Time-lapse embryo imaging technology: does it improve the clinical results?

Serum anti-Müllerian hormone concentrations are related to embryo development: lessons from time-lapse imaging

Our objective was to study whether serum anti-Müllerian hormone (AMH) concentrations were associated with embryo morphokinetic events. This retrospective cohort study was performed in a private university-affiliated in vitro fertilization centre between March 2019 and December 2020 and included 902 oocytes cultured in a time-lapse imaging incubator, obtained from 114 intracytoplasmic sperm injection cycles performed. The relationship between AMH concentrations and morphokinetic events was investigated by considering the clustering of data (multiple embryos/patient). Evaluated kinetic markers were time to pronuclei appearance (tPNa) and fading (tPNf), time to two (t2), three (t3), four (t4), five (t5), six (t6), seven (t7), and eight cells (t8), (tSB) and time to the start of blastulation (tSB) and to blastulation (tB). Significant inverse relationships were observed between serum AMH concentrations and tPNf, t3, t4, t5, t6, t7, t8, and tB. The AMH was positively correlated with the KIDScore and implantation rate. Increased serum AMH concentrations correlated with faster embryo development. The clinical implications of this effect on embryo development warrant further investigation.

Time-lapse observation of mouse preimplantation embryos using a simple closed glass capillary method

Time-lapse observation is a popular method for analyzing mammalian preimplantation embryos, but it often requires expensive equipment and skilled techniques. We previously developed a simply and costly embryo-culture system in a sealed tube that does not require a CO2 incubator. In the present study, we developed a new time-lapse observation system using our previous culture method and a glass capillary. Zygotes were placed in a glass capillary and sunk in oil for observation under a stereomicroscope. Warming the capillary using a thermoplate enabled most of the zygotes to develop into blastocysts and produce healthy offspring. This time-lapse observation system captured images every 30 min for up to 5 days, which confirmed that the developmental speed and quality of the embryos were not affected, even with fluorescence. Overall, this new system is a simple time-lapse observation method for preimplantation embryos that does not require dedicated machines and advanced techniques.

Pre-Vitrification and Post-Warming Variables of Vitrified-Warmed Blastocysts That Are Predictable for Implantation

Human IVF embryos that are not used for fresh transfer are cryopreserved by vitrification for later embryo transfers. This study evaluates pre-vitrification and post-warming embryo characteristics that are suitable to predict the chance of clinical pregnancy in single vitrified blastocyst transfer (SVBT) cycles. In a multicenter observational trial (IMBOS trial), embryos were cultured in a time-lapse system before and after vitrification. Associations between clinical pregnancy, morphokinetic parameters, blastocyst collapse, KIDScore D5, pre-vitrification and post-warming Gardner scores, post-warming blastocyst size and re-expansion rates before SVBT were analyzed in 182 SVBTs which resulted in 89 clinical pregnancies. No association was found between clinical pregnancy after SVBT and the number of collapses or the maximal collapse size before vitrification. The multifactorial analysis of pre-vitrification Gardner scores showed a significant association with clinical pregnancy for trophectoderm grading but not for expansion/hatching status and inner cell mass grading. A significant association with clinical pregnancy was found for the time to reach a blastocyst after pronuclear fading (tB-tPNf), KIDScore D5 and post-warming size but not the rate of expansion or maximal expansion size. The selection of blastocysts for SVBT could benefit from using pre-vitrification parameters like tB-tPNf, trophectoderm grading and post-warming blastocyst size.

Prediction of embryo implantation rate using a sole parameter of timing of starting blastulation

A time-lapse monitoring system provides a complete picture of the dynamic embryonic development process and simultaneously supplies extensive morphokinetic data. The objective of this study was to investigate whether the use of the morphokinetic parameter of time of starting blastulation (tSB) can improve the implantation rate of day-5 transferred blastocyst selected based on morphological parameters. In this retrospective study we analyzed the morphokinetics of 196 day-5 transferred blastocysts, selected solely based on morphological parameters. The interval time from intracytoplasmic sperm injection (ICSI) to time of starting blastocyst formation (tSB) was calculated for each embryo. The overall implantation rate of transferred blastocyst, selected based only on morphological parameters, was 49.2%. Implantation rate, determined retrospectively, was significantly higher (58.8% versus 42.6%, P = 0.02) for embryos with a short interval time to tSB (78-95.9 h) compared with embryos with a longer timeframe (96-114 h). Time of expanded blastocyst (tEB) post-ICSI was also significantly associated with implantation; however, this parameter was not available for all the embryos at time of transfer. When we tested only high ranked KIDScore day-3 sub-group embryos, the implantation rate was significantly higher in short interval time embryos compared with longer interval time embryos (62.2% vs. 45.5%, respectively, P = 0.02).These observations emphasize the importance of the timing of starting blastulation over blastocyst morphological parameters and may provide a preferable criterion for good morphology day-5 blastocyst selection.

The Association of Kinetic Variables with Blastocyst Development and Ploidy Status

Background:

Despite a plethora of studies conducted so far, a debate is still unresolved as to whether TLM can identify predictive kinetic biomarkers or algorithms universally applicable. Therefore, this study aimed to elucidate if there is a relationship between kinetic variables and ploidy status of human embryos or blastocyst developmental potential.

Methods:

For conducting this retrospective cohort study, the normal distribution of data was verified using Kolmogorov-Smirnov test with the Lilliefors’ amendment and the Shapiro-Wilk test. Kinetic variables were expressed as median and quartiles (Q1, Q2, Q3, Q4). Mann-Whitney U-test was used to compare the median values of parameters. Univariate and multiple logistic regression models were used to assess relationship between blastocyst developmental potential or ploidy status and kinetics. Several confounding factors were also assessed.

Results:

Blastocyst developmental potential was positively correlated with the t4-t3 interval (s2) (OR=1.417, 95% CI of 1.288–1.560). s2 median value was significantly different between high- and low-quality blastocysts (0.50 and 1.33 hours post-insemination, hpi, respectively; p=0.003). In addition, timing of pronuclear appearance (tPNa) (OR=1.287; 95% CI of 1.131–1.463) had a significant relationship with ploidy changes. The median value of tPNa was statistically different (p=0.03) between euploid and aneuploid blastocysts (Euploid blastocysts=8.9 hpi; aneuploid blastocysts=10.3 hpi).

Conclusion:

The present findings are in line with the study hypothesis that kinetic analysis may reveal associations between cleavage patterns and embryo development to the blastocyst stage and ploidy status.

Future of Health Services: The Role of Physicians in the Disruptive Era

This article aimed to address the role of physicians in future health in the disruptive era. Physicians in this disruptive era must increase their capability and knowledge to compensate for this development. Advances in technology increase the impact on health care and the significance of disruption. Disruptive innovation encompasses several fields, such as physics, digital, and biology. Big data as one of the most important parts in clinical aspects encompass high-throughput cellular and protein-binding assays toward chemoinformatic-driven databases. Health status can be modified by changing epigenetic factor, such as lifestyle and environment. As a result, they affect human genetics and provide the insight of pathophysiology of disease, clinical treatment, and early preventive action. Disruptive innovations in health-care align with the development of artificial intelligence, machine learning, robotics, Internet of things, digitalization, and genomics. New paradigm shifting in physician–patient relationships is relevant to consumer health informatics.

Embryo incubation by time-lapse systems versus conventional incubators in Chinese women with diminished ovarian reserve undergoing IVF/ICSI: a study protocol for a randomised controlled trial

INTRODUCTION

The time-lapse imaging system (TLS) is a newly developed non-invasive embryo assessment system. Compared with conventional incubators, a TLS provides stable culture conditions and consistent observations of embryo development, thereby potentially improving embryo quality and selection of the best quality embryo. Although TLSs have been routinely used in many in vitro fertilisation (IVF) centres globally, there is insufficient evidence to indicate that TLSs result in higher cumulative live birth rates over conventional incubators. The purpose of this study is to compare the cumulative live birth rates and safety including miscarriage in infertile patients with diminished ovarian reserve (DOR) from both TLSs and conventional incubators.

METHODS AND ANALYSIS

This study is a double-blind randomised controlled clinical trial (1:1 treatment ratio of TLSs vs conventional incubator). A total of 730 patients with DOR undergoing the first or second cycle of IVF or intracytoplasmic sperm injection (ICSI) will be enrolled and randomised into two parallel groups. Participants will undergo embryo culture in the TLSs (group A) or the conventional incubators (group B), respectively. Embryos are selected for transfer in both groups by the morphological characteristics. The embryo selection algorithm software is not used in the TLSs. The primary outcome is the cumulative live birth rate of the trial IVF/ICSI cycle within 12 months after randomisation. This study is powered to detect an absolute difference of 10% (35% vs 25%) at the significance level of 0.05% and 80% statistical power based on a two-sided test.

ETHICS AND DISSEMINATION

This trial has been approved by the Institutional Ethical Committee of Shanghai First Maternity and Infant Hospital (KS1958). All participants in the trial will provide written informed consent. The study will be conducted according to the principles outlined in the Declaration of Helsinki and its amendments. Results of this study will be disseminated in peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR1900027746).

Are morphokinetic parameters of embryo development associated with adverse perinatal outcomes following fresh blastocyst transfer?

RESEARCH QUESTION

Are obstetric and perinatal complications associated with morphokinetic parameters of embryo development?

DESIGN

This proof-of-concept pilot study included a retrospective analysis of embryo morphokinetic parameters of 85 live births following day 5 single blastocyst transfer. Kinetic variables included time interval (hours) from time of pronuclei fading (tPNf) to: time of 2 cells (tPNf-t2), 9 cells (tPNf-t9), morula (tPNf-tM), start of blastulation (tPNf-tSB), full blastocyst (tPNf-tB) and expanded blastocyst (tPNf-tEB). Multivariable logistic models were used to calculate the risk of perinatal complications after adjustment for confounders.

RESULTS

The mean interval of tPNf-tSB was significantly longer for newborns with congenital anomalies compared with healthy newborns (79.49 ± 5.78 versus 71.7 ± 6.3, respectively, P = 0.01) and for embryos of women who had gestational diabetes mellitus compared with normoglycemic women (76.56 ± 7.55 versus 71.5 ± 6.13, respectively, P = 0.015). The mean interval of tPNf-t9 was significantly longer for low-birthweight newborns compared with normal weight (49.25 ± 5.54 versus 45.47 ± 4.77, respectively, P = 0.01). Preterm delivery was associated with several longer intervals of cell divisions compared with delivery at term (tPNf-t5: 28.76 ± 3.13 versus 26.64 ± 2.40, respectively, P = 0.01; tPNf-t6: 30.10 ± 3.05 versus 27.68 ± 2.30, respectively, P < 0.001; tPNf-t7: 32.08 ± 4.11 versus 28.70 ± 2.67, respectively, P < 0.001; tPNf-t8: 34.75 ± 4.95 versus 30.70 ± 4.10, respectively, P < 0.001; tPNf-t9: 50.23 ± 5.87 versus 45.44 ± 4.67, respectively, P < 0.001). For each of the outcomes, the association remained significant after adjusting for confounders.

CONCLUSION

This study indicates that there may be a possible association between adverse perinatal outcomes and morphokinetic parameters. Larger studies are needed to establish this association.

Zona pellucida shear modulus, a possible novel non-invasive method to assist in embryo selection during in-vitro fertilization treatment

The present study investigated the association between oocyte zona pellucida shear modulus (ZPSM) and implantation rate (IR). Ninety-three oocytes collected from 38 in-vitro fertilization patients who underwent intracytoplasmic sperm injection were included in this case–control study. The ZP was modeled as an isotropic compressible hyperelastic material with parameter \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C_{10}$$\end{document}C10, which represents the ZPSM. Computational methodology was used to calculate the mechanical parameters that govern ZP deformation. Fifty-one developed embryos were transferred and divided into two groups—implanted and not implanted. Multivariate logistic regression analysis was performed to identify the association between ZPSM and IR while controlling for confounders. Maternal age and number of embryos per transfer were significantly associated with implantation. The IR of embryos characterized by \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C_{10}$$\end{document}C10 values in the range of 0.20–0.40 kPa was 66.75%, while outside this range it was 6.70%. This range was significantly associated with implantation (p < 0.001). Geometric properties were not associated with implantation. Multivariate logistic regression analysis that controlled for relevant confounders indicated that this range was independently associated with implantation (adjusted OR 38.03, 95% confidence interval 4.67–309.36, p = 0.001). The present study suggests that ZPSM may improve the classic embryo selection process with the aim of increasing IR.

Dynamics of cytoplasm and cleavage divisions correlates with preimplantation embryo development

In vitro fertilization has become increasingly popular as an infertility treatment. In order to improve efficiency of this procedure, there is a strong need for a refinement of existing embryo assessment methods and development of novel, robust and non-invasive selection protocols. Studies conducted on animal models can be extremely helpful here, as they allow for more extensive research on the potential biomarkers of embryo quality. In the present paper, we subjected mouse embryos to non-invasive time-lapse imaging and combined the Particle Image Velocimetry analysis of cytoplasmic dynamics in freshly fertilized oocytes with the morphokinetic analysis of recordings covering 5 days of preimplantation development. Our results indicate that parameters describing cytoplasmic dynamics and cleavage divisions independently correspond to mouse embryo's capacity to form a high-quality blastocyst. We also showed for the first time that these parameters are associated with the percentage of abnormal embryonic cells with fragmented nuclei and with embryo's ability to form primitive endoderm, one of the cell lineages differentiated during preimplantation development. Finally, we present a model that links selected cytoplasmic and morphokinetic parameters reflecting frequency of fertilization-induced Ca²⁺-oscillations and timing of 4-cell stage and compaction with viability of the embryo assessed as the total number of cells at the end of its preimplantation development. Our results indicate that a combined analysis of cytoplasmic dynamics and morphokinetics may facilitate the assessment of embryo's ability to form high-quality blastocysts.

Time-lapse imaging of cleavage divisions in embryo quality assessment

In vitro fertilization (IVF) is one of the most important procedures for treating infertility. As several embryos are usually produced in a single IVF cycle, it is crucial to select only the most viable ones for transfer to the patient. Morphokinetics, i.e. analysis of the dynamics of cleavage divisions and processes such as compaction and cavitation, has provided both biologists and clinicians with a new set of data regarding embryonic behaviour during preimplantation development and its association with embryo quality. In the current review, we focus on biological significance of morphokinetic parameters and show how they can be used to predict a reproductive outcome. We also explain the statistics behind the predictive algorithms and discuss the future perspectives of morphokinetics.

A prospective randomized comparison of early embryo cleavage kinetics between two media culture systems

OBJECTIVE

To investigate whether early embryo cleavage kinetics were affected by type of culture media.

METHODS

In this prospective sibling-split study, 620 oocytes from 37 patients were randomly allocated into two groups: Cook group and Vitrolife group. Oocytes/embryos in Cook group, would be cultured with Cook sequential culture medium, while oocytes/embryos in Vitrolife group, would be cultured with Vitrolife sequential culture medium. Time-lapse imaging technology was used to calculate exact timing of early embryo cleavage events which included time to 2PN breakdown, cleavage to 2-, 3-, 4-, 5- cell and the time duration in the 2-,3-cell stage. Then these timing of early embryo cleavage events were compared between Cook group and Vitrolife group. Moreover, fertilization rate, cleavage rate, high quality embryo rate, usable blastocyst rate, pregnancy rate and implantation rate of these two groups were also analyzed.

RESULTS

The results showed there were no differences in all timing of early embryo cleavage events between the two groups. In addition, the two groups were similar in fertilization rate (Cook 71.0% vs. Vitrolife 71.3%, P>0.05), cleavage rate (Cook 98.1% vs. Vitrolife 98.2%, P>0.05), high quality embryo rate (Cook 52.1% vs. Vitrolife 52.7%, P>0.05), usable blastocyst rate (Cook 29.7% vs. Vitrolife 28.0%, P>0.05), pregnancy rate (Cook 46.7% VS. Vitrolife 50.0%, P>0.05) and implantation rate (Cook 30.3% VS. Vitrolife 29.0%, P>0.05).

CONCLUSIONS

Morphokinetics used for embryo selection are not affected by the two different culture media.

Blastocyst development in single medium with or without renewal on day 3: a prospective cohort study on sibling donor oocytes in a time-lapse incubator

OBJECTIVE

To evaluate the efficiency of using a continuous (one-step) protocol with a single medium for the culture of human embryos in a time-lapse incubator (TLI).

DESIGN

Prospective cohort study on sibling donor oocytes.

SETTING

University-affiliated in vitro fertilization (IVF) center.

PATIENT(S)

Embryos from 59 patients.

INTERVENTION(S)

Culture in a TLI in a single medium with or without renewal of the medium on day-3.

MAIN OUTCOME MEASURE(S)

Embryo morphology and morphokinetic parameters, clinical pregnancy, take-home baby rate, and perinatal outcomes.

RESULT(S)

The blastocyst rates (68.3 vs. 66.8%) and the proportion of good-quality blastocysts (transferred plus frozen) obtained with the two-step (80.0%) protocol were statistically significantly similar to those obtained in the one-step protocol (72.2%). Similarly, morphokinetic events from early cleavage until late blastocyst stages were statistically significantly equivalent between both groups. No differences were found either in clinical pregnancy rates when comparing pure transfers performed with embryos selected from the two-step (75.0%), one-step (70.0%, respectively), and mixed (57.1%) groups. A total of 55 out of 91 embryos transferred implanted successfully (60.4%), resulting in a total of 37 newborns with a comparable birth weight mean among groups.

CONCLUSION(S)

Our findings support the idea that in a TLI with a controlled air purification system, human embryos can be successfully cultured continuously from day 0 onward in single medium with no need to renew it on day-3. This strategy does not affect embryo morphokinetics or development to term and offers more stable culture conditions for embryos as well as practical advantages and reduced costs for the IVF laboratory.

Morphokinetics of cloned mouse embryos treated with epigenetic drugs and blastocyst prediction

Time-lapse monitoring of somatic cell nuclear transfer (SCNT) embryos may help to predict developmental success and increase birth and embryonic stem cells (ESC) derivation rates. Here, the development of ICSI fertilized embryos and of SCNT embryos, non-treated or treated with either psammaplin A (PsA) or vitamin C (VitC), was monitored, and the ESC derivation rates from the resulting blastocysts were determined. Blastocyst rates were similar among PsA-treated and VitC-treated SCNT embryos and ICSI embryos, but lower for non-treated SCNT embryos. ESC derivation rates were higher in treated SCNT embryos than in non-treated or ICSI embryos. Time-lapse microscopy analysis showed that non-treated SCNT embryos had a delayed development from the second division until compaction, lower number of blastomeres at compaction and longer compaction and cavitation durations compared with ICSI ones. Treatment of SCNT embryos with PsA further increased this delay whereas treatment with VitC slightly reduced it, suggesting that both treatments act through different mechanisms, not necessarily related to their epigenetic effects. Despite these differences, the time of completion of the third division, alone or combined with the duration of compaction and/or the presence of fragmentation, had a strong predictive value for blastocyst formation in all groups. In contrast, we failed to predict ESC derivation success from embryo morphokinetics. Time-lapse technology allows the selection of SCNT embryos with higher developmental potential and could help to increase cloning outcomes. Nonetheless, further studies are needed to find reliable markers for full-term development and ESC derivation success.

Morphokinetic parameters of early embryo development via time lapse monitoring and their effect on embryo selection and ICSI outcomes: a prospective cohort study

PURPOSE

To compare the outcomes of embryos selected via time lapse monitoring (TLM) versus those selected with conventional methods of selection in subfertile women undergoing ICSI.

METHODS

The study population (239 women) was classified into two groups, based on the monitoring method used: Group 1 (TLM) and Group 2 (conventional monitoring). Groups were compared according to the clinical and ICSI cycle characteristics and reproductive outcomes, while transfers were performed at day 2 or 3. Subgroup analyses were performed, in women of both groups according to age and clinical parameters, and in embryos of Group 1 based on their cellular events.

RESULTS

There was a statistically significant difference between the two study groups with regard to the outcome parameters, favoring Group 1 and especially in women >40 years of age. No differences were found in subgroup analyses in participants of both groups, regarding the stimulation protocol used, number of the oocytes retrieved and type of subfertility, while in Group 1 the percentages of "in range" cellular events were higher in certain divisions in ages 35-40, non-smokers, and the GnRH-agonist group, and in embryos that resulted in pregnancy.

CONCLUSION

Morphokinetic parameters of early embryo development via TLM are related to the characteristics of subfertile patients and associated with ICSI outcomes.