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

A generalized AI system for human embryo selection covering the entire IVF cycle via multi-modal contrastive learning

In vitro fertilization (IVF) has revolutionized infertility treatment, benefiting millions of couples worldwide. However, current clinical practices for embryo selection rely heavily on visual inspection of morphology, which is highly variable and experience dependent. Here, we propose a comprehensive artificial intelligence (AI) system that can interpret embryo-developmental knowledge encoded in vast unlabeled multi-modal datasets and provide personalized embryo selection. This AI platform consists of a transformer-based network backbone named IVFormer and a self-supervised learning framework, VTCLR (visual-temporal contrastive learning of representations), for training multi-modal embryo representations pre-trained on large and unlabeled data. When evaluated on clinical scenarios covering the entire IVF cycle, our pre-trained AI model demonstrates accurate and reliable performance on euploidy ranking and live-birth occurrence prediction. For AI vs. physician for euploidy ranking, our model achieved superior performance across all score categories. The results demonstrate the potential of the AI system as a non-invasive, efficient, and cost-effective tool to improve embryo selection and IVF outcomes.

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.

The impact of oocyte central granularity on ICSI practice: developmental competence of dysmorphic and morphologically normal companion oocytes

PURPOSE

To assess the effects of oocyte central granularity and its underlying endocrine environment on developmental competence of dysmorphic and morphologically normal oocytes.

METHODS

Retrospective cohort study including 1,082 patients undergoing autologous ICSI cycles. Of these, 211 patients provided 602 oocytes with central granularity (CG) and 427 morphologically normal cycle companion oocytes (NCG). The remaining 871 patients provided only morphologically normal oocytes in cycles not yielding dysmorphic oocytes (N). Patient profile associated with CG was characterized, and fertilization rates, early morphokinetics and live birth rates were compared between N, CG and NCG groups. Patient characteristics associated with implantation and delivery performance of CG-derived embryos were assessed.

RESULTS

CG was associated with higher maternal age, basal FSH concentrations and total FSH dose, but with lower circulating AMH (p ≤ 0.035). Fertilization rates were reduced and early morphokinetic parameters were delayed in CG (p < 0.025) and NCG (p < 0.05) groups as compared to the N group. Embryos derived from CG oocytes achieved a markedly lower live birth rate (14.9%) as compared to those derived from NCG (36.8%; p = 0.03) and N oocytes (29.8%; p = 0.002). The negative relationship between CG and live birth was confirmed by a multivariate analysis controlling for potential confounders (OR:2.59, IC:1.27-5.31; P = 0.009). Implantation and delivery rates following transfers of CG-derived embryos were inversely associated with maternal age.

CONCLUSION

CG oocytes, but not their morphologically normal cycle companions, have severely compromised developmental competence. Maternal age should be a key parameter in deciding whether or not to utilize CG oocytes in ICSI cycles.

The impact of endometriosis on embryo morphokinetics: embryos from endometriosis patients exhibit delayed cell cycle milestones and decreased blastulation rates

PURPOSE

To compare morphokinetic parameters in embryos obtained from women with and without endometriosis.

METHODS

We evaluated a total of 3471 embryos resulting from 434 oocyte retrievals performed at a single academic center. One thousand seventy-eight embryos were obtained from women affected by endometriosis and 2393 came from unaffected controls. All embryos were cultured in a time-lapse incubator chamber for up to 6 days. IVF cycle outcomes and morphokinetic parameters collected prospectively were retrospectively reviewed.

RESULTS

Morphokinetic data suggest that embryo development is impaired in embryos obtained from women with endometriosis (EE). EE were slower to achieve the 2-8 cell stages compared to control embryos (CE) (p < 0.001); additionally, time to compaction was delayed compared to CE (p = 0.015). The timing of late developmental events, including morulation and blastulation was also delayed in the endometriosis cohort (p < 0.001). In addition to demonstrating delayed cell cycle milestones, EE were less likely than controls to progress to morula, blastocyst, and expanded blastocyst stages (p < 0.001). Furthermore, a smaller proportion of embryos in the endometriosis group fell into optimal kinetic ranges for cc2 (p = 0.003), t5 (p = 0.019), tSB (p < 0.001), and tEB (p = 0.007). There were no significant differences in clinical pregnancy or live birth rates between groups.

CONCLUSION

Embryos from endometriosis patients demonstrate impairments in both early and late developmental events, and progress to the morula, blastocyst, and expanded blastocyst stages at lower rates than control embryos. Despite these differences, IVF outcomes are similar for patients with and without endometriosis.

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.

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.

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.

The clinical use of time-lapse in human-assisted reproduction

A major challenge in the assisted reproduction laboratory is to set up reproducible and efficient criteria to identify the embryo with the highest developmental potential. Over the years, several methods have been used worldwide with this purpose. Initially, standard morphology assessment was the only available strategy. It is now universally recognized that besides being a very subjective embryo selection strategy, morphology evaluation alone has a very poor prognostic value. More recently, the availability of time-lapse incubators allowed a continuous monitoring of human embryo development. This technology has spread quickly and many fertility clinics over the world produced a remarkable amount of data. To date, however, a general consensus on which variables, or combination of variables, should play a central role in embryo selection is still lacking. Many confounding factors, concerning both patient features and clinical and biological procedures, have been observed to influence embryo development. In addition, several studies have reported unexpected positive outcomes, even in the presence of abnormal developmental criteria. While it does not seem that time-lapse technology is ready to entirely replace the more invasive preimplantation genetic testing in identifying the embryo with the highest implantation potential, it is certainly true that its application is rapidly growing, becoming progressively more accurate. Studies involving artificial intelligence and deep-learning models as well as combining morphokinetic with other non-invasive markers of embryo development, are currently ongoing, raising hopes for its successful applicability for clinical purpose in the near future. The present review mainly focuses on data published starting from the first decade of 2000, when time-lapse technology was introduced as a routine clinical practice in the infertility centers.

Optical imaging of cleavage stage bovine embryos using hyperspectral and confocal approaches reveals metabolic differences between on-time and fast-developing embryos

The assessment of embryo quality aims to enhance subsequent pregnancy and live birth outcomes. Metabolic analysis of embryos has immense potential in this regard. As a step towards this goal, here we assess the metabolism of bovine embryos using label-free optical imaging. We compared embryos defined as either on-time or fast-developing, as fast dividing embryos are more likely to develop to the blastocyst stage. Specifically, bovine embryos at 48 (Day 2) and 96 (Day 4) hours post fertilization were fixed and separated based on morphological assessment: on-time (Day 2: 2 cell; Day 4: 5-7 cell) or fast-developing (Day 2: 3-7 cell; Day 4: 8-16 cell). Embryos with different developmental rates on Day 2 and Day 4 were correlated with metabolic activity and DNA damage. Confocal microscopy was used to assess metabolic activity by quantification of cellular autofluorescence specific for the endogenous fluorophores NAD(P)H and FAD with a subsequent calculation of the optical redox ratio. Separately, hyperspectral microscopy was employed to assess a broader range of endogenous fluorophores. DNA damage was determined using γH2AX immunohistochemistry. Hyperspectral imaging showed significantly lower abundance of endogenous fluorophores in fast-developing compared to on-time embryos on Day 2, indicating a lower metabolic activity. On Day 4 of development there was no difference in the abundance of FAD between on-time and fast-developing embryos. There was, however, significantly higher levels of NAD(P)H in fast-developing embryos leading to a significantly lower optical redox ratio when compared to on-time embryos. Collectively, these results demonstrate that fast-developing embryos present a 'quiet' metabolic pattern on Day 2 and Day 4 of development, compared to on-time embryos. There was no difference in the level of DNA damage between on-time and fast-developing embryos on either day of development. To our knowledge, this is the first collective use of confocal and hyperspectral imaging in cleavage-stage bovine embryos in the absence of fluorescent tags.

Association between early embryo morphokinetics plus transcript levels of sperm apoptotic genes and clinical outcomes in IMSI and ICSI cycles of male factor patients

PURPOSE

The aim was to assess the correlation of sperm apoptotic transcript levels with cleavage stage embryokinetic and pregnancy outcomes of intracytoplasmic morphologically selected sperm injection (IMSI) and ICSI methods in patients with male factor infertility.

MATERIAL AND METHODS

Eighty male factor cases were divided into ICSI and IMSI groups. ICSI was done routinely, and for IMSI, sperm was selected at high magnification and injected. On day 3, time-lapse parameters were evaluated, and the best embryos were transferred and followed to delivery. In addition, sperm DNA fragmentation and apoptotic transcript levels were quantified using reverse transcription Q-PCR between the groups.

RESULTS

IMSI selected spermatozoa had lower DNA fragmentation and apoptotic transcript levels compared with ICSI (p < 0.0001). Moreover, all cytokinetic variables and cleavage abnormalities were noticeably different between groups (p < 0.0001); the rates of clinical outcomes were higher in the IMSI group. The transcript levels of Caspase 3 showed a moderate negative correlation with s2 and s3 (rs = - 0.57, P = 0.008 and rs = - 0.51, p = 0.021, respectively) in the IMSI group. However, there was no relationship between sperm apoptotic transcript levels and clinical outcomes in two groups.

CONCLUSIONS

Sperms selected at high magnification showed lower DNA fragmentation and apoptosis genes transcript. Also, better embryo kinetics and clinical outcomes were confirmed in IMSI than ICSI groups. Some time-lapse parameters may be associated with transcript levels of apoptosis genes. Therefore, these noninvasive techniques may be unique in assisting couples with male factor infertility.

TRIAL REGISTRATION

This trial retrospectively registered on 4 July 2020 (IRCT20180130038561N1).

Time-lapse imaging: the state of the art†

The introduction of time-lapse imaging to clinical in vitro fertilization practice enabled the undisturbed monitoring of embryos throughout the entire culture period. Initially, the main objective was to achieve a better embryo development. However, this technology also provided an insight into the novel concept of morphokinetics, parameters regarding embryo cell dynamics. The vast amount of data obtained defined the optimal ranges in the cell-cycle lengths at different stages of embryo development. This added valuable information to embryo assessment prior to transfer. Kinetic markers became part of embryo evaluation strategies with the potential to increase the chances of clinical success. However, none of them has been established as an international standard. The present work aims at describing new approaches into time-lapse: progress to date, challenges, and possible future directions.

Impact of sperm characteristics on time-lapse embryo morphokinetic parameters and clinical outcome of conventional in vitro fertilization

BACKGROUND

Sperm abnormalities may negatively affect embryo development.

OBJECTIVES

To determine the influence of sperm abnormalities (morphology, motility, DNA fragmentation) on embryo morphokinetic variables and clinical outcome of conventional IVF.

MATERIALS AND METHODS

Participants were 86 couples undergoing in vitro fertilization (IVF). Sperm morphology was evaluated according to the strict criteria proposed by Kruger/Tygerberg. CASA system was applied for sperm motility assessment. Sperm DNA fragmentation was assessed by the chromatin structure assay (SCSA). Morphokinetic parameters were determined in 223 embryos obtained from conventional IVF only and cultured in a single-step medium using time-lapse imaging technology.

RESULTS

Time-lapse variables from the initial embryo development, such as time of pronuclei fading (tPNf) and time for two cells (t2), were those more strongly related with abnormalities of sperm motility, morphology, and DNA fragmentation. Sperm morphological abnormalities rather than sperm motility were more closely associated with embryo morphokinetics. Sperm head defects were mainly correlated with the last stages of embryonic development (t9 to tHB), sperm midpiece defects with intermediate cleaving embryos (t5-t9), and sperm tail defects with the initial stages of embryonic development (tPNa-t4). Excess residual cytoplasm was positively correlated with all embryo morphokinetic parameters except t2 and tM. Absence of acrosomes, pinheads, coiled tails, and multiple sperm morphological defects correlated negatively with time-lapse embryo morphokinetic variables.

DISCUSSION

A large number of sperm-related variables, including frequency of specific morphological defects, morphological indexes, DNA fragmentation and motility, and time-lapse embryo variables, such as time intervals based mainly of 15 time points were recorded.

CONCLUSION

There were strong associations between specific sperm defects of the head, midpiece, and tail with certain stages of embryonic development from observation of pronuclei to the hatched blastocyst. Coiled tail, cumulative head defects, and multiple abnormalities index (MAI) were associated both with embryo morphokinetics and the implantation success.

Effect of embryo selection based morphokinetics on IVF/ICSI outcomes: evidence from a systematic review and meta-analysis of randomized controlled trials

PURPOSE

Debate exists for the optimal tool to select embryos for transfer in assisted reproductive technology (ART). Time-lapse monitoring (TLM) is a noninvasive tool suggested where each embryo can be captured every 5-20 min. Given the inconsistency in the existing studies, we conducted this meta-analysis of RCTs to summarize the evidence available concerning the predictive ability of morphokinetics compared with the routine assessment of embryo development in ART.

METHODS

The primary databases MEDLINE, EMBASE, Cochrane, NHS, WHO, and Other Non-Indexed Citations were consulted for RCTs that have been published until November 2018, with no language restriction.

RESULTS AND CONCLUSION

Our review includes 6 RCTs (n = 2057 patients). The data showed an improvement (~ 9%) in live birth TLM (OR 1.43; 95% CI 1.10-1.85; P = 0.007), with low-quality evidence. There was no evidence of a significant difference between both groups concerning ongoing pregnancy, clinical pregnancy and implantation rates. The data further showed that morphokinetics is associated with decreased early pregnancy loss rate. These estimates must be interpreted with caution owing to the statistical and clinical heterogeneities and the consequent difficulty in drawing any meaningful conclusion.

Does polycystic ovary syndrome affect morphokinetics or abnormalities in early embryonic development?

OBJECTIVES

This study aimed to investigate whether oocyte retrieval from PCOS patients affects the morphokinetics or the incidence of abnormalities in early embryonic development, using time-lapse imaging analysis.

METHODS

This was a prospective study in total of 39 PCOS patients and 67 women with normal ovarian function, underwent a GnRH antagonist protocol of controlled ovarian stimulation and fertilization by ICSI. 402 zygotes from the PCOS group and 449 zygotes from the control group were observed by time-lapse monitoring for 48 h following sperm injection.

RESULTS

Patients with PCOS showed a significantly higher number of retrieved oocytes, and a significantly higher number of metaphase II oocytes per cycle than that of the non-PCOS group (18.85 ± 9.41 vs. 11.48 ± 5.51 and 14.97 ± 7.43 vs. 9.51 ± 4.7, respectively). However, oocyte maturation rate and morphologically assessed embryo quality did not differ between two groups. After 48 h of the embryo culture using time-lapse video recording, most of the embryos in both groups had reached the 4-cell stage (353/449 vs. 314/402 embryos). There were no significant differences between the control and PCOS group regarding the time-points of the successive events in early embryonic development from the appearance of 2 polar bodies to the 6-cell stage. However, the percentage of t2 stages which fell in "optimal range" (>24 h and ≤28 h) was significantly lower in the PCOS group than in the control group (37.8% vs. 48.1%, P = 0.004). The proportion of embryos manifesting abnormal fertility, multinucleation, direct cleavage and reverse cleavage were not significantly different between the two groups.

CONCLUSION

Our data indicated that PCOS does not affect the morphokinetics or incidence of abnormalities in early embryonic development.

Time-lapse systems for embryo incubation and assessment in assisted reproduction

BACKGROUND

Embryo incubation and assessment is a vital step in assisted reproductive technology (ART). Traditionally, embryo assessment has been achieved by removing embryos from a conventional incubator daily for quality assessment by an embryologist, under a microscope. In recent years time-lapse systems (TLS) have been developed which can take digital images of embryos at frequent time intervals. This allows embryologists, with or without the assistance of embryo selection software, to assess the quality of the embryos without physically removing them from the incubator.The potential advantages of a TLS include the ability to maintain a stable culture environment, therefore limiting the exposure of embryos to changes in gas composition, temperature, and movement. A TLS has the potential advantage of improving embryo selection for ART treatment by utilising additional information gained through continuously monitoring embryo development. Use of a TLS often adds significant extra cost to ART treatment.

OBJECTIVES

To determine the effect of a TLS compared to conventional embryo incubation and assessment on clinical outcomes in couples undergoing ART.

SEARCH METHODS

We used standard methodology recommended by Cochrane. We searched the Cochrane Gynaecology and Fertility (CGF) Group Trials Register, CENTRAL, MEDLINE, Embase, CINAHL, and two trials registers on 7 January 2019 and checked references of appropriate papers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing TLS, with or without embryo selection software, versus conventional incubation with morphological assessment; and TLS with embryo selection software versus TLS without embryo selection software among couples undergoing ART.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. The primary review outcomes were live birth or ongoing pregnancy, miscarriage and stillbirth, and cumulative live birth or ongoing pregnancy rate. The secondary outcomes were clinical pregnancy and cumulative clinical pregnancy. We assessed the quality of the evidence using GRADE methodology. We made the following comparisons.TLS with conventional morphological assessment of still TLS images versus conventional incubation and assessmentTLS utilising embryo selection software versus TLS with conventional morphological assessment of still TLS images TLS utilising embryo selection software versus conventional incubation and assessment MAIN RESULTS: We included nine RCTs (N = 2955 infertile couples). The quality of the evidence ranged from very low to low. The main limitations were high risk of bias in the included studies, imprecision, indirectness, and inconsistency. There were no data on cumulative live birth or ongoing pregnancy rate or cumulative clinical pregnancy rate.TLS with conventional morphological assessment of still TLS images versus conventional incubation and assessmentIt is unclear whether there is any difference between interventions in rates of live birth or ongoing pregnancy (odds ratio (OR) 0.91, 95% confidence interval (CI) 0.67 to 1.23, 3 RCTs, N = 826, I2 = 33%, low-quality evidence) or in miscarriage rates (OR 1.90, 95% CI 0.99 to 3.61, 3 RCTs, N = 826, I2 = 0%, low-quality evidence). The evidence suggests that if the rate of live birth or ongoing pregnancy associated with conventional incubation and assessment is 35%, the rate with the use of TLS with conventional morphological assessment of still TLS images would be between 27% and 40%, and if the miscarriage rate with conventional incubation is 4%, the rate associated with conventional morphological assessment of still TLS images would be between 4% and 14%. It is unclear whether there is a difference between the interventions in rates of stillbirth (OR 1.00, 95% CI 0.13 to 7.49, 1 RCT, N = 76, low-quality evidence) or clinical pregnancy (OR 1.06, 95% CI 0.79 to 1.41, 4 RCTs, N = 875, I2 = 0%, low-quality evidence).TLS utilising embryo selection software versus TLS with conventional morphological assessment of still TLS imagesAll findings for this comparison were very uncertain due to the very low-quality of the evidence. No data were available on live birth, but one RCT reported ongoing pregnancy. It is unclear whether there is any difference between the interventions in rates of ongoing pregnancy (OR 0.61, 95% CI 0.32 to 1.20, 1 RCT, N = 163); miscarriage (OR 1.39, 95% CI 0.64 to 3.01, 2 RCTs, N = 463, I2 = 0%); or clinical pregnancy (OR 0.97, 95% CI 0.67 to 1.42, 2 RCTs, N = 463, I2 = 0%). The evidence suggests that if the rate of ongoing pregnancy associated with TLS with conventional morphological assessment of still TLS images is 47%, the rate associated with TLS utilising embryo selection software would be between 22% and 52%, and if the miscarriage rate associated with conventional morphological assessment of still TLS images is 5%, the rate associated with TLS utilising embryo selection software would be between 4% and 15%. No studies reported stillbirth.TLS utilising embryo selection software versus conventional incubation and assessmentThe findings for this comparison were also very uncertain due to the very low quality of the evidence. It is unclear whether there is any difference between the interventions in rates of live birth (OR 1.12, 95% CI 0.92 to 1.36, 3 RCTs, N = 1617, I2 = 84%). There was very low-quality evidence that TLS might reduce miscarriage rates (OR 0.63, 95% CI 0.45 to 0.89, 3 RCTs, N = 1617, I2 = 0%). It is unclear whether there is any difference between the interventions in rates of clinical pregnancy (OR 0.95, 95% CI 0.78 to 1.16, 3 RCTs, N = 1617, I2 = 89%). The evidence suggests that if the rate of live birth associated with conventional incubation and assessment is 48%, the rate with TLS utilising embryo selection software would be between 46% and 55%, and if the miscarriage rate with conventional incubation and assessment is 11%, the rate associated with TLS would be between 5% and 10%. No stillbirths occurred in the only study reporting this outcome.

AUTHORS' CONCLUSIONS

There is insufficient good-quality evidence of differences in live birth or ongoing pregnancy, miscarriage and stillbirth, or clinical pregnancy to choose between TLS, with or without embryo selection software, and conventional incubation. As the evidence is of low or very low-quality, our findings should be interpreted with caution.

Non-invasive embryo evaluation and selection using time-lapse monitoring: Results of a randomized controlled study

OBJECTIVE

Continuous monitoring of embryos via time-lapse (TL) provides more information on embryo kinetics and morphology compared to standard daily evaluation. Embryo selection by TL could support single embryo transfer (SET). With SET multiple gestations are avoided and perinatal outcome is improved. Our primary goal was to determine whether selection of a single blastocyst based on an algorithm comprising kinetic and morphologic scores assessed through continuous TL monitoring results in superior clinical outcome compared to embryo selection based on morphology alone. A secondary goal was to assess whether a time-lapse score based on kinetic and morphologic parameters was predictive of implantation.

STUDY DESIGN

Randomized controlled trial performed in two private IVF centers in Hungary. Infertile couples scheduled to undergo 1st or 2nd IVF cycles were enrolled. Female age had to be under 36 years. The intervention was embryo evaluation/selection based on TL algorithm. Patients were randomized to SET with TL monitoring (TL-eSET) vs. SET with standard evaluation (control-eSET). Assuming an increase in pregnancy from 44% to 58%, a sample size of 202 per group was calculated based on the interim analysis at 10% information fraction. The primary outcome of the study was pregnancy rate. Secondary outcomes were miscarriage rates, live birth, perinatal outcome and the ability of a time-lapse score constructed based on kinetic and morphologic parameters to predict implantation. Chi-square tests, likelihood-ratio tests and exact tests were used for the analysis of categorical variables. Continuous variables were compared using independent group t-test and analysis of variance.

RESULTS

The study was closed after three years. Eventually 161 patients were randomized and analyzed (N = 80 TL-eSET and N = 81 control-eSET). Pregnancy rate did not significantly differ between the groups though there was a trend favoring TL selection (TL-eSET: 46.3% vs control-eSET: 34.6%, p = 0.150; OR: 1.628 (95% CI: 0.857-3.092)). The time-lapse score based on morphologic and kinetic parameters was significantly higher for blastocysts that implanted vs. those that did not (14.5 ± 1.8 vs. 12.1 ± 2.9, p = 0.0001). There were no adverse effects of the intervention.

CONCLUSIONS

Selection of a single blastocyst based on information derived from time-lapse monitoring can aid embryo selection for SET.

Time-lapse systems for embryo incubation and assessment in assisted reproduction

BACKGROUND

Embryo incubation and assessment is a vital step in assisted reproductive technology (ART). Traditionally, embryo assessment has been achieved by removing embryos from a conventional incubator daily for quality assessment by an embryologist, under a light microscope. Over recent years time-lapse systems have been developed which can take digital images of embryos at frequent time intervals. This allows embryologists, with or without the assistance of embryo selection software, to assess the quality of the embryos without physically removing them from the incubator.The potential advantages of a time-lapse system (TLS) include the ability to maintain a stable culture environment, therefore limiting the exposure of embryos to changes in gas composition, temperature and movement. A TLS has the potential advantage of improving embryo selection for ART treatment by utilising additional information gained through continuously monitoring embryo development. Use of a TLS often adds significant extra cost onto an in vitro fertilisation (IVF) cycle.

OBJECTIVES

To determine the effect of a TLS compared to conventional embryo incubation and assessment on clinical outcomes in couples undergoing ART.

SEARCH METHODS

We used standard methodology recommended by Cochrane. We searched the Cochrane Gynaecology and Fertility (CGF) Group trials register, CENTRAL, MEDLINE, Embase, CINAHL and two trials registers on 2 August 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in the following comparisons: comparing a TLS, with or without embryo selection software, versus conventional incubation with morphological assessment; and TLS with embryo selection software versus TLS without embryo selection software among couples undergoing ART.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. The primary review outcomes were live birth, miscarriage and stillbirth. Secondary outcomes were clinical pregnancy and cumulative clinical pregnancy. We reported quality of the evidence for important outcomes using GRADE methodology. We made the following comparisons.TLS with conventional morphological assessment of still TLS images versus conventional incubation and assessmentTLS utilising embryo selection software versus TLS with conventional morphological assessment of still TLS images TLS utilising embryo selection software versus conventional incubation and assessment MAIN RESULTS: We included eight RCTs (N = 2303 women). The quality of the evidence ranged from very low to moderate. The main limitations were imprecision and risk of bias associated with lack of blinding of participants and researchers, and indirectness secondary to significant heterogeneity between interventions in some studies. There were no data on cumulative clinical pregnancy.TLS with conventional morphological assessment of still TLS images versus conventional incubation and assessmentThere is no evidence of a difference between the interventions in terms of live birth rates (odds ratio (OR) 0.73, 95% CI 0.47 to 1.13, 2 RCTs, N = 440, I2 = 11% , moderate-quality evidence) and may also be no evidence of difference in miscarriage rates (OR 2.25, 95% CI 0.84 to 6.02, 2 RCTs, N = 440, I2 = 44%, low-quality evidence). The evidence suggests that if the live birth rate associated with conventional incubation and assessment is 33%, the rate with use of TLS with conventional morphological assessment of still TLS images is between 19% and 36%; and that if the miscarriage rate with conventional incubation is 3%, the rate associated with conventional morphological assessment of still TLS images would be between 3% and 18%. There is no evidence of a difference between the interventions in the stillbirth rate (OR 1.00, 95% CI 0.13 to 7.49, 1 RCT, N = 76, low-quality evidence). There is no evidence of a difference between the interventions in clinical pregnancy rates (OR 0.88, 95% CI 0.58 to 1.33, 3 RCTs, N = 489, I2 = 0%, moderate-quality evidence).TLS utilising embryo selection software versus TLS with conventional morphological assessment of still TLS imagesNo data were available on live birth or stillbirth. We are uncertain whether TLS utilising embryo selection software influences miscarriage rates (OR 1.39, 95% CI 0.64 to 3.01, 2 RCTs, N = 463, I2 = 0%, very low-quality evidence) and there may be no difference in clinical pregnancy rates (OR 0.97, 95% CI 0.67 to 1.42, 2 RCTs, N = 463, I2 = 0%, low-quality evidence). The evidence suggests that if the miscarriage rate associated with assessment of still TLS images is 5%, the rate with embryo selection software would be between 3% and 14%.TLS utilising embryo selection software versus conventional incubation and assessmentThere is no evidence of a difference between TLS utilising embryo selection software and conventional incubation improving live birth rates (OR 1.21, 95% CI 0.96 to 1.54, 2 RCTs, N = 1017, I2 = 0%, very low-quality evidence). We are uncertain whether TLS influences miscarriage rates (OR 0.73, 95% CI 0.49 to 1.08, 3 RCTs, N = 1351, I2 = 0%, very low-quality evidence). The evidence suggests that if the live birth rate associated with no TLS is 38%, the rate with use of conventional incubation would be between 36% and 58%, and that if miscarriage rate with conventional incubation is 9%, the rate associated with TLS would be between 4% and 10%. No data on stillbirths were available. It was uncertain whether the intervention influenced clinical pregnancy rates (OR 1.17, 95% CI 0.94 to 1.45, 3 RCTs, N = 1351, I2 = 42%, very low-quality evidence).

AUTHORS' CONCLUSIONS

There is insufficient evidence of differences in live birth, miscarriage, stillbirth or clinical pregnancy to choose between TLS, with or without embryo selection software, and conventional incubation. The studies were at high risk of bias for randomisation and allocation concealment, the result should be interpreted with extreme caution.

Morphometric analysis of human oocytes using time lapse: does it predict embryo developmental outcomes?

The aim of this prospective study was to evaluate the relationship between morphometric parameters of metaphase II (MII) oocytes and the morphokinetic behaviour of subsequent embryos derived by intra-cytoplasmic sperm injection (ICSI). The association between oocyte morphometry: (whole oocyte), ooplasm, width of zona pellucida (ZP) and perivitelline space (PVS) and first polar body (PB) with embryo morphokinetic variables, including time of second PB extrusion (tPB2), pronuclei appearance (tPN), pronuclei fading (tPNf), formation of two to eight cells (t2 to t8) and irregular cleavage events [uneven at two cells stage, cell fusion (Fu) and trichomonas mitoses (TM)] were assessed. tPB2, t5 and t8 timings were related to the ooplasm diameter (p = 0.003, r = -0.12; p = 0.001, r = -0.16; p < 0.001 r = -0.36, respectively); otherwise, there were no significant relationships apart from an association between the oocyte morphometry and other morphokinetic parameters, irregular cleavage embryos as well as embryo arrest which approached significance (p > 0.05). Overall, the data showed that morphometric parameters of oocytes did not provide a tool for the prediction of embryo morphokinetic or embryo selection in ICSI cycles. However, ooplasm diameter might be useful as a marker for predicting the timing of embryo cleavage.

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.

Effect of oocyte vitrification on embryo quality: time-lapse analysis and morphokinetic evaluation

OBJECTIVE

To analyze whether oocyte vitrification may affect subsequent embryo development from a morphokinetic standpoint by means of time-lapse imaging.

DESIGN

Observational cohort study.

SETTING

University-affiliated private IVF center.

PATIENT(S)

Ovum donation cycles conducted with the use of vitrified (n = 631 cycles; n = 3,794 embryos) or fresh oocytes (n = 1,359 cycles; n = 9,935 embryos) over 2 years.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

Embryo development was analyzed in a time-lapse imaging incubator. The studied variables included time to 2 cells (t2), 3 cells (t3), 4 cells (t4), 5 cells (t5), morula (tM), and cavitated, early, and hatching blastocyst (tB, tEB, tHB) as well as 2nd cell cycle duration (cc2 = t3 - t2). All of the embryos were classified according to the hierarchic tree model currently used for embryo selection. The analyzed variables were compared with the use of analysis of variance or chi-square and included 95% confidence intervals (CIs).

RESULT(S)

The embryos that originated from vitrified oocytes showed a delay of ∼1 hour from the first division to 2 cells (t2) to the time of blastulation (tB). The embryos that originated from vitrified oocytes showed a delay of ∼1 hour from the 1st division to 2 cells (t2) to the time of blastulation (tB) (P<.05). The proportions of embryos allocated to categories A-E in the hierarchical tree were similar between groups. No differences in implantation rates between the fresh (51.3% [95% CI 47.1%-55.7%]) and vitrified (46.4% [95% CI 38.4%-54.4%]) groups were found.

CONCLUSION(S)

The embryo quality of vitrified oocytes was not impaired: cc2, quality according to our hierarchic morphokinetic model, and implantation rates were similar between fresh and vitrified oocytes. However, morphokinetic differences were observed from t2 to tB. Our main study limitation was the retrospective nature of the analysis, although a large database was studied.

Does time-lapse imaging have favorable results for embryo incubation and selection compared with conventional methods in clinical in vitro fertilization? A meta-analysis and systematic review of randomized controlled trials

OBJECTIVE

The present study aimed to undertake a review of available evidence assessing whether time-lapse imaging (TLI) has favorable outcomes for embryo incubation and selection compared with conventional methods in clinical in vitro fertilization (IVF).

METHODS

Using PubMed, EMBASE, Cochrane library and ClinicalTrial.gov up to February 2017 to search for randomized controlled trials (RCTs) comparing TLI versus conventional methods. Both studies randomized women and oocytes were included. For studies randomized women, the primary outcomes were live birth and ongoing pregnancy, the secondary outcomes were clinical pregnancy and miscarriage; for studies randomized oocytes, the primary outcome was blastocyst rate, the secondary outcome was good quality embryo on Day 2/3. Subgroup analysis was conducted based on different incubation and embryo selection between groups.

RESULTS

Ten RCTs were included, four randomized oocytes and six randomized women. For oocyte-based review, the pool-analysis observed no significant difference between TLI group and control group for blastocyst rate [relative risk (RR) 1.08, 95% CI 0.94-1.25, I2 = 0%, two studies, including 1154 embryos]. The quality of evidence was moderate for all outcomes in oocyte-based review. For woman-based review, only one study provided live birth rate (RR 1,23, 95% CI 1.06-1.44,I2 N/A, one study, including 842 women), the pooled result showed no significant difference in ongoing pregnancy rate (RR 1.04, 95% CI 0.80-1.36, I2 = 59%, four studies, including 1403 women) between two groups. The quality of the evidence was low or very low for all outcomes in woman-based review.

CONCLUSIONS

Currently there is insufficient evidence to support that TLI is superior to conventional methods for human embryo incubation and selection. In consideration of the limitations and flaws of included studies, more well designed RCTs are still in need to comprehensively evaluate the effectiveness of clinical TLI use.

Revealing the secret life of pre-implantation embryos by time-lapse monitoring: A review

High implantation success following in vitro fertilization cycles are achieved via the transfer of embryos with the highest developmental competence. Multiple pregnancies as a result of the transfer of several embryos per cycle accompany with various complication. Thus, single-embryo transfer (SET) is the preferred practice in assisted reproductive technique (ART) treatment. In order to improve the pregnancy rate for SET, embryologists need reliable biomarkers to aid their selection of embryos with the highest developmental potential. Time-lapse technology is a noninvasive alternative conventional microscopic assessment. It provides uninterrupted and continues the survey of embryo development to transfer day. Today, there are four time-lapse systems that are commercially available for ART centers. In world and Iran, the first time lapse babies were born in 2010 and 2015, respectively, conceived by SET. Here, we review the use of time-lapse monitoring in the observation of embryogenesis as well as its role in SET. Although, the findings from our review support common use of time-lapse monitoring in ART centers; but, future large studies assessing this system in well-designed trials are necessary.

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.

Time-lapse embryoscopy

Time-lapse (TL) embryo monitoring is the latest technology that is proposed for embryo evaluation and selection for transfer. TL technology enables us to collect significantly more information about the in vitro development of the embryos that can be obtained through the daily-once evaluation under the light microscope. In addition, the embryos do not need to be removed from the culture environment for this. The extra morphokinetic information and the undisturbed culture conditions could both be beneficial for the cultured embryo cohort. Many morphokinetic parameters have been tested in relation to variety of laboratory (e.g. blastocyst development) and clinical (implantation and live-birth rate) outcomes. Most of these studies are retrospective in nature and suffer from methodological problems (heterogeneous patient population, culture conditions not standardized, and small sample size). Several groups attempted to build algorithms, however, have not yet been confirmed externally as attempts so far could not reproduce the expected predictive abilities. Therefore, these algorithms cannot be universally accepted. The latest algorithm proposed for embryo selection was developed based on data from 24 clinics using local stimulation and laboratory procedures. It groups embryos into five categories (KIDScore) based on in and out of range kinetic events. The algorithm was tested in subsets of patients using various fertilization methods or culture conditions and its predictive ability remained the same. The authors, therefore, feel comfortable to recommend it for routine use in any laboratory using TL technology. There is, however, still limited prospective, randomized trial data testing the algorithms. This article reviews TL technology, retrospective and prospective reports on various morphokinetic parameters, and the benefits and shortcomings of currently available algorithms.

Do morphokinetic data sets inform pregnancy potential?

Purpose

The aim of this study was to create a model to predict the implantation of transferred embryos based on information contained in the morphokinetic parameters of time-lapse monitoring.

Methods

An analysis of time-lapse recordings of 410 embryos transferred in 343 cycles of in vitro fertilization (IVF) treatment was performed. The study was conducted between June 2012 and November 2014. For each embryo, the following data were collected: the duration of time from the intracytoplasmic sperm injection (ICSI) procedure to further division for two, three, four, and five blastomeres, time intervals between successive divisions, and the level of fragmentation assessed in successive time-points. Principal component analysis (PCA) and logistic regression were used to create a predictive model.

Results

Based on the results of principal component analysis and logistic regression analysis, a predictive equation was constructed. Statistically significant differences (p < 0.001) in the size of the created parameter between the implanted group (the median value: Me = −5.18 and quartiles: Q₁ = −5.61; Q₃ = −4.79) and the non-implanted group (Me = −5.69, Q₁ = −6.34; Q₃ = −5.16) were found. A receiver operating characteristic (ROC) curve constructed for the considered model showed the good quality of this predictive equation. The area under the ROC curve was AUC = 0.70 with a 95 % confidence interval (0.64, 0.75). The presented model has been validated on an independent data set, illustrating that the model is reliable and repeatable.

Conclusions

Morphokinetic parameters contain information useful in the process of creating pregnancy prediction models. However, embryo quality is not the only factor responsible for implantation, and, thus, the power of prediction of the considered model is not as high as in models for blastocyst formation. Nevertheless, as illustrated by the results of this study, the application of advanced data-mining methods in reproductive medicine allows one to create more accurate and useful models.

Can Comprehensive Chromosome Screening Technology Improve IVF/ICSI Outcomes? A Meta-Analysis

Objective

To examine whether comprehensive chromosome screening (CCS) for preimplantation genetic screening (PGS) has an effect on improving in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes compared to traditional morphological methods.

Methods

A literature search was conducted in PubMed, EMBASE, CNKI and ClinicalTrials.gov up to May 2015. Two reviewers independently evaluated titles and abstracts, extracted data and assessed quality. We included studies that compared the IVF/ICSI outcomes of CCS-based embryo selection with those of the traditional morphological method. Relative risk (RR) values with corresponding 95% confidence intervals (CIs) were calculated in RevMan 5.3, and subgroup analysis and Begg’s test were used to assess heterogeneity and potential publication bias, respectively.

Results

Four RCTs and seven cohort studies were included. A meta-analysis of the outcomes showed that compared to morphological criteria, euploid embryos identified by CCS were more likely to be successfully implanted (RCT RR 1.32, 95% CI 1.18–1.47; cohort study RR 1.74, 95% CI 1.35–2.24). CCS-based PGS was also related to an increased clinical pregnancy rate (RCT RR 1.26, 95% CI 0.83–1.93; cohort study RR 1.48, 95% CI 1.20–1.83), an increased ongoing pregnancy rate (RCT RR 1.31, 95% CI 0.64–2.66; cohort study RR 1.61, 95% CI 1.30–2.00), and an increased live birth rate (RCT RR 1.26, 95% CI 1.05–1.50; cohort study RR 1.35, 95% CI 0.85–2.13) as well as a decreased miscarriage rate (RCT RR 0.53, 95% CI 0.24–1.15; cohort study RR 0.31, 95% CI 0.21–0.46) and a decreased multiple pregnancy rate (RCT RR 0.02, 95% CI 0.00–0.26; cohort study RR 0.19, 95% CI 0.07–0.51). The results of the subgroup analysis also showed a significantly increased implantation rate in the CCS group.

Conclusions

The effectiveness of CCS-based PGS is comparable to that of traditional morphological methods, with better outcomes for women receiving IVF/ICSI technology. The transfer of both trophectoderm-biopsied and blastomere-biopsied CCS-euploid embryos can improve the implantation rate.