Does the addition of time-lapse morphokinetics in the selection of embryos for transfer improve pregnancy rates? A randomized controlled trial

Effects of first and second division modes on euploidy acquisition in human embryo

The aim of this study was to non-invasively investigate euploid embryos using methods other than pre-implantation genetic testing for aneuploidy. The study focused on direct cleavage (DC) observed during early embryo development. We also investigated the relationship between the mode of early embryo division and embryo ploidy. Embryos were divided into the normal cleavage (NC) and DC groups, and the DC group was further subdivided into the DC-First (DC-F) and DC-Second (DC-S) groups, depending on whether DC was observed at the first or second cleavage, respectively. The acquisition rates of euploid embryos and embryos appropriate for transfer were compared between the groups. Our results revealed that the timing of the first division did not differ between blastocyst grades or in embryos with varying degrees of ploidy. Further, the timing of the first cleavage did not affect the acquisition rate of embryos appropriate for transfer and euploid embryo formation rate did not significantly differ between the DC and NC groups. We also noted that for embryos appropriate for transfer, euploidy acquisition rate did not differ significantly between the DC and NC groups. Further, the euploidy acquisition rate of embryos did not differ between the DC-F and DC-S groups. However, the acquisition rate of embryos appropriate for transfer, including those with low mosaicism, was significantly higher in the DC-S group than in the DC-F group. These findings indicated that the number of good-quality blastocysts formed was significantly higher in the NC group than in the DC group and the acquisition rate of embryos appropriate for transfer, including those with low mosaicism, was significantly higher in the DC-S group than in the DC-F group.

Clinical effectiveness and safety of time-lapse imaging systems for embryo incubation and selection in in-vitro fertilisation treatment (TILT): a multicentre, three-parallel-group, double-blind, randomised controlled trial

BACKGROUND

Time-lapse imaging systems for embryo incubation and selection might improve outcomes of in-vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) treatment due to undisturbed embryo culture conditions, improved embryo selection, or both. However, the benefit remains uncertain. We aimed to evaluate the effectiveness of time-lapse imaging systems providing undisturbed culture and embryo selection, and time-lapse imaging systems providing only undisturbed culture, and compared each with standard care without time-lapse imaging.

METHODS

We conducted a multicentre, three-parallel-group, double-blind, randomised controlled trial in participants undergoing IVF or ICSI at seven IVF centres in the UK and Hong Kong. Embryologists randomly assigned participants using a web-based system, stratified by clinic in a 1:1:1 ratio to the time-lapse imaging system for undisturbed culture and embryo selection (time-lapse imaging group), time-lapse imaging system for undisturbed culture alone (undisturbed culture group), and standard care without time-lapse imaging (control group). Women were required to be aged 18-42 years and men (ie, their partners) 18 years or older. Couples had to be receiving their first, second, or third IVF or ICSI treatment and could not participate if using donor gametes. Participants and trial staff were masked to group assignment, embryologists were not. The primary outcome was live birth. We performed analyses using the intention-to-treat principle and reported the main analysis in participants with primary outcome data available (full analysis set). The trial is registered on the International Trials Registry (ISRCTN17792989) and is now closed.

FINDINGS

1575 participants were randomly assigned to treatment groups (525 participants per group) between June 21, 2018, and Sept 30, 2022. The live birth rates were 33·7% (175/520) in the time-lapse imaging group, 36·6% (189/516) in the undisturbed culture group, and 33·0% (172/522) in the standard care group. The adjusted odds ratio was 1·04 (97·5% CI 0·73 to 1·47) for time-lapse imaging arm versus control and 1·20 (0·85 to 1·70) for undisturbed culture versus control. The risk reduction for the absolute difference was 0·7 percentage points (97·5% CI -5·85 to 7·25) between the time-lapse imaging and standard care groups and 3·6 percentage points (-3·02 to 10·22) between the undisturbed culture and standard care groups. 79 serious adverse events unrelated to the trial were reported (n=28 in time-lapse imaging, n=27 in undisturbed culture, and n=24 in standard care).

INTERPRETATION

In women undergoing IVF or ICSI treatment, the use of time-lapse imaging systems for embryo culture and selection does not significantly increase the odds of live birth compared with standard care without time-lapse imaging.

FUNDING

Barts Charity, Pharmasure Pharmaceuticals, Hong Kong OG Trust Fund, Hong Kong Health and Medical Research Fund, Hong Kong Matching Fund.

The synergy of morphokinetic parameters and sHLA-G in cleavage embryo enhancing implantation rates

Objective: This study aimed to assess the relationship between implantation and soluble HLA-G (sHLA-G) expression in cleavage embryo culture medium (ECM) in conjunction with early developmental kinetics determined by time-lapse imaging (TLI). Methods: A retrospective, single-center study was conducted involving 238 embryos from 165 patients who underwent Frozen-thawed embryo transfer (FET) using autologous oocytes, with either single or double embryo transfer. TLI morphokinetic parameters (t2, t3, t4, t5, t6, t7, t8, cc2, s2, cc3, s3) of embryos were analyzed, and sHLA-G levels in D3 ECM were measured using an enzyme-linked immunosorbent assay (ELISA). A hierarchical classification model was developed to categorize embryos into five groups (A, B, C, D, E). The correlation between sHLA-G levels, TLI classification of embryos, and embryo implantation was investigated to establish a non-invasive method for evaluating implantation potential. Multivariate logistic regression analysis was performed to identify potential influencing factors, and receiver operating characteristic (ROC) curves were used to evaluate the predictive value for implantation. Results: Multivariate unconditional logistic regression analysis indicated that TLI parameters t5 and s3 and sHLA-G level in ECM were independent risk factors affecting embryo implantation. The implantation rate decreased from TLI classification A to E. The proposed classification model effectively assessed the implantation potential of embryos. The implantation rate was higher in the sHLA-G positive group compared to the sHLA-G negative group (p < 0.001). The expression of sHLA-G in D3 ECM, combined with the TLI classification model, accurately evaluated the implantation potential of embryos with an AUC of 0.876. Conclusion: The integration of cleavage kinetics and embryonic sHLA-G expression could reliably identify embryos with a high likelihood of successful implantation.

METAPHOR: Metabolic evaluation through phasor-based hyperspectral imaging and organelle recognition for mouse blastocysts and oocytes

Only 30% of embryos from in vitro fertilized oocytes successfully implant and develop to term, leading to repeated transfer cycles. To reduce time-to-pregnancy and stress for patients, there is a need for a diagnostic tool to better select embryos and oocytes based on their physiology. The current standard employs brightfield imaging, which provides limited physiological information. Here, we introduce METAPHOR: Metabolic Evaluation through Phasor-based Hyperspectral Imaging and Organelle Recognition. This non-invasive, label-free imaging method combines two-photon illumination and AI to deliver the metabolic profile of embryos and oocytes based on intrinsic autofluorescence signals. We used it to classify i) mouse blastocysts cultured under standard conditions or with depletion of selected metabolites (glucose, pyruvate, lactate); and ii) oocytes from young and old mouse females, or in vitro-aged oocytes. The imaging process was safe for blastocysts and oocytes. The METAPHOR classification of control vs. metabolites-depleted embryos reached an area under the ROC curve (AUC) of 93.7%, compared to 51% achieved for human grading using brightfield imaging. The binary classification of young vs. old/in vitro-aged oocytes and their blastulation prediction using METAPHOR reached an AUC of 96.2% and 82.2%, respectively. Finally, organelle recognition and segmentation based on the flavin adenine dinucleotide signal revealed that quantification of mitochondria size and distribution can be used as a biomarker to classify oocytes and embryos. The performance and safety of the method highlight the accuracy of noninvasive metabolic imaging as a complementary approach to evaluate oocytes and embryos based on their physiology.

Formation of the first plane of division relative to the pronuclear axis predicts embryonic ploidy

RESEARCH QUESTION

Is there a relationship between the pronuclear axis and the first cleavage plane formation in human pronuclear-stage embryos, and what are the effects on ploidy and clinical pregnancy rates?

DESIGN

Transferred embryos were followed up until their prognoses. A total of 762 embryos formed two cells and reached the blastocyst stage after normal fertilization in a time-lapse incubator. Embryos were classified into three groups: group A: embryos in which the first plane of division was formed parallel to the axis of the pronucleus; group B: embryos in which cases of oblique formation were observed; and group C: embryos in which cases of perpendicular formation were observed.

RESULTS

The euploidy rate was significantly higher in groups A and B than those in group C (P < 0.01), whereas the aneuploidy rate was significantly higher in group C (P < 0.01) than in groups A and B. No differences were found between the three groups in frequency of positive HCG-based pregnancy tests, frequency of clinical pregnancies, miscarriage rates or delivery rates.

CONCLUSIONS

The formation pattern of the first plane of division relative to the pronuclear axis was a predictor of embryonic ploidy, with a reduced rate of euploidy and a high probability of aneuploidy observed when the first plane of division was perpendicular to the pronuclear axis.

The prospect of artificial intelligence to personalize assisted reproductive technology

Infertility affects 1-in-6 couples, with repeated intensive cycles of assisted reproductive technology (ART) required by many to achieve a desired live birth. In ART, typically, clinicians and laboratory staff consider patient characteristics, previous treatment responses, and ongoing monitoring to determine treatment decisions. However, the reproducibility, weighting, and interpretation of these characteristics are contentious, and highly operator-dependent, resulting in considerable reliance on clinical experience. Artificial intelligence (AI) is ideally suited to handle, process, and analyze large, dynamic, temporal datasets with multiple intermediary outcomes that are generated during an ART cycle. Here, we review how AI has demonstrated potential for optimization and personalization of key steps in a reproducible manner, including: drug selection and dosing, cycle monitoring, induction of oocyte maturation, and selection of the most competent gametes and embryos, to improve the overall efficacy and safety of ART.

Prediction of live birth - selection of embryos using morphokinetic parameters

BACKROUND

The goal of assisted reproduction is for a couple treated with IVF techniques to end the treatment by giving birth to a healthy baby. A neccessary presumption for success is the identification of the best embryo with high implantation and developmental potential. One option is to select an euploid embryo by invasive preimplantaion genetic testing for aneuploidy (PGT-A) or it is possible to select the best embryo by non-invasive time-lapse monitoring (TLM), specifically based on morphokinetic parameters and morphological markers that are able to identify an embryo with high developmental potential.

MATERIALS AND METHODS

The study involved a total of 1060 embryos (585 euploid and 475 aneuploid embryos after PGT-A) with good morphology from 329 patients in the period 01/2016-10/2021. All embryos were cultured in a time-lapse incubator, trophectoderm (TE) cells biopsies for PGT-A examination were performed on day 5 (D5) or day 6 (D6) of culture. During the study period, 225 frozen embryo transfers (FET) of one euploid embryo were performed. Based on the treatment outcome, the embryos were divided into 2 groups - euploid embryos, which led to the birth of a healthy child, and euploid embryos that did not show fetal heartbeat (FHB) after FET.

RESULTS

Based on the statistical analysis of the embryos without implantation and the embryos with live birth, it is clear that the morphokinetic parameters t5 (time of division into 5 cells) and tSB (time of start of blastulation) are significantly different.

CONCLUSION

The results suggest that of the morphokinetic parameters tSB and t5 are predictive indicators for selecting an embryo with high developmental potential and with a high probability of achieving the birth of a healthy child.

A comparison of morphokinetic models and morphological selection for prioritizing euploid embryos: a multicentre cohort study

STUDY QUESTION

Are morphokinetic models better at prioritizing a euploid embryo for transfer over morphological selection by an embryologist?

SUMMARY ANSWER

Morphokinetic algorithms lead to an improved prioritization of euploid embryos when compared to embryologist selection.

WHAT IS KNOWN ALREADY

PREFER (predicting euploidy for embryos in reproductive medicine) is a previously published morphokinetic model associated with live birth and miscarriage. The second model uses live birth as the target outcome (LB model).

STUDY DESIGN, SIZE, DURATION

Data for this cohort study were obtained from 1958 biopsied blastocysts at nine IVF clinics across the UK from January 2021 to December 2022.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The ability of the PREFER and LB models to prioritize a euploid embryo was compared against arbitrary selection and the prediction of four embryologists using the timelapse video, blinded to the morphokinetic time stamp. The comparisons were made using calculated percentages and normalized discounted cumulative gain (NDCG), whereby an NDCG score of 1 would equate to all euploid embryos being ranked first. In arbitrary selection, the ploidy status was randomly assigned within each cycle and the NDGC calculated, and this was then repeated 100 times and the mean obtained.

MAIN RESULTS AND THE ROLE OF CHANCE

Arbitrary embryo selection would rank a euploid embryo first 37% of the time, embryologist selection 39%, and the LB and PREFER ploidy morphokinetic models 46% and 47% of the time, respectively. The AUC for LB and PREFER model was 0.62 and 0.63, respectively. Morphological selection did not significantly improve the performance of both morphokinetic models when used in combination. There was a significant difference between the NDGC metric of the PREFER model versus embryologist selection at 0.96 and 0.87, respectively (t = 14.1, P < 0.001). Similarly, there was a significant difference between the LB model and embryologist selection with an NDGC metric of 0.95 and 0.87, respectively (t = 12.0, P < 0.001). All four embryologists ranked embryos similarly, with an intraclass coefficient of 0.91 (95% CI 0.82-0.95, P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

Aside from the retrospective study design, limitations include allowing the embryologist to watch the time lapse video, potentially providing more information than a truly static morphological assessment. Furthermore, the embryologists at the participating centres were familiar with the significant variables in time lapse, which could bias the results.

WIDER IMPLICATIONS OF THE FINDINGS

The present study shows that the use of morphokinetic models, namely PREFER and LB, translates into improved euploid embryo selection.

STUDY FUNDING/COMPETING INTEREST(S)

This study received no specific grant funding from any funding agency in the public, commercial or not-for-profit sectors. Dr Alison Campbell is minor share holder of Care Fertility. All other authors have no conflicts of interest to declare. Time lapse is a technology for which patients are charged extra at participating centres.

TRIAL REGISTRATION NUMBER

N/A.

Developmental perturbation in human embryos: Clinical and biological significance learned from time-lapse images

Background

Time-lapse technology (TLT) has gained widespread adoption worldwide. In addition to facilitating the undisturbed culture of embryos, TLT offers the unique capability of continuously monitoring embryos to detect spatiotemporal changes. Although these observed phenomena play a role in optimal embryo selection/deselection, the clinical advantages of introducing TLT remain unclear. However, manual annotation of embryo perturbation could facilitate a comprehensive assessment of developmental competence. This process requires a thorough understanding of embryo observation and the biological significance associated with developmental dogma and variation. This review elucidates the typical behavior and variation of each phenomenon, exploring their clinical significance and research perspectives.

Methods

The MEDLINE database was searched using PubMed for peer-reviewed English-language original articles concerning human embryo development.

Main findings

TLT allows the observation of consecutive changes in embryo morphology, serving as potential biomarkers for embryo assessment. In assisted reproductive technology laboratories, several phenomena have not revealed their mechanism, posing difficulties such as fertilization deficiency and morula arrest.

Conclusion

A profound understanding of the biological mechanisms and significance of each phenomenon is crucial. Further collaborative efforts between the clinical and molecular fields following translational studies are required to advance embryonic outcomes and assessment.

Considerations for future modification of The Association for the Study of Reproductive Biology embryo grading system incorporating time-lapse observations

The Association for the Study of Reproductive Biology (ASEBIR) Interest Group in Embryology (in Spanish 'Grupo de Interés de Embriología') reviewed key morphokinetic parameters to assess the contribution of time-lapse technology (TLT) to the ASEBIR grading system. Embryo grading based on morphological characteristics is the most widely used method in human assisted reproduction laboratories. The introduction and implementation of TLT has provided a large amount of information that can be used as a complementary tool for morphological embryo evaluation and selection. As part of IVF treatments, embryologists grade embryos to decide which embryos to transfer or freeze. At the present, the embryo grading system developed by ASEBIR does not consider dynamic events observed through TLT. Laboratories that are using TLT consider those parameters as complementary data for embryo selection. The aim of this review was to evaluate review time-specific morphological changes during embryo development that are not included in the ASEBIR scoring system, and to consider them as candidates to add to the scoring system.

No major differences in perinatal and maternal outcomes between uninterrupted embryo culture in time-lapse system and conventional embryo culture

STUDY QUESTION

Is embryo culture in a closed time-lapse system associated with any differences in perinatal and maternal outcomes in comparison to conventional culture and spontaneous conception?

SUMMARY ANSWER

There were no significant differences between time-lapse and conventional embryo culture in preterm birth (PTB, <37 weeks), low birth weight (LBW, >2500 g) and hypertensive disorders of pregnancy for singleton deliveries, the primary outcomes of this study.

WHAT IS KNOWN ALREADY

Evidence from prospective trials evaluating the safety of time-lapse incubation for clinical use show similar embryo development rates, implantation rates, and ongoing pregnancy and live birth rates when compared to conventional incubation. Few studies have investigated if uninterrupted culture can alter risks of adverse perinatal outcomes presently associated with IVF when compared to conventional culture and spontaneous conceptions.

STUDY DESIGN, SIZE, DURATION

This study is a Swedish population-based retrospective registry study, including 7379 singleton deliveries after fresh embryo transfer between 2013 and 2018 from selected IVF clinics. Perinatal outcomes of singletons born from time-lapse-cultured embryos were compared to singletons from embryos cultured in conventional incubators and 71 300 singletons from spontaneous conceptions. Main perinatal outcomes included PTB and LBW. Main maternal outcomes included hypertensive disorders of pregnancy (pregnancy hypertension and preeclampsia).

PARTICIPANTS/MATERIALS, SETTING, METHODS

From nine IVF clinics, 2683 singletons born after fresh embryo transfer in a time-lapse system were compared to 4696 singletons born after culture in a conventional incubator and 71 300 singletons born after spontaneous conception matched for year of birth, parity, and maternal age. Patient and treatment characteristics from IVF deliveries were cross-linked with the Swedish Medical Birth Register, Register of Birth Defects, National Patient Register and Statistics Sweden. Children born after sperm and oocyte donation cycles and after Preimplantation Genetic testing cycles were excluded. Odds ratio (OR) and adjusted OR were calculated, adjusting for relevant confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

In the adjusted analyses, no significant differences were found for risk of PTB (adjusted OR 1.11, 95% CI 0.87-1.41) and LBW (adjusted OR 0.86, 95% CI 0.66-1.14) or hypertensive disorders of pregnancy; preeclampsia and hypertension (adjusted OR 0.99, 95% CI 0.67-1.45 and adjusted OR 0.98, 95% CI 0.62-1.53, respectively) between time-lapse and conventional incubation systems. A significantly increased risk of PTB (adjusted OR 1.31, 95% CI 1.08-1.60) and LBW (adjusted OR 1.36, 95% CI 1.08-1.72) was found for singletons born after time-lapse incubation compared to singletons born after spontaneous conceptions. In addition, a lower risk for pregnancy hypertension (adjusted OR 0.72 95% CI 0.53-0.99) but no significant difference for preeclampsia (adjusted OR 0.87, 95% CI 0.68-1.12) was found compared to spontaneous conceptions. Subgroup analyses showed that some risks were related to the day of embryo transfer, with more adverse outcomes after blastocyst transfer in comparison to cleavage stage transfer.

LIMITATIONS, REASONS FOR CAUTION

This study is retrospective in design and different clinical strategies may have been used to select specific patient groups for time-lapse versus conventional incubation. The number of patients is limited and larger datasets are required to obtain more precise estimates and adjust for possible effect of additional embryo culture variables.

WIDER IMPLICATIONS OF THE FINDINGS

Embryo culture in time-lapse systems is not associated with major differences in perinatal and maternal outcomes, compared to conventional embryo culture, suggesting that this technology is an acceptable alternative for embryo incubation.

STUDY FUNDING/COMPETING INTEREST(S)

The study was financed by a research grant from Gedeon Richter. There are no conflicts of interest for all authors to declare.

TRIAL REGISTRATION NUMBER

N/A.

The effect of embryo selection using time-lapse monitoring on IVF/ICSI outcomes: A systematic review and meta-analysis

AIM

To explore the effect of embryo selection using the time-lapse monitoring (TLM) system compared with conventional morphological selection (CMS) on in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes.

METHODS

We searched PubMed, Ovid-Embase, and The Cochrane Library for the following studies: At Comparison 1, embryo selection using TLM images in a TLM incubator based on morphology versus embryo selection using CMS in a conventional incubator based on morphology; at Comparison 2, embryo selection using TLM based on morphokinetics versus embryo selection using CMS based on morphology. The primary outcomes were the live birth rate (LBR), ongoing pregnancy rate (OPR), clinical pregnancy rate (CPR), and implantation rate (IR), and the secondary outcome was the miscarriage rate (MR).

RESULTS

A total of 14 randomized control trials (RCTs) were included. Both based on morphology, TLM incubators increased the IR (risk ratio [RR]: 1.10; 95% confidence interval [CI]: 1.01, 1.18; I2  = 0%, moderate-quality evidence) compared to conventional incubators. Low- to moderate-quality evidence suggests that TLM incubators did not improve LBR, OPR, CPR, and MR compared to conventional incubators. In addition, low- to moderate-quality evidence indicates that embryo selection using TLM based on morphokinetics did not improve LBR, OPR, CPR, IR, or MR compared to CMS based on morphology.

CONCLUSIONS

Low- to moderate-quality evidence suggests that neither TLM incubators nor embryo selection using TLM based on morphokinetics improved clinical outcomes (LBR, OPR, CPR, and MR) compared with CMS based on morphology. TLM is still an investigational procedure for IVF/ICSI practice.

Association between a morphokinetic ploidy prediction model risk score and miscarriage and live birth: a multicentre cohort study

OBJECTIVE

To determine whether the aneuploidy risk score from a morphokinetic ploidy prediction model, Predicting Euploidy for Embryos in Reproductive Medicine (PREFER), is associated with miscarriage and live birth outcomes.

DESIGN

Multicentre cohort study.

SETTING

Nine in vitro fertilization clinics in the United Kingdom.

PATIENTS

Data were obtained from the treatment of patients from 2016-2019. A total of 3587 fresh single embryo transfers were included; preimplantation genetic testing for aneuploidy) cycles were excluded.

INTERVENTION

PREFER is a model developed using 8,147 biopsied blastocyst specimens to predict ploidy status using morphokinetic and clinical biodata. A second model using only morphokinetic (MK) predictors was developed, P PREFER-MK. The models will categorize embryos into the following three risk score categories for aneuploidy: "high risk," "medium risk," and "low risk."

MAIN OUTCOME MEASURES

The primary outcomes are miscarriage and live birth. Secondary outcomes include biochemical clinical pregnancy per single embryo transfer.

RESULTS

When applying PREFER, the miscarriage rates were 12%, 14%, and 22% in the "low risk," "moderate risk," and "high risk" categories, respectively. Those embryos deemed "high risk" had a significantly higher egg provider age compared with "low risk," and there was little variation in risk categories in patients of the same age. The trend in miscarriage rate was not seen when using PREFER-MK; however, there was an association with live birth, increasing from 38%-49% and 50% in the "high risk," "moderate risk," and "low risk" groups, respectively. An adjusted logistic regression analysis demonstrated that PREFER-MK was not associated with miscarriage when comparing "high risk" to "moderate risk" embryos (odds ratio [OR], 0.87; 95% confidence interval [CI], 0.63-1.63) or "high risk" to "low risk" embryos (OR, 1.07; 95% CI, 0.79-1.46). An embryo deemed "low risk" by PREFER-MK was significantly more likely to result in a live birth than those embryos graded "high risk" (OR, 1.95; 95% CI, 1.65-2.25).

CONCLUSION

The PREFER model's risk scores were significantly associated with live births and miscarriages. Importantly, this study also found that this model applied too much weight to clinical factors, such that it could no longer rank a patient's embryos effectively. Therefore, a model including only MKs would be preferred; this was similarly associated with live birth but not miscarriage.

An artificial intelligence algorithm for automated blastocyst morphometric parameters demonstrates a positive association with implantation potential

Blastocyst selection is primarily based on morphological scoring systems and morphokinetic data. These methods involve subjective grading and time-consuming techniques. Artificial intelligence allows for objective and quick blastocyst selection. In this study, 608 blastocysts were selected for transfer using morphokinetics and Gardner criteria. Retrospectively, morphometric parameters of blastocyst size, inner cell mass (ICM) size, ICM-to-blastocyst size ratio, and ICM shape were automatically measured by a semantic segmentation neural network model. The model was trained on 1506 videos with 102 videos for validation with no overlap between the ICM and trophectoderm models. Univariable logistic analysis found blastocyst size and ICM-to-blastocyst size ratio to be significantly associated with implantation potential. Multivariable regression analysis, adjusted for woman age, found blastocyst size to be significantly associated with implantation potential. The odds of implantation increased by 1.74 for embryos with a blastocyst size greater than the mean (147 ± 19.1 μm). The performance of the algorithm was represented by an area under the curve of 0.70 (p < 0.01). In conclusion, this study supports the association of a large blastocyst size with higher implantation potential and suggests that automatically measured blastocyst morphometrics can be used as a precise, consistent, and time-saving tool for improving blastocyst selection.

External validation of a model for selecting day 3 embryos for transfer based upon deep learning and time-lapse imaging

RESEARCH QUESTION

Could objective embryo assessment using iDAScore Version 2.0 perform as well as conventional morphological assessment?

DESIGN

A retrospective cohort study of fresh day 3 embryo transfer cycles was conducted at a large reproductive medicine centre. In total, 7786 embryos from 4328 cycles with known implantation data were cultured in a time-lapse incubator and included in the study. Fetal heartbeat (FHB) rate was analysed retrospectively using iDAScore Version 2.0 and conventional morphological assessment associated with the transferred embryos. The pregnancy-prediction performance of the two assessment methods was compared using area under the curve (AUC) values for predicting FHB.

RESULTS

AUC values were significantly higher for iDAScore compared with morphological assessment for all cycles (0.62 versus 0.60; P = 0.005), single-embryo transfer cycles (0.63 versus 0.60; P = 0.043) and double-embryo transfer cycles (0.61 versus 0.59; P = 0.012). For the age subgroups, AUC values were significantly higher for iDAScore compared with morphological assessment in the <35 years subgroup (0.62 versus 0.60; P = 0.009); however, no significant difference was found in the ≥35 years subgroup. In terms of the number of blastomeres, AUC values were significantly higher for iDAScore compared with morphological assessment for both the <8c subgroup (0.67 versus 0.56; P < 0.001) and the ≥8c subgroup (0.58 versus 0.55; P = 0.012).

CONCLUSIONS

iDAScore Version 2.0 performed as well as, or better than, conventional morphological assessment in fresh day 3 embryo transfer cycles. iDAScore Version 2.0 may therefore constitute a promising tool for selecting embryos with the highest likelihood of implantation.

Morphokinetic parameters of mouse oocyte meiotic maturation and cumulus expansion are not affected by reproductive age or ploidy status

INTRODUCTION

Morphokinetic analysis using a closed time-lapse monitoring system (EmbryoScope + ™) provides quantitative metrics of meiotic progression and cumulus expansion. The goal of this study was to use a physiologic aging mouse model, in which egg aneuploidy levels increase, to determine whether there are age-dependent differences in morphokinetic parameters of oocyte maturation.

METHODS

Denuded oocytes and intact cumulus-oocyte complexes (COCs) were isolated from reproductively young and old mice and in vitro matured in the EmbryoScope + ™. Morphokinetic parameters of meiotic progression and cumulus expansion were evaluated, compared between reproductively young and old mice, and correlated with egg ploidy status.

RESULTS

Oocytes from reproductively old mice were smaller than young counterparts in terms of GV area (446.42 ± 4.15 vs. 416.79 ± 5.24 µm2, p < 0.0001) and oocyte area (4195.71 ± 33.10 vs. 4081.62 ± 41.04 µm2, p < 0.05). In addition, the aneuploidy incidence was higher in eggs with advanced reproductive age (24-27% vs. 8-9%, p < 0.05). There were no differences in the morphokinetic parameters of oocyte maturation between oocytes from reproductively young and old mice with respect to time to germinal vesicle breakdown (GVBD) (1.03 ± 0.03 vs. 1.01 ± 0.04 h), polar body extrusion (PBE) (8.56 ± 0.11 vs. 8.52 ± 0.15 h), duration of meiosis I (7.58 ± 0.10 vs. 7.48 ± 0.11 h), and kinetics of cumulus expansion (0.093 ± 0.002 vs. 0.089 ± 0.003 µm/min). All morphokinetic parameters of oocyte maturation were similar between euploid and aneuploid eggs irrespective of age.

CONCLUSION

There is no association between age or ploidy and the morphokinetics of mouse oocyte in vitro maturation (IVM). Future studies are needed to evaluate whether there is an association between morphokinetic dynamics of mouse IVM and embryo developmental competence.

Clinical outcomes of uninterrupted embryo culture with or without time-lapse-based embryo selection versus interrupted standard culture (SelecTIMO): a three-armed, multicentre, double-blind, randomised controlled trial

BACKGROUND

Time-lapse monitoring is increasingly used in fertility laboratories to culture and select embryos for transfer. This method is offered to couples with the promise of improving pregnancy chances, even though there is currently insufficient evidence for superior clinical results. We aimed to evaluate whether a potential improvement by time-lapse monitoring is caused by the time-lapse-based embryo selection method itself or the uninterrupted culture environment that is part of the system.

METHODS

In this three-armed, multicentre, double-blind, randomised controlled trial, couples undergoing in-vitro fertilisation or intracytoplasmic sperm injection were recruited from 15 fertility clinics in the Netherlands and randomly assigned using a web-based, computerised randomisation service to one of three groups. Couples and physicians were masked to treatment group, but embryologists and laboratory technicians could not be. The time-lapse early embryo viability assessment (EEVA; TLE) group received embryo selection based on the EEVA time-lapse selection method and uninterrupted culture. The time-lapse routine (TLR) group received routine embryo selection and uninterrupted culture. The control group received routine embryo selection and interrupted culture. The co-primary endpoints were the cumulative ongoing pregnancy rate within 12 months in all women and the ongoing pregnancy rate after fresh single embryo transfer in a good prognosis population. Analysis was by intention to treat. This trial is registered on the ICTRP Search Portal, NTR5423, and is closed to new participants.

FINDINGS

1731 couples were randomly assigned between June 15, 2017, and March 31, 2020 (577 to the TLE group, 579 to the TLR group, and 575 to the control group). The 12-month cumulative ongoing pregnancy rate did not differ significantly between the three groups: 50·8% (293 of 577) in the TLE group, 50·9% (295 of 579) in the TLR group, and 49·4% (284 of 575) in the control group (p=0·85). The ongoing pregnancy rates after fresh single embryo transfer in a good prognosis population were 38·2% (125 of 327) in the TLE group, 36·8% (119 of 323) in the TLR group, and 37·8% (123 of 325) in the control group (p=0·90). Ten serious adverse events were reported (five TLE, four TLR, and one in the control group), which were not related to study procedures.

INTERPRETATION

Neither time-lapse-based embryo selection using the EEVA test nor uninterrupted culture conditions in a time-lapse incubator improved clinical outcomes compared with routine methods. Widespread application of time-lapse monitoring for fertility treatments with the promise of improved results should be questioned.

FUNDING

Health Care Efficiency Research programme from Netherlands Organisation for Health Research and Development and Merck.

Non-invasive evaluation of embryos using mid-infrared attenuated total reflection spectrometry of incubation medium: a preliminary study

RESEARCH QUESTION

Can mid-infrared attenuated total reflection (MIR ATR) spectroscopy combined with machine learning methods be used as an additional tool to predict embryo quality and IVF treatment outcomes?

DESIGN

Spent culture media was collected and analysed. MIR ATR absorbance spectra were measured using an ALPHA II spectrometer equipped with an attenuated total reflection (ATR) spectrometry accessory. Patient and treatment data and results were collected and analysed in combination with machine learning techniques to identify possible correlations. The main outcome measures were to define the characteristics of absorbance spectra of spent culture media and to distinguish the difference in absorbance between top- and low-quality embryos, day 3 and day 5 embryos and implanting embryos versus non-implanting embryos.

RESULTS

Spent culture media of 227 embryos was collected and analysed. Absorbance peaks in the culture media were different between day 3 and day 5 embryos. Moreover, significant differences in P-values, spanning from 0.014 to 0.044 in absorbance peaks for day 3 embryos and 0.024 up to 0.04 for day 5 embryos, were seen between implanting and non-implanting embryos. Machine learning techniques offered a pregnancy prediction value of 84.6% for day 3 embryos.

CONCLUSIONS

MIR ATR may offer an additional parameter for better selection of embryos based on the spectrometric absorbance and secretions of metabolites in the culture media.

Are Early Embryo Cleavage Kinetics Affected by Energy Substrates in Different Culture Media?

OBJECTIVE

This study aimed to investigate the influence of different culture media on early embryonic cleavage kinetics using time-lapse analysis and to determine the possible relationships between energy substrates in culture media and the cleavage kinetics.

METHODS

A total of 10 021 embryos from 1310 couples were cultured in time-lapse incubators. Embryos cultured in Vitrolife media were allocated to group I, and those in COOK media to group II. Embryo cleavage time points up to the 8-cell stage (t2-t8) were observed after pronuclei fading.

RESULTS

The baseline demographic features, in vitro fertilization indications, ovarian stimulation protocol, oocyte-cumulus complexes, fertilization rate, together with pregnancy and perinatal outcomes were similar (P>0.05) between groups I and II. According to the time-lapse analysis, all embryos in group I showed significantly faster cleavage speed than those in group II (P<0.05). Furthermore, there was better synchrony in division (s3) and a longer length of the third cell cycle duration (cc3) in group II. Interestingly, implanted embryos in group II showed faster cleavage speed than those in group I, especially at t4 and t7. The glucose contents and multiple major amino acids were similar between the two groups. Lactic and pyruvic acid contents were generally higher in group I than those in group II.

CONCLUSION

Because different commercial culture media may influence cleavage kinetics of embryos, it is essential for embryologists to take culture media into consideration in selecting a potential embryo when using a time-lapse system before implantation.

Quantitative approaches in clinical reproductive endocrinology

Understanding the human hypothalamic-pituitary-gonadal (HPG) axis presents a major challenge for medical science. Dysregulation of the HPG axis is linked to infertility and a thorough understanding of its dynamic behaviour is necessary to both aid diagnosis and to identify the most appropriate hormonal interventions. Here, we review how quantitative models are being used in the context of clinical reproductive endocrinology to: 1. analyse the secretory patterns of reproductive hormones; 2. evaluate the effect of drugs in fertility treatment; 3. aid in the personalization of assisted reproductive technology (ART). In this review, we demonstrate that quantitative models are indispensable tools enabling us to describe the complex dynamic behaviour of the reproductive axis, refine the treatment of fertility disorders, and predict clinical intervention outcomes.

Non-invasive evaluation of embryo quality for the selection of transferable embryos in human in vitro fertilization-embryo transfer

The ultimate goal of human assisted reproductive technology is to achieve a healthy pregnancy and birth, ideally from the selection and transfer of a single competent embryo. Recently, techniques for efficiently evaluating the state and quality of preimplantation embryos using time-lapse imaging systems have been applied. Artificial intelligence programs based on deep learning technology and big data analysis of time-lapse monitoring system during in vitro culture of preimplantation embryos have also been rapidly developed. In addition, several molecular markers of the secretome have been successfully analyzed in spent embryo culture media, which could easily be obtained during in vitro embryo culture. It is also possible to analyze small amounts of cell-free nucleic acids, mitochondrial nucleic acids, miRNA, and long non-coding RNA derived from embryos using real-time polymerase chain reaction (PCR) or digital PCR, as well as next-generation sequencing. Various efforts are being made to use non-invasive evaluation of embryo quality (NiEEQ) to select the embryo with the best developmental competence. However, each NiEEQ method has some limitations that should be evaluated case by case. Therefore, an integrated analysis strategy fusing several NiEEQ methods should be urgently developed and confirmed by proper clinical trials.

Embryo Morphokinetic Activity Evident in Short Videos of In Vitro Bovine Embryos

Embryo transfer (ET) and in vitro fertilization (IVF) are increasing in use by dairy producers as a means to breed their animals as these assisted reproductive techniques can optimize the genetics of the dairy breed or enable “beef on dairy” programs to increase the profitability of the dairy. Due to the advantages of ET and IVF, it is anticipated that their use will continue to increase despite the status of underwhelmingly low pregnancy outcomes. Pregnancy rates of bovine ET/IVF remain below 56%, with many dairy producers implementing beef on dairy programs reporting pregnancy to be lower than 23%. The inability to objectively evaluate embryo health prior to transfer into a recipient is a contributing factor to this problem as 20% of transferred embryos are inviable at the time of transfer and have little chance of establishing a pregnancy. The objective of this research was to evaluate bovine embryo real-time morphokinetic activity based on 30 s video recordings of day 7.5 morulas and correlate morphokinetic activity to developmental outcomes. Eighty-eight embryos were recorded in standard embryo culture conditions with an SMZ-1000 Stereo zoom microscope and TE-300 Nikon inverted microscope. The difference in the embryo’s morphokinetic activity was measured frame-by-frame and correlated to embryo hatching outcomes. It was found that embryos with lower morphokinetic activity demonstrated higher hatching rates and developmental outcomes, suggesting measurement of embryo morphokinetic activity is a noninvasive and non-subjective method to evaluate embryo competency prior to transfer and can be used to improve the reproductive efficiency and profitability of IVF/ET of dairy cattle.

Quantitative morphokinetic parameters identify novel dynamics of oocyte meiotic maturation and cumulus expansion†

Meiotic maturation and cumulus expansion are essential for the generation of a developmentally competent gamete, and both processes can be recapitulated in vitro. We used a closed time-lapse incubator (EmbryoScope+™) to establish morphokinetic parameters of meiotic progression and cumulus expansion in mice and correlated these outcomes with egg ploidy. The average time to germinal vesicle breakdown (GVBD), time to first polar body extrusion (PBE), and duration of meiosis I were 0.91 ± 0.01, 8.82 ± 0.06, and 7.93 ± 0.06 h, respectively. The overall rate of cumulus layer expansion was 0.091 ± 0.002 μm/min, and the velocity of expansion peaked during the first 8 h of in vitro maturation (IVM) and then slowed. IVM of oocytes exposed to Nocodazole, a microtubule disrupting agent, and cumulus oocyte complexes (COCs) to 4-methylumbelliferone, a hyaluronan synthesis inhibitor, resulted in a dose-dependent perturbation of morphokinetics, thereby validating the system. The incidence of euploidy following IVM was >90% for both denuded oocytes and intact COCs. No differences were observed between euploid and aneuploid eggs with respect to time to GVBD (0.90 ± 0.22 vs. 0.97 ± 0.19 h), time to PBE (8.89 ± 0.98 vs. 9.10 ± 1.42 h), duration of meiosis I (8.01 ± 0.91 vs. 8.13 ± 1.38 h), and overall rate and kinetics of cumulus expansion (0.089 ± 0.02 vs 0.088 ± 0.03 μm/min) (P > 0.05). These morphokinetic parameters provide novel quantitative and non-invasive metrics for the evaluation of meiotic maturation and cumulus expansion and will enable screening compounds that modulate these processes.

A propensity score-based, comparative study assessing humid and dry time-lapse incubation, with single-step medium, on embryo development and clinical outcomes

STUDY QUESTION

Does culture in a high relative humidity atmosphere improve clinical outcomes when using a time-lapse integrated incubator and single-step culture medium?

SUMMARY ANSWER

Using an integrated time-lapse system and single-step culture medium, culture in a high relative humidity atmosphere increases the likelihood of embryos, especially those subjected to preimplantation genetic testing for aneuploidies, to achieve a pregnancy compared to those cultured in dry conditions.

WHAT IS KNOWN ALREADY

The use of a humid atmosphere inside incubators can reduce changes in culture media osmolality, which has been reported to have a significant effect on embryo quality and morphokinetics. Studies assessing the effect of humid culture (HC) in clinical outcomes are, however, scarce and inconclusive, mostly due to a high variability in culture conditions and reduced sample size.

STUDY DESIGN, SIZE, DURATION

Retrospective cohort study performed over 1627 ICSI cycles performed during 3 consecutive years in which embryo cohorts were cultured in a time-lapse incubator with three dry and three humidified chambers, and using single-step culture medium. Clinical outcomes were compared between treatments in which embryo cohorts were cultured in either humid (n = 833) or dry (n = 794) conditions.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study includes autologous treatments, with (N = 492) and without (N = 372) preimplantation genetic testing for aneuploidies (PGT-A) and ovum donation treatments (N = 763), performed in three university-affiliated private IVF centres. Stimulation, oocyte pickup and fertilization were performed according to the standard procedures of the clinic. All embryo cohorts were cultured in the same model of time-lapse incubator, distributed to either a dry or humidified chamber, while the rest of the culture variables remained equal. The population was weighted by the inverse probability of treatment to control for all measured confounders. The association between HC and the main outcome was assessed by logistic regression over the weighted population. The E-value was reported as a way of considering for unmeasured confounders. Differences in embryo development and other secondary outcomes between the study groups were assessed by Pearson Chi-squared test, ANOVA test and Kaplan-Meier survival analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

An univariable logistic regression analysis, weighted by the inverse probability of treatment, determined that embryos cultured in humid conditions are more likely to achieve a clinical pregnancy than those cultured in dry conditions (odds ratio (OR) = 1.236 (95% CI 1.009-1.515), P = 0.041, E = 1.460). Through stratification, it was determined that said effect is dependent on the type of treatment: no improvement in clinical pregnancy was present in ovum donation or autologous treatments, but a statistically significant positive effect was present in treatments with preimplantation genetic testing (OR = 1.699 (95% CI 1.084-2.663), P = 0.021, E = 1.930). Said increase does not relate with an improvement in later outcomes. Differences were also found in variables related to embryo developmental morphokinetics.

LIMITATIONS, REASONS FOR CAUTION

The retrospective nature of the study makes it susceptible to some bias linked to the characteristics of the treatments. To lessen the effect of possible biases, cases were weighted by the inverse probability of treatment prior to the evaluation of the outcome, as means to assess for measured confounders. In addition, the E-value of the weighted OR was calculated as a sensitivity analysis for unmeasured confounders. A randomized prospective study could be performed for further assessing the effect of humid conditions in clinical outcome.

WIDER IMPLICATIONS OF THE FINDINGS

These results support that embryo culture under conditions of high relative humidity contributes to optimize clinical results in undisturbed culture in a time-lapse incubator with single-step medium. To our knowledge, this is the largest study on the matter and the first performing a propensity score-based analysis.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the ''Centro para el Desarrollo Tecnologico Industrial'' from the Spanish Ministry of Science, Innovation, and Universities (CDTI-20170310) and Generalitat Valenciana and European Social Fund (ACIF/2019/264). None of the authors have any competing interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Zygote Diameter and Total Cytoplasmic Volume as Useful Predictive Tools of Blastocyst Quality

Introduction According to the Embryo Protection Act, the selection of embryos with the greatest potential for successful implantation in Germany must be performed in the pronucleus stage. The main aim of this study was to identify morphokinetic parameters that could serve as noninvasive biomarkers of blastocyst quality in countries with restrictive reproductive medicine laws. Materials and Methods The sample comprised 191 embryos from 40 patients undergoing antagonist cycles for intracytoplasmic sperm injection. Blastocysts were cultured in an EmbryoScope chamber and video records were validated to determine the post-injection timing of various developmental stages, cleavage stages, and blastocyst formation. The Gardner and Schoolcraft scoring system was used to characterize blastocyst quality. Results Morphokinetic data showed that the zygote diameter and total cytoplasmic volume were significantly different between good and poor blastocysts quality groups, where zygotes, which formed better blastocyst quality, had smaller diameter and smaller total cytoplasmic volume. Zygotes with more rapid pronuclear disappearance developed in better-quality blastocysts. Differences between good- and poor-quality blastocysts were also observed for late-stage parameters and for the spatial arrangement of blastomere where tetrahedral embryos more frequently forming good-quality blastocyst compare to the non-tetrahedral. Conclusions The study findings could be used to enhance embryo selection, especially in countries with strict Embryo Law Regulations. Further studies, including those in which the implantation potential and pregnancy rate are considered, are warranted to confirm these preliminary results.

The Impact of Culture Medium on Morphokinetics of Cleavage Stage Embryos: An Observational Study

To study the impact of culture media on preimplantation morphokinetics used for predicting clinical outcomes. All IVF and ICSI cycles performed between 2012 and 2017 with time-lapse information available were included. In November 2014, culture medium was changed from Vitrolife G-1 PLUS to SAGE 1-Step. Each embryo was retrospectively assigned a morphokinetic-based KIDScore for prediction of implantation. Clinical outcomes were retrieved from medical records. Linear mixed models were used to study differences in morphokinetic parameters, a proportional odds model for KIDScore ranking and logistic regression for differences in clinical outcomes. All analyses were adjusted for patient and treatment characteristics. In 253 (63.1%) cycles, embryos (n = 671) were cultured in Vitrolife, and in 148 (36.9%) cycles, embryos (n = 517) were cultured in SAGE. All cleavage divisions occurred earlier for SAGE embryos than for Vitrolife embryos (2-cell: -2.28 (95%CI: -3.66, -0.89), 3-cell: -2.34 (95%CI: -4.00, -0.64), 4-cell: -2.41 (95%CI: -4.11, -0.71), 5-cell: -2.54 (95%CI: -4.90, -0.18), 6-cell: -3.58 (95%CI: -6.08, -1.08), 7-cell: -5.62 (95%CI: -8.80, -2.45) and 8-cell: -5.32 (95%CI: -9.21, -1.42) hours, respectively). Significantly more embryos cultured in SAGE classified for the highest KIDScore compared to embryos cultured in Vitrolife (p < 0.001). No differences were observed in clinical outcomes. Our results demonstrate an impact of culture medium on preimplantation embryo developmental kinetics, which affects classification within the KIDScore algorithm, while pregnancy outcomes were comparable between the groups. This study underscores the need to include the type of culture medium in the development of morphokinetic-based embryo selection tools.

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.

Oocyte quality and embryo selection strategies: a review for the embryologists, by the embryologists

With the advance of assisted reproduction techniques, and the trend towards blastocyst culture and single embryo transfer, gamete and embryo assessment have gained greater importance in ART treatment. Embryo quality depends mainly on gamete quality and culture conditions. Oocyte maturity identification is necessary in order to plan fertilization timing. Mature oocytes at the metaphase II stage show a higher fertilization rate compared to immature oocytes. Morphology assessment is a critical yet challenging task that may serve as a good prognostic tool for future development and implantation potential if done effectively. Various grading systems have been suggested to assess embryos at pronuclear, cleavage, and blastocyst stages. By identifying the embryo with the highest implantation potential, it is possible to reduce the number of embryos transferred without compromising the chances of a successful pregnancy. Apart from the conventional morphology assessment, there are several invasive or non-invasive methods for embryo selection such as preimplantation genetic testing, morphokinetics, proteomics, metabolomics, oxygen consumption, and measurement of oxidative stress in culture medium. Morphokinetics is a method based on time-lapse technology and continuous monitoring of embryos. In this review, we aim to describe and compare the most effective and widely used methods for gamete and embryo assessment as well as embryo selection.

Can Time-Lapse Incubation and Monitoring Be Beneficial to Assisted Reproduction Technology Outcomes? A Randomized Controlled Trial Using Day 3 Double Embryo Transfer

Objective: To determine if the application of time-lapse incubation and monitoring can be beneficial to clinical outcomes in assisted reproductive technology.

Methods: A total of 600 patients were equally randomized to three groups, namely, conventional embryo culture and standard morphological selection (CM group), time-lapse culture and standard morphological selection (TLM group), and time-lapse culture and morphokinetic selection (TLA group). Notably, 424 undergoing fresh autologous in vitro fertilization cycles were analyzed, 132 patients in the CM group, 158 in the TLM group, and 134 in the TLA group. Main outcomes included clinical outcomes, embryo development rates, and perinatal outcomes.

Results: Clinical pregnancy rates in the time-lapse groups were significantly higher than in the CM group (CM 65.2% vs. TLM 77.2% vs. TLA 81.3%). Implantation rates and live birth rates were significantly higher for the TLA group (59.7 and 70.9%) compared with the CM group (47.7 and 56.1%) but not compared with the TLM group (55.4 and 67.1%). There was no statistical difference in miscarriage and ectopic pregnancy rates among the three groups. Overall, birth weight was significantly higher in the time-lapse groups (CM 2,731.7 ± 644.8 g vs. TLM 3,066.5 ± 595.4 g vs. TLA 2,967.4 ± 590.0 g). The birth height of newborns in the TLM group was significantly longer than that of the CM group and TLA group (CM 48.3± 4.4 cm vs. TLM 49.8± 2.3 cm vs. TLA 48.5± 2.7 cm).

Conclusion: Time-lapse incubation and monitoring have a significant benefit on clinical pregnancy rates and on overall birth weights while morphokinetic analysis is not necessary.

Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [NCT02974517].

Using deep learning to predict the outcome of live birth from more than 10,000 embryo data

Background

Recently, the combination of deep learning and time-lapse imaging provides an objective, standard and scientific solution for embryo selection. However, the reported studies were based on blastocyst formation or clinical pregnancy as the end point. To the best of our knowledge, there is no predictive model that uses the outcome of live birth as the predictive end point. Can a deep learning model predict the probability of live birth from time-lapse system?

Methods

This study retrospectively analyzed the time-lapse data and live birth outcomes of embryos samples from January 2018 to November 2019. We used the SGD optimizer with an initial learning rate of 0.025 and cosine learning rate reduction strategy. The network is randomly initialized and trained for 200 epochs from scratch. The model is quantitively evaluated over a hold-out test and a 5-fold cross-validation by the average area under the curve (AUC) of the receiver operating characteristic (ROC) curve.

Results

The deep learning model was able to predict live birth outcomes from time-lapse images with an AUC of 0.968 in 5-fold stratified cross-validation.

Conclusions

This research reported a deep learning model that predicts the live birth outcome of a single blastocyst transfer. This efficient model for predicting the outcome of live births can automatically analyze the time-lapse images of the patient’s embryos without the need for manual embryo annotation and evaluation, and then give a live birth prediction score for each embryo, and sort the embryos by the predicted value.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04373-5.

Time-Lapse Systems: A Comprehensive Analysis on Effectiveness

Time-lapse systems have quickly become a common feature of in vitro fertilization laboratories all over the world. Since being introduced over a decade ago, the alleged benefits of time-lapse technology have continued to grow, from undisturbed culture conditions and round the clock, noninvasive observations to more recent computer-assisted selection of embryos through the development of algorithms. Despite the global uptake of time-lapse technology, its real impact on clinical outcomes is still controversial. This review aims to explore the different features offered by time-lapse technology, discussing incubation, algorithms, artificial intelligence and the regulation of nonessential treatment interventions, while assessing evidence on whether any benefit is offered over conventional technology.

OUP accepted manuscript

STUDY QUESTION

Can use of a commercially available time-lapse algorithm for Day 5 blastocyst selection improve pregnancy rates compared with morphology alone?

SUMMARY ANSWER

The use of a time-lapse selection model to choose blastocysts for fresh single embryo transfer on Day 5 did not improve ongoing pregnancy rate compared to morphology alone.

WHAT IS KNOWN ALREADY

Evidence from time-lapse monitoring suggests correlations between timing of key developmental events and embryo viability. No good quality evidence exists to support improved pregnancy rates following time-lapse selection.

STUDY DESIGN, SIZE, DURATION

A prospective multicenter randomized controlled trial including 776 randomized patients was performed between 2018 and 2021. Patients with at least two good quality blastocysts on Day 5 were allocated by a computer randomization program in a proportion of 1:1 into either the control group, whereby single blastocysts were selected for transfer by morphology alone, or the intervention group whereby final selection was decided by a commercially available time-lapse model. The embryologists at the time of blastocyst morphological scoring were blinded to which study group the patients would be randomized, and the physician and patients were blind to which group they were allocated until after the primary outcome was known. The primary outcome was number of ongoing pregnancies in the two groups.

PARTICIPANTS/MATERIALS, SETTING, METHODS

From 10 Nordic IVF clinics, 776 patients with a minimum of two good quality blastocysts on Day 5 (D5) were randomized into one of the two study groups. A commercial time-lapse model decided the final selection of blastocysts for 387 patients in the intervention (time-lapse) group, and blastocysts with the highest morphological score were transferred for 389 patients in the control group. Only single embryo transfers in fresh cycles were performed.

MAIN RESULTS AND THE ROLE OF CHANCE

In the full analysis set, the ongoing pregnancy rate for the time-lapse group was 47.4% (175/369) and 48.1% (181/376) in the control group. No statistically significant difference was found between the two groups: mean difference −0.7% (95% CI −8.2, 6.7, P = 0.90). Pregnancy rate (60.2% versus 59.0%, mean difference 1.1%, 95% CI −6.2, 8.4, P = 0.81) and early pregnancy loss (21.2% versus 18.5%, mean difference 2.7%, 95% CI −5.2, 10.6, P = 0.55) were the same for the time-lapse and the control group. Subgroup analyses showed that patient and treatment characteristics did not significantly affect the commercial time-lapse model D5 performance. In the time-lapse group, the choice of best blastocyst changed on 42% of occasions (154/369, 95% CI 36.9, 47.2) after the algorithm was applied, and this rate was similar for most treatment clinics.

LIMITATIONS, REASONS FOR CAUTION

During 2020, the patient recruitment rate slowed down at participating clinics owing to coronavirus disease-19 restrictions, so the target sample size was not achieved as planned and it was decided to stop the trial prematurely. The study only investigated embryo selection at the blastocyst stage on D5 in fresh IVF transfer cycles. In addition, only blastocysts of good morphological quality were considered for transfer, limiting the number of embryos for selection in both groups: also, it could be argued that this manual preselection of blastocysts limits the theoretical selection power of time-lapse, as well as restricting the results mainly to a good prognosis patient group. Most patients were aimed for blastocyst stage transfer when a minimum of five zygotes were available for extended culture. Finally, the primary clinical outcome evaluated was pregnancy to only 6–8 weeks.

WIDER IMPLICATIONS OF THE FINDINGS

The study suggests that time-lapse selection with a commercially available time-lapse model does not increase chance of ongoing pregnancy after single blastocyst transfer on Day 5 compared to morphology alone.

STUDY FUNDING/COMPETING INTEREST(S)

The study was financed by a grant from the Swedish state under the ALF-agreement between the Swedish government and the county councils (ALFGBG-723141). Vitrolife supported the study with embryo culture dishes and culture media. During the study period, T.H. changed his employment from Livio AB to Vitrolife AB. All other authors have no conflicts of interests to disclose.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov registration number NCT03445923.

TRIAL REGISTRATION DATE

26 February 2018.

DATE OF FIRST PATIENT’S ENROLMENT

11 June 2018.

Evaluation of artificial intelligence using time-lapse images of IVF embryos to predict live birth

RESEARCH QUESTION

Can artificial intelligence (AI) improve the prediction of live births based on embryo images?

DESIGN

The AI system was created by using the Attention Branch Network associated with deep learning to predict the probability of live birth from 141,444 images recorded by time-lapse imaging of 470 transferred embryos, of which 91 resulted in live birth and 379 resulted in non-live birth that included implantation failure, biochemical pregnancy and clinical miscarriage. The possibility that the calculated confidence scores of each embryo and the focused areas visualized in each embryo image can help predict subsequent live birth was examined.

RESULTS

The AI system for the first time successfully visualized embryo features in focused areas that had potential to distinguish between live and non-live births. No visual feature of embryos were visualized that were associated with live or non-live births, although there were many images in which high-focused areas existed around the zona pellucida. When a cut-off level for the confidence score was set at 0.341, the live birth rate was significantly greater for embryos with a score higher than the cut-off level than for those with a score lower than the cut-off level (P < 0.001). In addition, the live birth rate of embryos with good morphological quality and confidence scores higher than 0.341 was 41.1%.

CONCLUSIONS

The authors have created an AI system with a confidence score that is useful for non-invasive selection of embryos that could result in live birth. Further study is necessary to improve selection accuracy.

Change in the Strategy of Embryo Selection with Time-Lapse System Implementation-Impact on Clinical Pregnancy Rates

Time-lapse systems (TLS) and associated algorithms are interesting tools to improve embryo selection. This study aimed to evaluate how TLS and KIDScore™ algorithm changed our practices of embryo selection, as compared to a conventional morphological evaluation, and improved clinical pregnancy rates (CPR). In the study group (year 2020, n = 303 transfers), embryos were cultured in an EmbryoScope+ time-lapse incubator. A first team observed embryos conventionally once a day, while a second team selected the embryos for transfer based on time-lapse recordings. In the control group (year 2019, n = 279 transfers), embryos were selected using the conventional method, and CPR were recorded. In 2020, disagreement between TLS and the conventional method occurred in 32.1% of transfers, more often for early embryos (34.7%) than for blastocysts (20.5%). Irregular morphokinetic events (direct or reverse cleavage, multinucleation, abnormal pronuclei) were detected in 54.9% of the discordant embryos. When it was available, KIDScore™ was decreased for 73.2% of the deselected embryos. Discordant blastocysts mainly corresponded with a decrease in KIDScore™ (90.9%), whereas discordant Day 3 embryos resulted from a decreased KIDScore™ and/or an irregular morphokinetic event. CPR was significantly improved in the TLS group (2020), as compared to the conventional group (2019) (32.3% vs. 21.9%, p = 0.005), even after multivariate analysis. In conclusion, TLS is useful to highlight some embryo development abnormalities and identify embryos with the highest potential for pregnancy.

Neonatal Outcomes of Embryos Cultured in a Time-Lapse Incubation System: an Analysis of More Than 15,000 Fresh Transfer Cycles

In the past 5 years, the time-lapse culture system (TLS) has gradually been applied to the field of assisted reproduction. However, there are few reports on the comparison between this system and the conventional culture system (CS) on the outcome of newborns. As a new model in embryo culture, we should pay attention to its neonatal outcomes. We examined 15,252 fresh transfer cycles processed between January 2016 and December 2019. After propensity score matching, embryos in two groups, TLS and CS, had similar rates of miscarriages, ectopic pregnancy, and live delivery (P > 0.05). Embryos in the TLS group achieved higher clinical pregnancy and implantation rates (P < 0.05). Of the perinatal and neonatal outcomes, singletons and twins were analyzed separately. No significant differences were observed in gestational age, preterm deliveries, birth weight, and sex ratio (P > 0.05). Incidences of malformations of babies delivered from CS and TLS groups were also similar between the two groups. Embryos cultured in a TLS are as safe as CS with regard to neonatal outcomes, including congenital malformations.

Comparison of pregnancy outcomes using a time-lapse monitoring system for embryo incubation versus a conventional incubator in in vitro fertilization: An age-stratification analysis

OBJECTIVE

The aim of this study was to compare the pregnancy outcomes of in vitro fertilization with embryo transfer between embryos cultured in a time-lapse monitoring system (TLS) and those cultured in a conventional incubator (CI).

METHODS

The medical records of 250 fertilized embryos from 141 patients undergoing infertility treatment with assisted reproductive technology at a tertiary hospital from June 2018 to May 2020 were reviewed. The study population was divided into TLS and CI groups at a 1 to 1 ratio (125 embryos per group). The primary outcome was the live birth rate.

RESULTS

The TLS group had a significantly higher clinical pregnancy rate (46.4% vs. 27.2%, p=0.002), implantation rate (27.1% vs. 12.0%, p=0.004), and live birth rate (32.0% vs. 18.4%, p=0.013) than the CI group. Furthermore, subgroup analyses of the clinical pregnancy rate and live birth rate in the different age groups favored the TLS group. However, this difference only reached statistical significance in the live birth rate in women aged over 40 years and the clinical pregnancy rate in women aged 35-40 years (p=0.048 and p=0.031, respectively). The miscarriage rate, cleavage rate, and blastocyst rate were comparable.

CONCLUSION

TLS application improved the live birth rate, implantation rate, and clinical pregnancy rate, particularly in the advanced age group in this study, while the other reproductive outcomes were comparable. Large randomized controlled trials are needed to further explore the ramifications of these findings, especially in different age groups.

Single-embryo transfer: a key strategy to reduce the risk for multiple pregnancy in assisted human reproduction

In the early days of assisted reproductive technology (ART), the main target was achieving gestation. Success rates were low, and multiple embryo transfers became common practice, with multiple pregnancies being 20 times higher than in natural conception. Multiple pregnancy is associated with a higher risk of complications for the mother and the baby than a singleton pregnancy. Added to healthcare costs, multiple pregnancy also involves other costs and psychosocial risks, with a high social and health costs. At present, success rates of assisted human reproduction (AHR) have improved dramatically, partially due to advances in laboratory techniques such as culture of blastocyst-stage embryos and vitrification. Additionally, there is a wide range of counseling, health and economic policies that have demonstrated being effective in increasing single-embryo transfer (SET) practices and reducing multiple pregnancies, which ensures satisfactory success rates. Therefore, single-embryo transfer emerges as the approach of choice for AHR to result in a full-term healthy newborn.

Early embryo morphokinetics is a better predictor of post-ICSI live birth than embryo morphology: speed is more important than beauty at the cleavage stage

Given the importance of embryo developmental competence assessment in reproductive medicine and biology, the aim of this study was to compare the performance of fertilization and cleavage morphokinetics with embryo morphology to predict post-ICSI live birth. Data from embryos cultured in a time-lapse microscopy (TLM) incubator and with known live birth outcomes (LB: embryos achieving live birth, n = 168; NLB: embryos not achieving live birth, n = 1633) were used to generate receiver operating characteristic (ROC) curves based on morphokinetic or morphological scores, and the respective areas under the curve (AUC) were compared. The association between live birth and 12 combinations of four morphokinetic quality degrees (A-D) with three morphological quality degrees (A-C) was assessed using multivariate analysis. Morphokinetic parameters from tPNa to t8 were reached earlier in LB compared with NLB embryos. The ROC curve analysis indicated that morphokinetic information is more accurate than conventional morphology to predict live birth [AUC = 0.64 (95% CI 0.58-0.70) versus AUC = 0.58 (95% CI 0.51-0.65)]. The multivariate analysis was in line with AUCs, revealing that embryos with poor morphokinetics, independently of their morphology, provide lower live birth rates (P < 0.001). A considerable percentage of embryos with top morphology presented poor morphokinetics (20.10%), accompanied by a severely reduced live birth rate in comparison with embryos with top morphology and morphokinetics (P < 0.001). In conclusion, TLM-derived early morphokinetic parameters were more predictive of live-birth achievement following ICSI than conventional morphology.

Prenatal growth trajectories and birth outcomes after frozen-thawed extended culture embryo transfer and fresh embryo transfer: the Rotterdam Periconception Cohort

RESEARCH QUESTION

Are there differences in prenatal growth trajectories and birth outcomes between singleton pregnancies conceived after IVF treatment with frozen-thawed extended culture embryo transfer at day 5, fresh embryo transfer at day 3 or naturally conceived pregnancies?

DESIGN

From a prospective hospital-based cohort, 859 singleton pregnancies were selected, including 133 conceived after IVF with frozen-thawed embryo transfer, 276 after fresh embryo transfer, and 450 naturally conceived pregnancies. Longitudinal 3D ultrasound scans were performed at 7, 9 and 11 weeks of gestation for offline crown-rump length (CRL) and embryonic volume measurements. Second trimester estimated fetal weight was based on growth parameters obtained during the routine fetal anomaly scan at 20 weeks of gestation. Birth outcome data were collected from medical records.

RESULTS

No differences regarding embryonic growth trajectories were observed between frozen-thawed and fresh embryo transfer. Birthweight percentiles after fresh embryo transfer were lower than after frozen-thawed embryo transfer (38.0 versus 48.0; P = 0.046, respectively). The prevalence of non-iatrogenic preterm birth (PTB) was significantly lower in pregnancies resulting from fresh embryo transfer compared with frozen-thawed embryo transfer (4.7% versus 10.9%; P = 0.026, respectively). Compared with naturally conceived pregnancies, birthweight percentiles and percentage of non-iatrogenic PTB were significantly lower in pregnancies after fresh embryo transfer and gestational age at birth was significantly higher.

CONCLUSIONS

This study shows that embryonic growth is comparable between singleton pregnancies conceived after fresh and frozen-thawed embryo transfer. The lower relative birthweight and PTB rate in pregnancies after fresh embryo transfer than after frozen-thawed embryo transfer and naturally conceived pregnancies warrants further investigation.

Outcome of in vitro fertilization cycles with automatic time-lapse instrumentation combined with the early embryo viability assessment score

AIM

To evaluate whether embryo selection using the early embryo viability assessment (EEVA) score increases the ongoing pregnancy rate of in vitro fertilization and intracytoplasmic sperm injection patients.

METHODS

One hundred eighty-one patients whose serum anti mullerian hormone (AMH) level was greater than 0.5 ng/μL were enrolled in the study. All patients received oocyte retrieval repeatedly from June 2017 to January 2019. Transferred embryos were selected using the EEVA score and Veeck's criteria. We investigated the blastocyst rate according to the EEVA score and Veeck's criteria and also evaluated the clinical outcome following embryo transfer of the blastocysts.

RESULTS

Blastocyst development rate (48.7%) and high-quality blastocyst (42.4%) of Veeck 1 was statistically higher than others. The blastocyst rate (71.4%) and high-quality blastocyst rate (60.0%) for EEVA 1 was the highest, and a correlation between the EEVA score and the blastocyst rate was also identified in cases younger than 40 years. Blastocyst rate of EEVA 1 + 2 (69.8% 208/298) was statistically higher than that of Veeck 1 + 2 (40.1% 317/791) (p < 0.05) and high-quality blastocyst rate of EEVA 1 + 2 (50.0% 104/208) was also higher than that of Veeck 1 + 2 (36.6% 117/320) (p < 0.05). However, there was a significant correlation between EEVA and the pregnancy rate and pregnancy rate of EEVA 1 + 2 showed no statistical difference compared with Veeck 1 + 2.

CONCLUSIONS

Although it remains to be answered whether a computer can substitute Veeck's classification, the EEVA score could be a viable alternative to predict the blastocyst rate and to select those high-potential embryos that improve the pregnancy rate.

Time-lapse technology improves total cumulative live birth rate and shortens time to live birth as compared to conventional incubation system in couples undergoing ICSI

PURPOSE

The improvement of clinical outcome provided by time-lapse technology (TLT) in IVF over conventional incubation (CI) still remains controversial. This study aimed at evaluating whether the exclusive use of time-lapse technology (TLT) during whole IVF care improves total cumulative live birth rate (TCLBR) and shortens time to live birth (TTLB) as compared to the use of CI in couples undergoing ICSI.

METHODS

This retrospective cohort study was conducted in couples with male infertility undergoing their first ICSI cycle in 2014-2015 and for whom embryo culture system remained the same during their whole IVF care, i.e., TLT or CI. Couples were followed up up to 2020, including all following frozen-embryo transfers and ICSI cycles (if any). Survival analysis was used to compare clinical outcome and time-related endpoints between both groups.

RESULTS

A total of 151 and 250 couples underwent their whole IVF care with the exclusive use of TLT and CI, respectively. Survival analysis showed that TCLBR after whole IVF care was significantly higher in TLT than in CI group (66.9 vs 56.4%, p=0.02, log-rank test). Median live birth time was significantly shorter in TLT than CI group (464 vs 596 days, p=0.01).

CONCLUSIONS

We found that TCLBR and TTLB were significantly improved with TLT over CI in couples undergoing ICSI for male factor. This study fuels the debate on the clinical benefit of using TLT. The use of time-related endpoints adds important information for both patients and practitioners.

A machine learning system with reinforcement capacity for predicting the fate of an ART embryo

The aim of this work was to construct a score issued from a machine learning system with self-improvement capacity able to predict the fate of an ART embryo incubated in a time lapse monitoring (TLM) system. A retrospective study was performed. For the training data group, 110 couples were included and, 891 embryos were cultured. For the global setting data group, 201 couples were included, and 1186 embryos were cultured. No image analysis was used; morphokinetic parameters from the first three days of embryo culture were used to perform a logistic regression between the cell number and time. A score named DynScore was constructed, the prediction power of the DynScore on blastocyst formation and the baby delivery were tested via the area under the curve (AUC) obtained from the receiver operating characteristic (ROC). In the training data group, the DynScore allowed the blastocyst formation prediction (AUC = 0.634, p < 0.001), this approach was the higher among the set of the tested scores. Similar results were found with the global setting data group (AUC = 0.638, p < 0.001) and it was possible to increase the AUC of the DynScore with a regular update of the prediction system by reinforcement, with an AUC able to reach a value above 0.9. As only the best blastocysts were transferred, none of the tested scores was able to predict delivery. In conclusion, the DynScore seems to be able to predict the fate of an embryo. The reinforcement of the prediction system allows maintaining the predictive capacity of DynScore irrespective of the various events that may occur during the ART process. The DynScore could be implemented in any TLM system and adapted by itself to the data of any ART center.Abbreviations: ART: assisted reproduction technology; TLM: time lapse monitoring system; AUC: area under the curve; ROC: receiver operating characteristic; eSET: elective single embryo transfer; AIS: artificial intelligence system; KID: known implantation data; AMH: anti-Müllerian hormone; BMI: body mass index; WHO: World Health Organization; c-IVF: conventional in-vitro fertilization; ICSI: intracytoplasmic sperm injection; PNf: pronuclear formation; D3: day 3; D5: day 5; D6: day 6; GnRH: gonadotrophin releasing hormone; FSH: follicle stimulating hormone; LH: luteinizing hormone; hCG: human chorionic gonadotropin; PVP: polyvinyl pyrrolidone; PNf: time of pronuclear fading; tx: time of cleavage to x blastomeres embryo; ICM: inner cell mass; TE: trophectoderm; NbCell_t: number of cells at t time; FIFO: first in first out; TD: training data group; SD: setting data group; R: real world.

Comparison of single euploid blastocyst transfer cycle outcome derived from embryos with normal or abnormal cleavage patterns

RESEARCH QUESTION

To assess incidence of abnormal cleavage among biopsied blastocysts; to compare euploidy rates of the blastocysts with abnormal and normal cleavage; and to compare single euploid blastocyst transfer (SEBT) outcome derived from embryos with normal or abnormal cleavage.

DESIGN

Retrospective analysis of prospectively collected data in a private IVF clinic. Consecutive 554 patients (749 cycles) undergoing preimplantation genetic testing for aneuploidy (n = 497; 671 cycles) or monogenic diseases (n = 57; 78 cycles) were included. All assessments for abnormal cleavage were carried out retrospectively; presence of abnormal cleavage was not a factor in deciding which euploid embryo to transfer. A total of 1015 blastocysts were biopsied and 295 SEBT procedures were carried out. Main outcome measure was live birth rate (LBR).

RESULTS

Incidence of reverse cleavage, direct cleavage, and reverse plus direct cleavage, were 7.7%, 6.4% and 2.3%, respectively. Of the 1015 biopsied blastocysts, 35.0% were euploid. Blastocysts with abnormal cleavage, in total, had a significantly higher euploidy rate compared with blastocysts with normal cleavage (44.6% [74/166] versus 33.1% [281/849]; P = 0.017). The LBR after SEBT with normal, reverse and direct cleavage, and direct cleavage plus reverse cleavage, was 133/238 (55.9%), 6/26 (23.1%), 8/24 (33.3%) and 0/3 (0.0%) (P < 0.001). Generalized estimating equation analysis showed that the presence of abnormal cleavage pattern was the only independent predictor of LBR (OR 0.316; 95% CI 0.115 to 0.867; P = 0.013).

CONCLUSIONS

Blastocysts with direct or reverse cleavage should be biopsied in preimplantation genetic testing cycles if they are morphologically eligible. Euploid blastocysts with abnormal cleavage, however, have approximately half the LBR of those euploid blastocyst with normal cleavage, hence, blastocysts with abnormal cleavage should have lower priority for transfer.

Time-lapse technology improves total cumulative live birth rate and shortens time to live birth as compared to conventional incubation system in couples undergoing ICSI

PURPOSE

The improvement of clinical outcome provided by time-lapse technology (TLT) in IVF over conventional incubation (CI) still remains controversial. This study aimed at evaluating whether the exclusive use of time-lapse technology (TLT) during whole IVF care improves total cumulative live birth rate (TCLBR) and shortens time to live birth (TTLB) as compared to the use of CI in couples undergoing ICSI.

METHODS

This retrospective cohort study was conducted in couples with male infertility undergoing their first ICSI cycle in 2014-2015 and for whom embryo culture system remained the same during their whole IVF care, i.e., TLT or CI. Couples were followed up up to 2020, including all following frozen-embryo transfers and ICSI cycles (if any). Survival analysis was used to compare clinical outcome and time-related endpoints between both groups.

RESULTS

A total of 151 and 250 couples underwent their whole IVF care with the exclusive use of TLT and CI, respectively. Survival analysis showed that TCLBR after whole IVF care was significantly higher in TLT than in CI group (66.9 vs 56.4%, p=0.02, log-rank test). Median live birth time was significantly shorter in TLT than CI group (464 vs 596 days, p=0.01).

CONCLUSIONS

We found that TCLBR and TTLB were significantly improved with TLT over CI in couples undergoing ICSI for male factor. This study fuels the debate on the clinical benefit of using TLT. The use of time-related endpoints adds important information for both patients and practitioners.