Blastocysts from partial compaction morulae are not defined by their early mistakes.

RESEARCH QUESTION: Is partial compaction during morula formation associated with an embryo's developmental ability and implantation potential? DESIGN: Retrospective analysis of data from 196 preimplantation genetic testing for aneuploidy (PGT-A) cycles. Embryos starting compaction were grouped according to the inclusion or not of all the blastomeres in the forming morula (full compaction or partial compaction). The possible effect of maternal age and ovarian response on compaction was analysed. Morphokinetic characteristics, blastocyst formation rate, morphology and cytogenetic constitution of the obtained blastocysts were compared. Comparisons of reproductive outcomes after the transfer of euploid blastocysts from both groups were established. Finally, in a subset of embryos, the chromosomal constitution concordance of the abandoned cells and the corresponding blastocyst through trophectoderm biopsies was assessed. RESULTS: A total of 430 embryos failed to include at least one cell during compaction (partial compaction group [49.3%]), whereas the 442 remaining embryos formed a fully compacted morula (full compaction group [50.7%]). Neither female age nor the number of oocytes collected affected the prevalence of partial compaction morulae. Morphokinetic parameters were altered in embryos from partial compaction morulae compared with full compaction. Although an impairment in blastocyst formation rate was observed in partial compaction morulae (57.2% versus 70.8%, P < 0.001), both chromosomal constitution (euploidy rate: partial compaction [38.4%] versus full compaction [34.2%]) and reproductive outcomes (live birth rate: partial compaction [51.9%] versus full compaction [46.2%]) of the obtained blastocysts were equivalent between groups. A high ploidy correlation of excluded cells-trophectoderm duos was observed. CONCLUSIONS: Partial compaction morulae show a reduced developmental ability compared with full compaction morulae. Resulting blastocysts from both groups, however, have similar euploidy rates and reproductive outcomes. Cell exclusion might be a consequence of a compromised embryo development regardless of the chromosomal constitution of the excluded cells.

Do reproductive history and information given through genetic counselling influence patients' decisions on mosaic embryo transfer?

OBJECTIVE: To assess patients' and embryonic characteristics that may have an influence on the decision to transfer a mosaic embryo. METHOD: Single centre retrospective cohort study including 1247 PGT-A cycles. Demographic and clinical factors associated with a decision to transfer a mosaic embryo were studied. Female age, number of previous cycles, previous availability of euploid embryos, history of miscarriages and parity as well as percentage of mosaicism, type of anomaly and chromosome risk were studied in relation to decision-making. Outcomes after mosaic embryo transfer were assessed. RESULTS: To date, in 7.9% of cycles (99/1247), patients have had to make a decision on the fate of their mosaic embryos. In 23.2% of cycles (23/99), patients decided to transfer. In most cases (79.8%; 79/99), patients underwent genetic counselling before the decision. None of the variables analysed were associated with the patients' decision, although parity and the high-degree mosaicism (>50%) seemed to be negatively associated with the decision to transfer (18.2% vs. 29.8%, p = 0.294; 10% vs. 32.2%, p = 0.052). CONCLUSIONS: Neither reproductive history nor information on mosaic embryo characteristics through counselling seems to be determinative for patients when deciding to transfer a mosaic embryo. Promising and increasing data on clinical outcomes after mosaic embryo transfer will be of utmost importance to soften risk perception regarding mosaic embryos and give a better, simplified and more evidence-based counselling.

Male and female blastocysts: any difference other than the sex?

RESEARCH QUESTION: Is there any imbalance in the sex ratio at the blastocyst stage of human embryos? And what is the sex ratio in euploid, transferred, implanted blastocysts and at birth? DESIGN: Embryos from 646 women undergoing 921 preimplantation genetic testing for aneuploidy (PGT-A) cycles from September 2017 to February 2020 were included. Data from the chromosomal constitution of 2637 biopsied blastocysts were retrospectively analysed. Trophectoderm samples were analysed by next-generation sequencing. Embryos were categorized as euploid, mosaic or aneuploid. A total of 548 blastocysts diagnosed as euploid were warmed and transferred in a subsequent single-embryo transfer cycle. RESULTS: The blastocyst sex ratio was skewed in favour of male sex with 53.1% (1401/2637) of blastocysts diagnosed as male and 46.9% (1236/2637) as female (sex ratio 1.13, 95% confidence interval [CI] 1.05-1.22). Following biopsy and PGT-A, 41.2% (1086/2637) of blastocysts were classified as euploid, 7.7% (202/2637) as mosaic and 51.2% (1349/2637) as aneuploid. More chromosome euploidy was observed among female than male blastocysts (adjusted odds ratio 1.29, 95% CI 1.08-1.55) after adjusting for female age, male age and gonadotrophin dose. Euploid blastocysts were comparable between the sexes (sex ratio 0.99, 95% CI 0.88-1.11). No significant differences were observed between the sexes in implantation (sex ratio 0.86, 95% CI 0.68-1.08), miscarriage (sex ratio 1, 95% CI 0.51-1.97) or live birth rate (sex ratio 0.85, 95% CI 0.66-1.08). CONCLUSIONS: More male than female embryos develop to the blastocyst stage. Male blastocysts exhibit a higher aneuploidy rate. The capacity to implant and lead to a live birth is similar between the sexes.

The effect of trophectoderm biopsy technique and sample handling on artefactual mosaicism.

PURPOSE: To determine whether embryo mosaicism prevalence in preimplantation genetic testing for aneuploidy (PGT-A) cycles is associated with the trophectoderm biopsy technique used (a. number of laser pulses or b. the use of flicking or pulling) or the time to tubing. METHODS: Prospective observational study performed in a single IVF-PGT-A setting from May 2019 to May 2021. Trophectoderm biopsies were analysed by next-generation sequencing. Mosaicism was analysed in relation to the biopsy methodology (number of laser pulses and pulling vs flicking), time elapsed from biopsy to tubing (min), and time of sample cryostorage from tubing to amplification (days). As a secondary objective, the number of laser pulses and biopsy methodology were studied in relation to clinical outcomes of transferred euploid blastocysts. RESULTS: None of the analysed variables were associated to mosaicism prevalence. Multivariable regression analysis demonstrated that mosaicism prevalence was comparable either when  > 3 laser pulses were used as compared to ≤ 3 (13.9% vs 13.8%, aOR = 0.8726 [0.60-1.28]) and pulling compared to flicking (13.1% vs 14.0%, aOR = 0.86 [0.60-1.23]). Moreover, neither the number of laser pulses during biopsy (> 3 vs ≤ 3) nor the technique used (pulling vs flicking) were associated with clinical pregnancy after the transfer of frozen-thawed euploid blastocysts (54.9% vs 55.2%, aOR = 1.05 [0.53-2.09]; 61.1% vs 52.9%, aOR = 1.11 [0.55-2.25], respectively). CONCLUSION: Our results suggest that, as long as the biopsy and tubing procedures are performed following standardized high quality procedures, no specific approach would increase the generation of artefactual mosaicism as a result of trophectoderm biopsy. Trophectoderm biopsies should be performed regardless of the methodology but always aiming on minimising blastocyst manipulation.

Prevalence, types and possible factors influencing mosaicism in IVF blastocysts: results from a single setting.

RESEARCH QUESTION: Are intrinsic or extrinsic factors associated with embryo mosaicism prevalence in IVF cycles? DESIGN: Retrospective cohort study of preimplantation genetic testing for aneuploidy (PGT-A) cycles carried out at a university-affiliated IVF clinic between October 2017 and October 2019. Trophectoderm biopsies were analysed by next generation sequencing. Mosaicism prevalence, type of anomaly and the chromosomes involved were analysed. Intrinsic and extrinsic factors potentially inducing mosaicism were studied: maternal and paternal age, antral follicle count, cumulus-oocyte complexes retrieved, female body mass index, PGT-A indication, sperm concentration, total dosage of gonadotrophins, embryo quality and day of blastocyst formation, single-step commercial media used and biopsy operator. RESULTS: Overall prevalence of mosaicism in our PGT-A setting was 13.9%. In segmental mosaicism, larger chromosomes tended to be more affected, which was not observed in whole-chromosome mosaicism. Additionally, segmental mosaicism was mostly observed in monosomy (69.6%; P < 0.01) compared with whole-chromosome mosaicism (49.7% monosomies versus 50.3% trisomies; P = 0.83). Although a high inter-patient variability was observed, only paternal age showed a positive association with mosaicism (adjusted OR 1.26, 95% CI 1.02 to 1.54) among the analysed variables. CONCLUSIONS: Our results suggest remarkable differences in the mechanisms generating segmental and whole-chromosome mosaicism, indicating that they may deserve different consideration when studying them and when prioritizing them for transfer. Male factor seems to be associated with mosaicism and may be worthy of specific assessment in future studies.

Morphokinetics and in vitro developmental potential of monopronucleated ICSI zygotes until the blastocyst stage.

The aim of this study was to provide a more comprehensive understanding of 1PN intracytoplasmic sperm injection (ICSI) zygotes. To achieve this objective, we assessed whether all 1PN-derived embryos showed a similar morphokinetic pattern, and if the morphokinetic behaviour of 1PN-derived embryos was comparable with that of 2PN-derived embryos. In total, 149 1PN ICSI zygotes (study group) and 195 2PN ICSI zygotes (control group) were included in the study. Embryo development potential was evaluated in terms of blastocyst rate. Morphokinetic parameters, including the pronucleus diameter and kinetics of in vitro development, were also analyzed. Embryos derived from 1PN ICSI zygotes showed impaired development compared with 2PN-derived embryos, with blastocyst rates of 28.9% and 67.2%, respectively. The diameter of the pronucleus of 1PN zygotes was larger than that of 2PN zygotes. When compared with 2PN-derived embryos, those derived from 1PN zygotes had a visible pronucleus for a shorter time, in addition to a longer syngamy time and slower kinetic behaviour from two to nine cells. When 1PN-derived blastocysts and 2PN-derived blastocysts were compared, the developmental kinetics were similar in both groups, except for a delayed and longer duration of the compaction phase in 1PN-derived embryos. In conclusion, monopronucleated ICSI zygotes present differences in developmental capacity and morphokinetic behaviour compared with 2PN ICSI zygotes, showing particular morphokinetic parameters related to pronucleus formation. Only the 1PN ICSI-derived embryos that reached the blastocyst stage have similar morphokinetic development to blastocysts from 2PN zygotes.

Deconstructing the myth of poor prognosis for fast-cleaving embryos on day 3. Is it time to change the consensus?

PURPOSE: To determine the developmental competence of fast-cleaving D3 embryos. METHODS: Retrospective study including 4028 embryos from 513 PGT-A cycles performed between July 2014 and June 2017. Embryos were cultured in time-lapse incubators and biopsied at blastocyst stage. Embryos were classified in groups according to the number of cells on D3 (from 2-cell to ≥13 -cell and compacted). A generalized linear mixed model adjusted for confounding factors was performed to assess the chance to give rise to an euploid blastocyst in each group compared with the chance of 8-cell embryos. Implantation and live birth rates were also analyzed. RESULTS: The statistical analysis showed that embryos with 9 to 11 cells had a slightly lower euploid blastocyst rate than 8-cell embryos (OR (95% CI) 0.77 (0.61-0.96)) while embryos with more than 11 cells were found to be just as likely to give rise to an euploid blastocyst as the 8-cell embryos (OR (95% CI) 1.20 (0.92-1.56)). Conversely, slow-cleaving embryos had a significantly lower euploid blastocyst rate than 8-cell embryos (OR (95% CI) 0.31 (0.24-0.39)). Moreover, euploid blastocysts derived from fast-cleaving embryos and from 8-cell embryos exhibit similar live birth rates. No significant differences were found in the chance to give rise a live birth between 8-cell and 9- to 11-cell embryos (OR (95% CI) 1.23 (0.70-2.15)) and > 11-cell embryos (OR (95% CI) 1.09 (0.57-2.09)). CONCLUSIONS: Embryos with more than 11 cells exhibit similar developmental competence to 8-cell embryos. Their poor prognosis should be reconsidered.

Inconclusive results in preimplantation genetic testing: go for a second biopsy?

The transition in biopsy timing from blastomere to trophectoderm biopsy has led to a remarkable decrease in the percentage of undiagnosed blastocysts. However, patients with few or no euploid blastocysts can be affected by this residual percentage of diagnosis failure. The aim of this study is to assess whether blastocyst rebiopsy and revitrification is an efficient and safe procedure to be applied in cases of no results after analysis. Fifty-three patients agreed to the warming of 61 blastocysts to perform a second biopsy and PGT-A by aCGH. Only 75.4% of the blastocysts survived, reexpanded, and could be rebiopsied. After the second biopsy and analysis, 95.6% of the blastocysts were successfully diagnosed with an euploidy rate of 65.9%. Eighteen euploid blastocysts were warmed and transferred to 18 patients with a 100% survival and reexpansion rate. Seven clinical pregnancies have been achieved with 4 live births, 1 ongoing pregnancy, and 2 miscarriages. Thus, although few transfers of rebiopsied and revitrified blastocysts have been performed till date, our preliminary results show that this approach is efficient and safe to be applied for undiagnosed blastocysts, as it ultimately allows the transfer of euploid blastocysts and good clinical outcomes.

Transition from blastomere to trophectoderm biopsy: comparing two preimplantation genetic testing for aneuploidies strategies.

SummaryShortly after the implementation of comprehensive chromosome screening (CCS) techniques for preimplantation genetic testing for aneuploidies (PGT-A), the discussion about the transition from day 3 to blastocyst stage biopsy was initiated. Trophectoderm biopsy with CCS is meant to overcome the limitations of cleavage-stage biopsy and single-cell analysis. The aim of this study was to assess the results obtained in our PGT-A programme after the implementation of this new strategy. Comparisons between the results obtained in 179 PGT-A cycles with day 3 biopsy (D+3) and fresh embryo transfer, and 204 cycles with trophectoderm biopsy and deferred (frozen-thawed) embryo transfer were established. Fewer embryos were biopsied and a higher euploidy rate was observed in the trophectoderm biopsy group. No differences in implantation (50.3% vs. 61.4%) and clinical pregnancy rate per transfer (56.1% vs. 65.3%) were found. Although the mean number of euploid embryos per cycle did not differ between groups (1.5 ± 1.7 vs. 1.7 ± 1.8), the final number of euploid blastocysts available for transfer per cycle was significantly higher in the trophectoderm biopsy group (1.1 ± 1.3 vs. 1.7 ± 1.8). This factor led to an increased cumulative live birth rate in this last group (34.1% vs. 44.6%). Although both strategies can offer good results, trophectoderm biopsy offers a more robust diagnosis and the intervention is less harmful for the embryos so more euploid blastocysts are finally available for transfer and/or vitrification.

Reliability and agreement on embryo assessment: 5 years of an external quality control programme.

An external quality-control programme for morphology-based embryo quality assessment, incorporating a standardized embryo grading scheme, was evaluated over a period of 5 years to determine levels of inter-observer reliability and agreement between practising clinical embryologists at IVF centres and the opinions of a panel of experts. Following Guidelines for Reporting Reliability and Agreement Studies, the Gwet index and proportion of positive (Ppos) and negative agreement were calculated. For embryo morphology assessment, a substantial degree of reliability was measured between the centres and the panel of experts (Gwet index: 0.76; 95% CI 0.70 to 0.84). The agreement was higher for good- versus poor-quality embryos. When multinucleation or vacuoles were observed, low levels of reliability were obtained (Ppos: 0.56 and 0.43, respectively). In blastocysts, the characteristic that presented the largest discrepancy was that related to the inner cell mass. In decisions about the final disposition of the embryo, reliability between centre and the panel of experts was moderate (Gwet index: 0.51; 95% CI 0.41 to 0.60). In conclusion, the ability of clinical embryologists to evaluate the presence of multinucleation and vacuoles in the early cleavage embryo, and to determine the category of the inner cell mass in blastocysts, needs to be improved.

Chromosomal analysis of blastocyst derived from monopronucleated ICSI zygotes: approach by double trophectoderm biopsy.

OBJECTIVE: This study aims to increase the knowledge about monopronucleated ICSI-derived blastocysts, analyzing trophectoderm biopsies by aCGH and FISH to evaluate their chromosome constitution. METHODS: Fifteen monopronucleated ICSI-derived blastocysts were studied. Double trophectoderm biopsy was performed and analyzed by FISH and aCGH. The blastocysts were classified according to chromosome constitution. Disagreements between the two techniques were assessed. RESULTS: Results obtained after FISH and aCGH analyses showed the following: 20% (3/15) and 60% (9/15) diploid females, respectively; 26.7% (4/15) and 26.7% (4/15) diploid males, respectively; and 53.3% (8/15) and 13.3% (2/15) mosaics, respectively. No mosaic male embryos were found using FISH or aCGH. There were disagreements in 40% (6/15) of the cases due to the higher detection of mosaicism by FISH compared to aCGH. CONCLUSIONS: The combination of FISH and aCGH has been shown to be a suitable approach to increase the knowledge about monopronucleated ICSI-derived embryos. FISH analysis of blastocysts derived from monopronucleated ICSI zygotes enabled us to conclude that aCGH underestimates haploidy. Some diploid embryos diagnosed by aCGH are in fact mosaic. In cases where these embryos would be used for reproductive purposes, extra analysis of parental genome origin is recommended.

Selecting embryos with the highest implantation potential using data mining and decision tree based on classical embryo morphology and morphokinetics.

PURPOSE: The objective of this work was to determine which embryonic morphokinetic parameters up to D3 of in vitro development have predictive value for implantation for the selection of embryos for transfer in clinical practice based upon information generated from embryo transfers with known implantation data (KID). METHODS: A total of 800 KID embryos (100% implantation rate (IR) per transfer and 0% IR per transfer) cultured in an incubator with Time-Lapse system were retrospectively analysed. Of them, 140 embryos implanted, whereas 660 did not. RESULTS: The analysis of morphokinetic parameters, together with the embryo morphology assessment on D3, enabled us to develop a hierarchical model that places the classical morphological score, the t4 and t8 morphokinetic values, as the variables with the best prognosis of implantation. CONCLUSION: In our decision tree, the classical morphological score is the most predictive parameter. Among embryos with better morphological scores, morphokinetics permits deselection of embryos with the lowest implantation potential.

La edición genómica aplicada a seres humanos: aspectos éticos, jurídicos y sociales / No disponible

El artículo analiza las implicaciones éticas jurídicas y sociales del empleo de las técnicas de edición genómica en seres humanos y su capacidad para alterar el genoma de la descendencia. Examina su impacto en investigación básica, asi como su potencial en el uso terapéutico y en el llamado mejoramiento humano. El trabajo parte de la evidencia científica y técnica para profundizar en los valores implicados en las diferentes opciones y cursos de acción, y .previo estudio de los argumentos que la doctrina esgrime en la actualidad. proponer recomendaciones para encauzar el debate y orientar las actuaciones en este campo

The article analyzes the ethical, legal and social issues of gene editing techniques applied to human beings and their ability to alter the genome of offspring. It also examines the impact of the current application of these techniques on basic research, its therapeutic potential and the socalled human enhancement. The work starts from the scientific and technical evidence to deepen the values involved in the different options and courses of action. After studying the arguments that the doctrine currently argues, the goal is to propose a series of recommendations in order to orient the debate and possible actions in the field

NGS-Based Assay for the Identification of Individuals Carrying Recessive Genetic Mutations in Reproductive Medicine.

Next-generation sequencing (NGS) has the capacity of carrier screening in gamete donation (GD) programs. We have developed and validated an NGS carrier-screening test (qCarrier test) that includes 200 genes associated with 368 disorders (277 autosomal recessive and 37 X-linked). Carrier screening is performed on oocyte donation candidates and the male partner of oocyte recipient. Carriers of X-linked conditions are excluded from the GD program, whereas donors are chosen who do not carry mutations for the same gene/disease as the recipients. The validation phase showed a high sensitivity (>99% sensitivity) detecting all single-nucleotide variants, 13 indels, and 25 copy-number variants included in the validation set. A total of 1,301 individuals were analysed with the qCarrier test, including 483 candidate oocyte donors and 635 receptor couples, 105 females receiving sperm donation, and 39 couples seeking pregnancy. We identified 56% of individuals who are carriers for at least one genetic condition and 1.7% of female donors who were excluded from the program due to a carrier state of X-linked conditions. Globally, 3% of a priori assigned donations had a high reproductive risk that could be minimized after testing. Genetic counselling at different stages is essential for helping to facilitate a successful and healthy pregnancy.

Comprehensive preimplantation genetic screening and sperm deoxyribonucleic acid fragmentation from three males carrying balanced chromosome rearrangements.

OBJECTIVE: To assess whether preimplantation genetic screening can successfully identify cytogenetically normal embryos in couples carrying balanced chromosome rearrangements in addition to increased sperm DNA fragmentation. DESIGN: Comprehensive preimplantation genetic screening was performed on three couples carrying chromosome rearrangements. Sperm DNA fragmentation was assessed for each patient. SETTING: Academic center. PATIENT(S): One couple with the male partner carrying a chromosome 2 pericentric inversion and two couples with the male partners carrying a Robertsonian translocation (13:14 and 14:21, respectively). INTERVENTION(S): A single blastomere from each of the 18 cleavage-stage embryos obtained was analysed by metaphase comparative genomic hybridization. Single- and double-strand sperm DNA fragmentation was determined by the alkaline and neutral Comet assays. MAIN OUTCOME MEASURE(S): Single- and double-strand sperm DNA fragmentation values and incidence of chromosome imbalances in the blastomeres were analyzed. RESULT(S): The obtained values of single-strand sperm DNA fragmentation were between 47% and 59%, and the double-strand sperm DNA fragmentation values were between 43% and 54%. No euploid embryos were observed in the couple showing the highest single-strand sperm DNA fragmentation. However, euploid embryos were observed in the other two couples: embryo transfer was performed, and pregnancy was achieved by the couple showing the lowest sperm DNA fragmentation values. CONCLUSION(S): Preimplantation genetic screening enables the detection of euploid embryos in couples affected by balanced chromosome rearrangements and increased sperm DNA fragmentation. Even though sperm DNA fragmentation may potentially have clinical consequences on fertility, comprehensive preimplantation genetic screening allows for the identification and transfer of euploid embryos.

Is it justified to transfer two embryos in oocyte donation? A pilot randomized clinical trial.

Multiple pregnancies involve high obstetric and perinatal risks. The aim of this study is to evaluate, in a pilot randomized control study, if the cumulative pregnancy and live birth rates of elective single embryo transfer (eSET) are comparable to the ones obtained with elective double embryo transfer (eDET). A total of 65 patients with at least two good quality embryos was randomized, 34 (52.3%) assigned to the eSET group and 31 (47.7%) to the eDET group. The cumulative pregnancy rates (eSET: 73.5% and eDET: 77.4%. RR: 0.95 95% CI: 0.72-1.25) and live birth rates (eSET: 58.8% and eDET: 61.3%. RR: 0.96 95% CI: 0.64-1.42) were similar in the two groups. The twin pregnancy rate in the fresh transfers of eDET group was 47.7% and 0% in the eSET group. The medical team decided to interrupt the study for reasons related to risks associated with elevated twin pregnancy rate, leaving low numbers of patients within the study as a result. When considering cumulative success rates, eSET and eDET are similar in terms of efficacy. However, eDET involves an increased and unacceptable twin pregnancy rate. The only prevention strategy is single embryo transfer.

Oligonucleotide arrays vs. metaphase-comparative genomic hybridisation and BAC arrays for single-cell analysis: first applications to preimplantation genetic diagnosis for Robertsonian translocation carriers.

Comprehensive chromosome analysis techniques such as metaphase-Comparative Genomic Hybridisation (CGH) and array-CGH are available for single-cell analysis. However, while metaphase-CGH and BAC array-CGH have been widely used for Preimplantation Genetic Diagnosis, oligonucleotide array-CGH has not been used in an extensive way. A comparison between oligonucleotide array-CGH and metaphase-CGH has been performed analysing 15 single fibroblasts from aneuploid cell-lines and 18 single blastomeres from human cleavage-stage embryos. Afterwards, oligonucleotide array-CGH and BAC array-CGH were also compared analysing 16 single blastomeres from human cleavage-stage embryos. All three comprehensive analysis techniques provided broadly similar cytogenetic profiles; however, non-identical profiles appeared when extensive aneuploidies were present in a cell. Both array techniques provided an optimised analysis procedure and a higher resolution than metaphase-CGH. Moreover, oligonucleotide array-CGH was able to define extra segmental imbalances in 14.7% of the blastomeres and it better determined the specific unbalanced chromosome regions due to a higher resolution of the technique (≈ 20 kb). Applicability of oligonucleotide array-CGH for Preimplantation Genetic Diagnosis has been demonstrated in two cases of Robertsonian translocation carriers 45,XY,der(13;14)(q10;q10). Transfer of euploid embryos was performed in both cases and pregnancy was achieved by one of the couples. This is the first time that an oligonucleotide array-CGH approach has been successfully applied to Preimplantation Genetic Diagnosis for balanced chromosome rearrangement carriers.

Live birth using vitrified--warmed oocytes in invasive ovarian cancer: case report and literature review.

This article reports the live birth of a healthy newborn using vitrified-warmed oocytes in a young patient with invasive mucinous ovarian carcinoma (stage Ic). Diagnosis was performed after a laparoscopic left adnexectomy. She underwent two cycles of ovarian stimulation, and 14 oocytes were vitrified before fertility-sparing surgery with uterus preservation went ahead. One year later, a transfer of two embryos was performed after insemination of warmed oocytes. Eighteen days after the transfer, she underwent a laparotomy because of abdominal pain, vaginal bleeding and haemoperitoneum. A right cornual ectopic pregnancy in the uterus was diagnosed and a wedge resection was performed to resolve it. One week later, a viable intrauterine pregnancy was confirmed under ultrasound. An elective Caesarean section was performed at week 38 of gestation, resulting in the birth of a healthy boy weighing 2650 g. As far as is known, this is the first live birth reported through vitrified-warmed oocytes in a patient with invasive ovarian cancer. Although oocyte vitrification is an alternative to be considered for fertility preservation in highly selected cases of ovarian cancer, controversial issues are discussed. Fertility preservation is a proven possibility in some cancer patients according to their age, disease and time available until the beginning of their oncological treatment. Although oocyte vitrification is an alternative to be considered for fertility preservation in highly selected cases of ovarian cancer, no live birth has been reported. We report the live birth of a healthy newborn through vitrified-warmed oocytes in a young patient with invasive mucinous ovarian carcinoma (stage Ic). Diagnosis was performed after a laparoscopic left adnexectomy. She underwent two cycles of ovarian stimulation, and 14 oocytes were vitrified before fertility-sparing surgery with uterus preservation went ahead. One year later, a transfer of two embryos was performed after the insemination of the warmed oocytes. Eighteen days after the transfer she underwent a laparotomy because of abdominal pain, vaginal bleeding and haemoperitoneum. A right cornual ectopic pregnancy in the uterus was diagnosed and a wedge resection was performed to resolve it. One week later, a viable intrauterine pregnancy was confirmed under ultrasound. An elective Caesarean section was performed at week 38 of gestation, resulting in the birth of a healthy boy weighing 2650 g. To our knowledge, this is the first live birth reported using vitrified-warmed oocytes in invasive ovarian cancer. Controversial issues are reviewed and discussed.

Transexualidad y reproducción: situación actual desde el punto de vista clínico y legal / Transsexualism and reproduction: Clinical and legal situation

Se diagnostican como transexuales las personas que se identifican con el sexo opuesto y rechazan el género propio. Existen distintas hipótesis que intentan explicar el origen de la transexualidad, siendo las más aceptadas las teorías con bases biológicas. La prevalencia estimada es variable en función de la zona geográfica, siendo más frecuentes los transexuales femeninos que los masculinos. Las técnicas de reproducción asistida facilitan las opciones reproductivas de este colectivo que acude, cada vez más, a los centros clínicos especializados para tratar de formar una familia defendiendo el derecho a la reproducción de todo ser humano. Los transexuales pueden verse favorecidos especialmente por las técnicas de preservación de la fertilidad, pudiendo criopreservar sus gametos antes de la reasignación de sexo como estrategia preventiva en vistas a un posible deseo de reproducción futura. La falta de recomendaciones o guías consensuadas sobre la aplicabilidad de las técnicas de reproducción asistida en individuos transexuales y el vacío normativo existente dificultan su acceso a estas técnicas. Esta revisión recoge las posibles opciones reproductivas de los transexuales desde un punto de vista clínico y analiza la situación actual en el marco de la legislación española vigente (AU)

People who identify themselves with the opposite sex and reject their own gender are diagnosed as transsexuals. Different hypotheses have tried to explain the origin of transsexualism, biological theories being the most accepted. The estimated prevalence is variable, this depending on the geographic area. Female are more frequent than male transsexuals. Assisted reproduction techniques facilitate the reproductive options of this group who increasingly come to specialized clinical centers to try to form a family, defending the reproductive rights of every human being. Transsexuals could be especially favored by fertility preservation techniques, being able to cryopreserve their gametes before sex reassignment as a preventive strategy in view of a possible desire for future reproduction. Lack of recommendations or agreed on guidelines and absence of regulations about the applicability of assisted reproduction in transsexuals hinders their access to these techniques. This review summarizes the possible reproductive options of transsexuals from a clinical point of view and analyzes the current situation in the framework of Spanish law (AU)

Investigations into implantation failure in oocyte-donation recipients.

In recent decades, the Western world has been experiencing a societal trend to prioritize the professional careers of women who postpone motherhood to about 40 years of age, when, unfortunately, natural reproductive potential declines. This is the reason why these women increasingly find it necessary to resort to oocyte donation to have a child. Thanks to the young age of the donors, the efficacy of oocyte donation is the highest of all assisted reproduction treatments and pregnancy rates achieved with this technique exceed 50%. Moreover, the large registries from ESHRE and ASRM show live birth rates close to this figure. However, there are patients who experience repeated failures in several oocyte-donation cycles, and so far oocyte-donation repeated implantation failure has not been clearly defined. This study analysed the results obtained from 2531 oocyte-donation cycles carried out in 1990 patients and defines oocyte-donation repeated implantation failure as failure to implant with more than two embryo transfers and more than four high-grade embryos transferred. This study observed this condition in 140 oocyte recipients (7%). Also, oocyte cohort size, uterine factors and systemic thrombophilias as important aetiological factors were identified were to offer new therapeutic strategies to patients.