A Strength, Weaknesses, Opportunities and Threats analysis on time lapse.

PURPOSE OF REVIEW: The study of embryonic development through conventional microscopy has contributed significantly to the success of IVF. However, clinical pregnancy rates per transfer remain as low as 30% according to the latest records of European society if human reproduction and society if assisted reproduction. Considering the increased need to reduce the number of multiple pregnancies, the embryologist is required to improve embryo selection methods to reduce the number of embryos transferred and identify those with the highest implantation potential. This represents a big challenge considering that applying this strategy could jeopardize the overall success rates. New strategies have been proposed including the use of time-lapse systems among others. Although this technology has been used for a decade in IVF labs controversies still exist regarding its potential to substitute conventional morphology for embryo evaluation. RECENT FINDINGS: Lately, different algorithms have been developed correlating embryo kinetics to blastocyst formation, implantation potential, chromosomal content and live birth rate. Moreover, automation and the use of artificial intelligence have recently been introduced to improve this technology. SUMMARY: The present review describes the time-lapse technology and the models available, using a Strength, Weaknesses, Opportunities and Threats analysis based on the clinical experience and published data since 2010.

¿Los parámetros morfocinéticos permiten predecir las aneuploidías embrionarias? / Do morphokinetic parameters allow the prediction of embryo aneuploidy?

ANTECEDENTES: La selección embrionaria sigue siendo uno de los grandes retos de la embriología para poder realizar más transferencias de un único embrión y mejorar los resultados de los tratamientos. Las aneuploidías son una de las principales causas que limitan las probabilidades de éxito, pero las técnicas disponibles actualmente para su diagnóstico son invasivas y costosas. El desarrollo de nuevos métodos precisos y no invasivos basados en parámetros morfocinéticos para detectarlas puede ser muy útil. OBJETIVOS: Revisar estudios relevantes que analicen la relación entre los parámetros morfocinéticos y las aneuploidías y el potencial de éstos para predecirlas. MATERIAL Y MÉTODO: Búsqueda en Pubmed utilizando palabras relacionadas con la morfología, la morfocinética y las aneuploidías embrionarias. También se han revisado las referencias de los artículos más relevantes y trabajos presentados en congresos internacionales celebrados recientemente. RESULTADOS: Numerosos estudios han analizado la capacidad de los parámetros morfocinéticos para detectar aneuploidías embrionarias. Algunos grupos han encontrado correlaciones significativas entre la ploidía y el tiempo de desaparición de los pronúcleos, los tiempos de diferentes divisiones celulares tempranas o parámetros más tardíos, como la duración de la compactación o el inicio de la blastulación. A partir de estos hallazgos, se han desarrollado modelos para clasificar los embriones según el riesgo de aneuploidía. Sin embargo, otros estudios no han encontrado ninguna correlación estadísticamente significativa y los resultados todavía son controvertidos. CONCLUSIONES: Ninguno de los parámetros morfocinéticos analizados proporciona suficiente precisión para diagnosticar aneuploidías embrionarias en las pacientes en las que está indicado realizar diagnóstico genético preimplantacional. Las diferencias entre los grupos pueden deberse al tipo de pacientes incluido y/o a las distintas técnicas utilizadas en cada laboratorio. Es necesario realizar más estudios que aclaren esta relación. Los parámetros morfocinéticos pueden, en determinados casos, ayudar a seleccionar embriones con mayor probabilidad de ser euploides, pero hoy en día la única forma fiable de hacer este diagnóstico es a través del diagnóstico genético preimplantacional. Ámbito: embriología. DISEÑO: revisión bibliográfica

BACKGROUND: Embryo selection still remains one of the great challenges in embryology in order to perform more single embryo transfers and improve clinical outcomes. Aneuploidy is one of the major causes of IVF failure, but the techniques applied for assessing embryo ploidy today are still invasive and expensive. New accurate non-invasive methods to select chromosomally normal embryos based on morphokinetic parameters can become useful. OBJECTIVES: To review relevant studies analysing the relationship between embryo morphokinetics and aneuploidy and the potential of these parameters to predict ploidy. MATERIAL AND METHOD: Search of Pubmed using keywords related to morphology, morphokinetics and embryo aneuploidy. References of the most relevant articles and communications presented in recent international meetings have also been reviewed. RESULTS: Numerous studies have analysed the ability of morphokinetic parameters to detect embryo aneuploidy. Some groups have found significant correlations between ploidy and timing of pronuclei fading, timing of early mitotic divisions as well as later morphologic events, such as the duration of compaction and the time of initiation of blastulation. Based on these results, different models have been developed to categorize the risk of aneuploidy in embryos. However, other studies have not found any statistically significant correlation and the results are still controversial. CONCLUSIONS: None of the morphokinetic parameters analysed is accurate enough to detect embryo aneuploidy in patients indicated for preimplantation genetic screening. Differences between groups may be due to the patient's populations included and/or variations in the techniques applied. Further studies are needed to clarify the possible relation. Morphokinetic parameters can aid in certain cases, to select embryos with higher probability of being euploid. However, preimplantation genetic screening still remains the only reliable technique to do such analysis. SETTING: embryology. DESIGN: review

Type of chromosome abnormality affects embryo morphology dynamics.

OBJECTIVE: To study the differences in the cleavage time between types of embryo chromosomal abnormalities and elaborate algorithm to exclude aneuploid embryos according to the likelihood to be euploid. DESIGN: Retrospective cohort study. SETTING: University affiliated private center. PATIENT(S): Preimplantational genetic screening patients (n = 112) including cases of advanced maternal age, repeated implantation failure, and recurrent miscarriage. A total of 485 embryos were analyzed. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): All biopsied embryos were cultured in an incubator with time-lapse technology, cleavage timing from insemination to day 3 and all kinetic parameters that have been described in previous studies by our group. RESULT(S): Logistic regression analysis were used to identify morphokinetic parameters and some were strongly associated with complex aneuploid embryos; t3 (odds ratio = 0.590, 95% confidence interval 0.359-0.971) and t5-t2 (odds ratio = 0.151, 95% confidence interval 0.082-0.278). CONCLUSION(S): Embryo morphokinetics are affected by chromosome aneuploidy and further analysis of the chromosome content reveals higher differences when the complexity in the chromosome disorders is increased. The use of time-lapse monitoring, although not able to detect an abnormal embryo, may be potentially useful to discard those embryos with high risk of complex chromosomal abnormalities.

The state of "freeze-for-all" in human ARTs.

The recent development of vitrification technologies and the good outcomes obtained in assisted reproduction technologies have supported new indications for freezing and segmentation of treatment. Beyond OHSS prevention and avoidance of embryo transfers in the setting of an adverse endocrinological profile or endometrial cavity, we have witnessed a trend to shift fresh embryo transfers to frozen embryo transfers in many programs. We critically review the available evidence and suggest that freeze-all is not "for all," but should be individualized.

Automatic time-lapse instrument is superior to single-point morphology observation for selecting viable embryos: retrospective study in oocyte donation.

OBJECTIVE: To correlate the different categories provided by a commercial diagnostic test with blastocyst formation, quality, implantation potential, and ongoing pregnancy (OPR) for the purpose of validating the automatic annotations and the classification algorithm. DESIGN: Observational, retrospective, multicenter cohort study. SETTING: University-affiliated private IVF center. PATIENT(S): A total of 3,002 embryos, including 521 transferred embryos with known implantation, from 626 IVF cycles that were incubated in a conventional incubator and monitored with an automatic time-lapse test. INTERVENTIONS(S): None. MAIN OUTCOME MEASURE(S): Embryo selection was based on morphology and the classification provided by a commercial diagnostic test. Implantation was the primary end point, and OPR, blastocyst formation (BR), and embryo morphology were secondary end points. RESULT(S): BR and number of optimal blastocysts were related to the classification test. This correlation was also observed when analyzing implantation rates (day 3 transfer: high 38.2%, medium 31.7% and low 26.1%; day 5 transfer: high 66.7%, medium 50%, low 31%). Patients where no high embryos were transferred (n = 75) had an OPR of 46.70%, and those patients where at least one high embryo was transferred (n = 109) significantly increased OPR to 67%. A logistic regression analysis studying other confounding factors (day of transfer, number of oocytes obtained, and embryo morphology classification) was included. In that model, if at least one of the embryos was labeled as high, OPR was 2.567 times higher than a cycle where no high embryos were transferred. CONCLUSION(S): Our study presents, to our knowledge, the largest set of transferred embryos after time-lapse analysis with the use of an automatic time-lapse test. The provided classification was related to reproductive outcome. Our results suggest that the automated embryo diagnostic test provided extra information to the embryologist to select the best embryos, independently from clinical features of the patient or day of transfer.

What does morphokinetics add to embryo selection and in-vitro fertilization outcomes?

PURPOSE OF REVIEW: Time lapse technology represents a new tool in the in-vitro fertilization (IVF) laboratory. It can aid the embryologist in the detection of objective and quantifiable markers associated with embryo viability and implantation. The purpose of this review is to explain how embryo morphokinetics can be used as an adjunct to standard morphological assessment and to evaluate its potential value to improve IVF outcomes. RECENT FINDINGS: Several algorithms have been developed. Some utilize early kinetic markers, whereas others rely more on later stages of embryo development. Even though over a handful of randomized control trials are in progress, at this point, only one has been published demonstrating a significant increase in implantation rates and ongoing pregnancy rates when selecting embryos on the basis of a combination of morphological assessment and morphokinetics. SUMMARY: We believe that standard morphological assessment should remain the gold standard to initiate embryo evaluation; however, if possible, it can be complemented with the use of morphokinetics. This new approach will allow the embryologist to perform a more accurate and objective embryo selection and therefore reduce the number of embryos transferred while maintaining or even improving clinical results.

Increasing the probability of selecting chromosomally normal embryos by time-lapse morphokinetics analysis.

OBJECTIVE: To study the differences in the cleavage time between chromosomally normal and abnormal embryos and to elaborate an algorithm to increase the probability of noninvasively selecting chromosomally normal embryos. DESIGN: Retrospective cohort study. SETTING: University-affiliated infertility center. PATIENT(S): Preimplantation genetic screening patients (n = 125; n = 77 with ET), including cases of repeated implantation failure or recurrent miscarriage. A total of 504 embryos were analyzed. INTERVENTION(S): Embryo culture within a time-lapse system. MAIN OUTCOME MEASURE(S): Kinetic variables included the time to 2 (t2), 3 (t3), 4 (t4), and 5 (t5) cells as well as the length of the second (cc2 = t3 - t2) and third (cc3 = t5 - t3) cell cycle, the synchrony in the division from 2 to 4 cells (s2 = t4 - t3), and the interval t5 - t2. Implantation and clinical pregnancy rates were also analyzed. RESULT(S): A logistic regression analysis identified t5 - t2 (odds ratio [OR] = 2.853; 95% confidence interval [CI], 1.763-4.616), followed by cc3 (OR = 2.095; 95% CI, 1.356-3.238) as the most relevant variables related to normal chromosomal content. On the basis of these results, an algorithm for embryo selection is proposed to classify embryos from A to D. Each category exhibited significant differences in the percentage of normal embryos (A, 35.9%; B, 26.4%; C, 12.1%; D, 9.8%). CONCLUSION(S): Chromosomally normal and abnormal embryos have different kinetic behavior. On the basis of these differences, the proposed algorithm serves as a tool to classify embryos and to increase the probability of noninvasively selecting normal embryos.

Type of culture media does not affect embryo kinetics: a time-lapse analysis of sibling oocytes.

STUDY QUESTION: Are the morphokinetics of growing embryos affected by the type of culture media utilized? SUMMARY ANSWER: Morphokinetic parameters used for embryo selection are not affected between the two different concept culture media analyzed. WHAT IS KNOWN ALREADY: Studies on the effect of culture media on human embryos have focused on evaluating different in-house and commercially available media as well as comparing outcomes among different commercial media. Nonetheless, the evaluation of embryo development in these studies was based on static observations and very little is known from a dynamic point of view. STUDY DESIGN, SIZE, DURATION: Prospective cohort study, October 2010 and April 2011. PARTICIPANTS/MATERIALS, SETTING, METHODS: University-affiliated infertility center. Patients undergoing egg donation (n = 75) in which embryos were cultured with two different types of media in a time-lapse system. Embryo development was analyzed with time-lapse imaging for single step media (Global®) and sequential media (Sage® Cleavage). Variables studied included the timing to two cells (t2), three cells (t3), four cells (t4) and five cells (t5) as well as the length of the second cell cycle (cc2 = t3 - t2) and the synchrony in the division from two to four cells (s2 = t4 - t3). Implantation and clinical pregnancy rates were also analyzed. MAIN RESULTS AND THE ROLE OF CHANCE: No statistically significant differences were observed between the two media for all the variables analyzed. When analyzing the percentage of embryos falling within the optimal ranges proposed for s2, cc2 and t5, we did not find significant differences between the two media. Pregnancy and implantation rates were similar for the three types of transfers: 48.0% (CI 95% 28.4-67.6) and 42.0% (CI 95% 22.5-61.4) with Global media; 58.8% (CI 95% 35.4-82.2) and 38.2% (CI 95% 15.0-61.4) with Cleavage media; and 58.1% (CI 95% 40.7-75.4) and 37.1% (CI 95% 22.1-52.1) with mixed transferred, respectively. Multiple implantations (twins) were also similar among the three groups, with 24.0% (CI 95% 9.3-45.1) for transfers with embryos cultured in Global media, 17.6% (CI 95% 3.7-43.3) for transfers with embryos cultured in Cleavage media and 22.5% (CI 95% 9.5-41.0) with mixed transfers. LIMITATIONS, REASONS FOR CAUTION: The study was not powered to test differences in pregnancy rates between the two culture media, as this was not the hypothesis tested. Results are based on observations with embryos from oocyte donors and need to be repeated with embryos from infertile patients of different ages. WIDER IMPLICATIONS OF THE FINDINGS: The absence of differences in morphokinetics between two different media concepts validates the algorithm for embryo selection in diverse culture conditions. STUDY FUNDING/COMPETING INTEREST(S): No specific funding was obtained for this study; it was solely funded by IVI. None of the authors have any economic affiliation with Unisense Fertilitech A/S but IVI is a minor shareholder in Unisense Fertilitech A/S.

Embryo incubation and selection in a time-lapse monitoring system improves pregnancy outcome compared with a standard incubator: a retrospective cohort study.

OBJECTIVE: To quantify the effect on reproductive outcome of culturing and selecting embryos using a novel time-lapse monitoring system (TMS). DESIGN: Retrospective observational cohort study. SETTING: University-affiliated private center. PATIENT(S): Donation and autologous intracytoplasmic sperm injection (ICSI) cycles from ten IVF clinics using similar procedures, cultured in TMS (n = 1,390) or in a standard incubator (SI; n = 5,915). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Clinical pregnancy rate confirmed by ultrasound in week 7. RESULT(S): A logistic regression analysis, which included all significant confounding factors, was used to evaluate the effect of culturing and selecting embryos with the use of TMS. Comparing clinical pregnancy rates per oocyte retrieval with TMS and SI treatments gave a crude effect of odds ratio [OR] 1.190 (95% confidence interval [CI] 1.058-1.337). Oocyte source, maternal age, day of transfer, and number of retrieved oocytes were identified as significant confounding factors. After accounting for confounding factors, the effect of TMS culture was OR 1.201 (95% CI 1.059-1.363). Limiting analysis to treatments with embryo transfer and including number of transferred embryos as a confounding factor likewise gave a significant effect of TMS with OR 1.157 (95% CI 1.018-1.315). CONCLUSION(S): Analysis of retrospective data indicated that culturing and selecting embryos by TMS significantly improved the relative probability of clinical pregnancy (+20.1% per oocyte retrieval, +15.7% per embryo transfer). The elevated clinical pregnancy rate was attributed to a combination of stable culture conditions and the use of morphokinetic parameters for embryo selection.

Novel syntaxin 11 gene (STX11) mutation in three Argentinean patients with hemophagocytic lymphohistiocytosis.

INTRODUCTION: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease with major diagnostic and therapeutic difficulties, basically comprising two different conditions: primary and secondary forms. Recent advances regarding molecular diagnosis may be useful to distinguish from one another, especially in sporadic cases starting in early infancy. MATERIALS AND METHODS: In this report, we evaluated three Argentinean patients with clinical suspicion of HLH, but without family history. We excluded mutations in the perforin gene but identified in the three patients a novel homozygous deletion (c. 581_584delTGCC; p.Leu194ProfsX2) in the gene-encoding syntaxin 11 (STX11), causing a premature termination codon. RESULTS AND CONCLUSION: Each parent from the three unrelated families resulted heterozygous for this deletion confirming the diagnosis of familial hemophagocytic lymphohistiocytosis type 4. Patients shared the same single-nucleotide polymorphism profile in STX11 gene, and genotyping at ten microsatellites surrounding this gene support the presence of a single-haplotype block carrying the novel mutation.

Clinical and molecular analysis of 49 patients with X-linked agammaglobulinemia from a single center in Argentina.

INTRODUCTION: Argentina has a large number of patients with definite diagnosis of X-linked agammaglobulinemia reported in the Latin-American registry. Forty-nine of them were seen in our referral pediatric hospital, between 1987 and 2005. RESULTS AND DISCUSSION: A retrospective study of clinical, laboratory, and molecular data showed that respiratory tract infections were the most frequent initial clinical presentation and the most common among all manifestations prior to diagnosis (69%). Up to diagnosis, we found a high frequency of severe infections (sepsis, 14% and meningitis, 16%) and a high proportion of patients with chronic lung disease. During follow-up, the development of chronic lung disease was significantly related with age at diagnosis and inappropriate treatment. CONCLUSION: Although molecular diagnosis has been available in our center for the past 10 years, there is no doubt that awareness for early recognition of immunodeficiency should be improved through broader and more comprehensive education programs emphasizing characteristics of patients with immunodeficiencies.