively, resulting in subsequent decline of ovarian reserve. As such, there is an increasing demand for the implementation of fertility preservation surgery (FPS). This study will evaluate the effect on ovarian reserve following two different surgical interventions for the management of benign ovarian cysts. METHODS AND ANALYSIS: We will conduct a two-armed randomised controlled trial comparing laparoscopic ovarian cystectomy, considered gold standard treatment as per the Royal College of Obstetricians and Gynaecologists (RCOG) Green Top guidelines for the management of benign ovarian cysts, with ultrasound-guided laparoscopic ovarian cystectomy (UGLOC), a novel method of FPS. The study commencement date was October 2021, with a completion date aimed for October 2024. The primary outcome will be the difference in anti-Müllerian hormone (AMH) (pmol/L) and antral follicle count (AFC) measured 3 and 6 months postoperatively from the preoperative baseline. Secondary outcomes include assessment of various surgical and histopathological findings, including duration of hospital stay (days), duration of surgery (minutes), presence of intraoperative cyst rupture (yes/no), presence of ovarian tissue within the resected specimen (yes/no) and the grade of follicles excised within the specimen (grade 0-4). We aim to randomise 94 patients over 3 years to achieve power of 80% at an alpha level of 0.05. ETHICS AND DISSEMINATION: Findings will be published in peer-reviewed journals and presented at national and international conferences and scientific meetings. The Chelsea NHS Research and Ethics Committee have awarded ethical approval of the study (21/LO/036). TRIAL REGISTRATION NUMBER: NCT05032846.

A comparison of fertility preservation outcomes in patients who froze oocytes, embryos, or ovarian tissue for medically indicated circumstances: a systematic review and meta-analysis.

OBJECTIVE: To compare obstetric outcomes in patients cryopreserving reproductive cells or tissues before gonadotoxic therapy. DESIGN: A literature search was conducted following PRISMA guidelines on Embase, Medline, and Web of Science. Studies reporting obstetric outcomes in cancer patients who completed cryopreservation of oocyte, embryo, or ovarian tissue were included. SETTING: Not applicable. PATIENT(S): Cancer patients attempting pregnancy using cryopreserved cells or tissues frozen before cancer therapy. INTERVENTION(S): Oocyte, embryo, or ovarian tissue cryopreservation for fertility preservation in cancer. MAIN OUTCOME MEASURE(S): The total numbers of clinical pregnancies, live births, and miscarriages in women attempting pregnancy using cryopreserved reproductive cells or tissues were calculated. A meta-analysis determined the effect size of each intervention. RESULT(S): The search returned 4,038 unique entries. Thirty-eight eligible studies were analyzed. The clinical pregnancy rates were 34.9%, 49.0%, and 43.8% for oocyte, embryo, and ovarian tissue cryopreservation, respectively. No significant differences were found among groups. The live birth rates were 25.8%, 35.3%, and 32.3% for oocyte, embryo, and ovarian tissue cryopreservation, respectively, with no significant differences among groups. The miscarriage rates were 9.2%, 16.9%, and 7.5% for oocyte, embryo, and ovarian tissue cryopreservation, respectively. Significantly fewer miscarriages occurred with ovarian tissue cryopreservation than with embryo cryopreservation. CONCLUSION(S): This enquiry is required to counsel cancer patients wishing to preserve fertility. Although the limitations of this study include heterogeneity, lack of quality studies, and low utilization rates, it serves as a starting point for comparison of reproductive and obstetric outcomes in patients returning for family-planning after gonadotoxic therapy.

Fertility Sparing Surgery and Borderline Ovarian Tumours.

To determine the oncological outcomes following fertility-sparing surgery (FSS) for the management of Borderline Ovarian Tumours (BOTs). A retrospective analysis of participants diagnosed with BOTs between January 2004 and December 2020 at the West London Gynaecological Oncology Centre was conducted. A total of 172 women were diagnosed; 52.3% (90/172) underwent FSS and 47.7% (82/172) non-FSS. The overall recurrence rate of disease was 16.9% (29/172), of which 79.3% (23/29) presented as the recurrence of serous or sero-mucinous BOTs and 20.7% (6/29) as low-grade serous carcinoma (LGSC). In the FSS group, the recurrence rate of BOTs was 25.6% (23/90) presenting a median 44.0 (interquartile range (IQR) 41.5) months, of which there were no episodes of recurrence presenting as LGSC reported. In the non-FSS group, all recurrences of disease presented as LGSC, with a rate of 7.7% (6/78), following a median of 47.5 months (IQR 47.8). A significant difference between the type of surgery performed (FSS v Non-FSS) and the association with recurrence of BOT was observed (Pearson Chi-Square: p = 0.000; x = 20.613). Twelve women underwent ultrasound-guided ovarian wedge resection (UGOWR) as a novel method of FSS. Recurrence of BOT was not significantly associated with the type of FSS performed (Pearson Chi- Square: x = 3.166, p = 0.379). Non-FSS is associated with negative oncological outcomes compared to FSS, as evidenced by the higher rate of recurrence of LGSC. This may be attributed to the indefinite long-term follow up with ultrasound surveillance all FSS women undergo, enabling earlier detection and treatment of recurrences.

Live birth rate following a euploid blastocyst transfer is not affected by double vitrification and warming at cleavage or blastocyst stage.

PURPOSE: To compare reproductive outcomes following a euploid embryo transfer, between those embryos vitrified-warmed twice to those vitrified-warmed once. METHODS: We retrospectively analysed 694 single euploid frozen embryo transfer cycles following preimplantation genetic testing for aneuploidy (PGT-A). For cycles in group 1 (N = 451), embryos were biopsied for PGT-A at blastocyst stage and vitrified. For cycles in group 2 (N = 146), embryos were vitrified at blastocyst stage, before being warmed and biopsied for PGT-A and vitrified again. For cycles in group 3 (N = 97), embryos were vitrified on day-3, before being warmed, cultured to day-5 and biopsied for PGT-A and re-vitrified. RESULTS: The pregnancy, clinical pregnancy and livebirth rate in group 2 were not statistically different to group 1 (pregnancy rate, adjusted OR 1.09, 95% CI 0.62-1.91; clinical pregnancy, aOR 0.89, 95% CI 0.58-1.37; live birth rate, aOR 0.85, 95% CI 0.56-1.28). There was also no significant difference between group 3 and group 1, with similar pregnancy rate (aOR 1.22, 95% CI 0.74-1.99), clinical pregnancy rate (aOR 1.21, 95% CI 0.75-1.96) and live birth rate (aOR 1.15, 95% CI, 0.73-1.80). There was no significant difference in miscarriage rates between all three groups. The age at the oocyte collection, embryo quality and day of biopsy were associated with pregnancy, clinical pregnancy and live birth rate. CONCLUSION: This study suggests that vitrifying and warming embryos twice at blastocyst or at cleavage and then blastocyst stage, can lead to similar reproductive outcomes to embryos vitrified-warmed once, after a single euploid embryo transfer.