Trophectoderm morphology significantly affects the rates of ongoing pregnancy and miscarriage in frozen-thawed single-blastocyst transfer cycle in vitro fertilization

Diameter of Human Day Five Blastocysts and Birth Sex

Background This study aimed to evaluate the offspring sex ratio, born through fresh and cryo-thawed single blastocyst (BL) transfers regarding a single morphological, static parameter, namely, BL diameter. Methodology This retrospective, observational study was conducted at an assisted reproductive technology (ART) center, Kinderwunschzentrum Niederrhein Germany. We conducted a statistical analysis of all births resulting from fresh and thawed in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles after a single embryo transfer (SET). The main outcome measure was the offspring sex ratio after SET of a day five BL in relation to the BL diameter measurement. Results There were more female than male babies born in our study. We observed a tendency for BL to have a higher diameter, resulting in female offspring, which was not statistically relevant. We also compared the BL diameter in the fresh embryo transfer (ET) group with that of the cryo-thawed ET group, showing a tendency toward a larger diameter in the fresh ET group. In the ICSI cycles, there was a higher tendency for a larger BL diameter when compared to IVF cycles. In the fresh ET cycles, BL leading to the male sex at birth had a tendency toward a larger diameter than the female BL. In the cryo-thaw ET cycles, BL leading to the female sex had a tendency toward a larger diameter than the male BL. Conclusions Our results showed a tendency in the sex of offspring toward the female sex and no significant difference in the BL diameter of BL leading to birth after ART and consecutive transfer of day five BL.

Prioritized single vitrified blastocyst to be warmed between grades 3 or 4 blastocyst on day 5 transfer cycles

PURPOSE

Selecting the optimal blastocyst to implant during cryopreservation and warming is critial for in vitro fertilization success. Therefore, the aim of this study was to explore which blastocyst should be prioritized to be thawed when facing a single vitrified blastocyst on day 5 transfer.

METHODS

A retrospective study including 1,976 single vitrified-warmed blastocyst transfer cycles was conducted from January 2016 to December 2020.

RESULTS

We found that grade 4 vitrified blastocyst had a higher clinical pregnancy (60.64% vs. 49.48%, P < 0.001) and live birth rates (50.12% vs 39.59%, P < 0.001) than the grade 3 vitrified blastocyst. However, no statistical difference was found between groups in miscarriage rate, birth weight, or gestational age. Besides, the grade 4 vitrified-thawed blastocyst had significant potential to develop into grade 6 blastocyst after further culturing for 16 h (73.68% vs. 48.60%, P < 0.001). The grade 6 transferred blastocyst was markedly higher in both clinical pregnancy rate (61.88% vs. 51.53%, P < 0.001) and live birth rate (50.91% vs. 40.46%, P < 0.001) compared to grade 5 transferred blastocyst.

CONCLUSIONS

Grade 4 vitrified blastocyst is recommended when facing single vitrified blastocyst on day 5 transfer. More importantly, the "embryonic escape hypothesis" was firstly proposed to reveal the findings.

When the Embryo Meets the Endometrium: Identifying the Features Required for Successful Embryo Implantation

Evaluation of the optimal number of embryos, their quality, and the precise timing for transfer are critical determinants in reproductive success, although still remaining one of the main challenges in assisted reproduction technologies (ART). Indeed, the success of in vitro fertilization (IVF) treatments relies on a multitude of events and factors involving both the endometrium and the embryo. Despite concerted efforts on both fronts, the overall success rates of IVF techniques continue to range between 25% and 30%. The role of the endometrium in implantation has been recently recognized, leading to the hypothesis that both the "soil" and the "seed" play a central role in a successful pregnancy. In this respect, identification of the molecular signature of endometrial receptivity together with the selection of the best embryo for transfer become crucial in ART. Currently, efforts have been made to develop accurate, predictive, and personalized tests to identify the window of implantation and the best quality embryo. However, the value of these tests is still debated, as conflicting results are reported in the literature. The purpose of this review is to summarize and critically report the available criteria to optimize the success of embryo transfer and to better understand current limitations and potential areas for improvement.

Beyond appearance: Can morphologically low-grade euploid blastocysts yield successful pregnancies?

Purpose

The primary objective of this investigation is to evaluate how morphological quality affects the pregnancy outcomes in euploid embryos determined by preimplantation genetic testing for aneuploidies (PGT-A). Concurrently, as a secondary objective, we aim to identify which specific aspects of morphological evaluation exert the most significant impact on these outcomes.

Methods

A retrospective analysis of 451 single euploid embryo transfer cycles at our clinic was conducted. Embryos were evaluated based on the degree of blastocyst expansion, inner cell mass (ICM), trophectoderm (TE) morphology, and the day of blastocyst vitrification. Outcomes between morphologically low-grade and high-grade embryos were compared. Additionally, the study analyzed which morphological factors most influenced pregnancy outcomes.

Results

Pregnancy outcomes were significantly lower in morphologically low-grade blastocysts compared to high-grade ones. Among the morphological evaluations, the ICM assessment was significantly associated with the live birth rate.

Conclusion

Our study indicates that the morphological quality of euploid embryos, particularly the evaluation of the ICM, plays a crucial role in IVF-ET success.

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

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

Polycystic ovary syndrome increases the rate of early spontaneous miscarriage in women who have undergone single vitrified euploid blastocyst transfer

RESEARCH QUESTION

Does polycystic ovary syndrome (PCOS) independently influence the risk of early spontaneous miscarriage in patients undergoing single euploid vitrified blastocyst transfer?

DESIGN

This observational cohort study retrospectively analysed 1498 patients undergoing their first single euploid blastocyst frozen transfer cycles between October 2016 and December 2021. Patients were divided into PCOS and non-PCOS groups according to the Rotterdam criteria. Logistic regression analysis was conducted to study the independent effect of maternal PCOS status on early spontaneous miscarriage after single euploid embryo transfer after adjusting for confounding factors.

RESULTS

No statistically significant differences were identified in the rates of positive pregnancy test (68.95% versus 64.86%, P = 0.196) or clinical pregnancy (59.93% versus 57.33%, P = 0.429) between the PCOS and non-PCOS groups after single euploid embryo transfer. Early spontaneous miscarriage occurred more frequently in women with PCOS compared with controls (18.67% versus 12.00%, P = 0.023). In single euploid embryo transfer cycles, PCOS significantly increased the incidence of early spontaneous miscarriage after adjusting for some potential confounders (adjusted odds ratio 1.649, 95% CI 1.032 to 2.635, P = 0.036).

CONCLUSIONS

Although no significant difference was observed in clinical pregnancy rates, PCOS status increased the risk of early spontaneous miscarriage after single vitrified euploid blastocyst transfer, suggesting an additional role of endometrial dysfunction affected by endocrine disorders. Further studies are needed to investigate the specific mechanisms and effective intervention strategies.

Towards Automation in IVF: Pre-Clinical Validation of a Deep Learning-Based Embryo Grading System during PGT-A Cycles

Preimplantation genetic testing for aneuploidies (PGT-A) is arguably the most effective embryo selection strategy. Nevertheless, it requires greater workload, costs, and expertise. Therefore, a quest towards user-friendly, non-invasive strategies is ongoing. Although insufficient to replace PGT-A, embryo morphological evaluation is significantly associated with embryonic competence, but scarcely reproducible. Recently, artificial intelligence-powered analyses have been proposed to objectify and automate image evaluations. iDAScore v1.0 is a deep-learning model based on a 3D convolutional neural network trained on time-lapse videos from implanted and non-implanted blastocysts. It is a decision support system for ranking blastocysts without manual input. This retrospective, pre-clinical, external validation included 3604 blastocysts and 808 euploid transfers from 1232 cycles. All blastocysts were retrospectively assessed through the iDAScore v1.0; therefore, it did not influence embryologists' decision-making process. iDAScore v1.0 was significantly associated with embryo morphology and competence, although AUCs for euploidy and live-birth prediction were 0.60 and 0.66, respectively, which is rather comparable to embryologists' performance. Nevertheless, iDAScore v1.0 is objective and reproducible, while embryologists' evaluations are not. In a retrospective simulation, iDAScore v1.0 would have ranked euploid blastocysts as top quality in 63% of cases with one or more euploid and aneuploid blastocysts, and it would have questioned embryologists' ranking in 48% of cases with two or more euploid blastocysts and one or more live birth. Therefore, iDAScore v1.0 may objectify embryologists' evaluations, but randomized controlled trials are required to assess its clinical value.

Morphology of inner cell mass: a better predictive biomarker of blastocyst viability

Background

Transfer of embryos at the blastocyst stage is one of the best approaches for achieving a higher success rate in In vitro fertilization (IVF) treatment as it demonstrates an improved uterine and embryonic synchrony at implantation. Despite novel biochemical and genetic markers proposed for the prediction of embryo viability in recent years, the conventional morphological grading of blastocysts remains the classical way of selection in routine practice. This study aims to investigate the association between the morphological features of blastocysts and pregnancy outcomes.

Methods

This prospective study included women undergoing single or double frozen blastocyst transfers following their autologous cycles in a period between October 2020 and September 2021. The morphological grades (A-good, B-average, and C-poor) of inner cell mass (ICM) and trophectoderm (TE) of blastocysts with known implantation were compared to assess their predictive potential of pregnancy outcome. It was further explored by measuring the relationship between the two variables using logistic regression and receiver operating characteristic (ROC) analysis.

Results

A total of 1,972 women underwent frozen embryo transfer (FET) cycles with a total of 3,786 blastocysts. Known implantation data (KID) from 2,060 blastocysts of 1,153 patients were subjected to statistical analysis, the rest were excluded. Implantation rates (IR) from transfer of ICM/TE grades AA, AB, BA, BB were observed as 48.5%, 39.4%, 23.4% and 25% respectively. There was a significantly higher IR observed in blastocysts with ICM grade A (p < 0.001) than those with B irrespective of their TE scores. The analysis of the interaction between the two characteristics confirmed the superiority of ICM over TE as a predictor of the outcome. The rank biserial correlation value for ICM was also greater compared to that of TE (0.11 vs 0.05).

Conclusion

This study confirms that the morphology of ICM of the blastocyst is a stronger predictor of implantation and clinical pregnancy than that of TE and can be utilized as a biomarker of viability.

Correlation between an annotation-free embryo scoring system based on deep learning and live birth/neonatal outcomes after single vitrified-warmed blastocyst transfer: a single-centre, large-cohort retrospective study

Propose

Does an annotation-free embryo scoring system based on deep learning and time-lapse sequence images correlate with live birth (LB) and neonatal outcomes?

Methods

Patients who underwent SVBT cycles (3010 cycles, mean age: 39.3 ± 4.0). Scores were calculated using the iDAScore software module in the Vitrolife Technology Hub (Vitrolife, Gothenburg, Sweden). The correlation between iDAScore, LB rates, and total miscarriage (TM), including 1st- and 2nd-trimester miscarriage, was analysed using a trend test and multivariable logistic regression analysis. Furthermore, the correlation between the iDAScore and neonatal outcomes was analysed.

Results

LB rates decreased as iDAScore decreased (P < 0.05), and a similar inverse trend was observed for the TM rates. Additionally, multivariate logistic regression analysis showed that iDAScore significantly correlated with increased LB (adjusted odds ratio: 1.811, 95% CI: 1.666–1.976, P < 0.05) and decreased TM (adjusted odds ratio: 0.799, 95% CI: 0.706–0.905, P < 0.05). There was no significant correlation between iDAScore and neonatal outcomes, including congenital malformations, sex, gestational age, and birth weight. Multivariate logistic regression analysis, which included maternal and paternal age, maternal body mass index, parity, smoking, and presence or absence of caesarean section as confounding factors, revealed no significant difference in any neonatal characteristics.

Conclusion

Automatic embryo scoring using iDAScore correlates with decreased miscarriage and increased LB and has no correlation with neonatal outcomes.

Supplementary information

The online version contains supplementary material available at 10.1007/s10815-022-02562-5.

Investigating of the effects of trophectoderm morphology on obstetrics outcome in 5th day blastocyst transfer in patients with in vitro fertilization

Objective:

Trophectoderm (TE) cells are the first differentiating cells in embryo development and have epithelial features. TE cells, which associate with implantation of the blastocyst into the uterine endometrium, contribute to the formation of the placenta. Inner cells mass (ICM) together with TE cells are used for determining embryo quality. The aim of this study was to investigate the role of TE and ICM cells on pregnancy outcome in 5^th day blastocyst transferred in-vitro-fertilization (IVF) pregnancy.

Material and Methods:

This was a retrospective study using data from all patients who applied for blastocyst transfer IVF between January 2015 and March 2019 at the Reproductive Endocrinology and Infertility Center of Akdeniz University Faculty of Medicine, Department of Obstetrics and Gynecology. ALPHA İstanbul consensus evaluation system was used for grading of the blastocyst. The embryo quality, expansion, ICM and TE morphology of the 5^th day transferred blastocyst was assessed, together with abortion rate, live birth rate, pregnancy complications, and pregnancy outcomes.

Results:

There was a significantly increased risk of preeclampsia (PE) (7.8% vs 1.1%; p=0.041), preterm delivery (PD) (36% vs 17.7%; p=0.037), and antenatal bleeding rates (13.6% vs 5%; p=0.021) in TE-C compared to the TE-A + TE-B blastocysts. Furthermore, a higher rate of obstetric complications was observed in ICM-C compared to ICM-A and B (p=0.003). There was a significant correlation between TE morphology and implantation success, ongoing pregnancy rate, and abortion incidence.

Conclusion:

These results suggest that TE cell morphology is related to implantation success and pregnancy outcomes, especially in terms of the risk of abortion, PE, PD, and antenatal bleeding. It may be advisable to counsel women concerning possible poor obstetric outcome due to poor ICM quality. Future prospective and controlled studies are needed to clarify this association.

Stem Cell-Based Trophoblast Models to Unravel the Genetic Causes of Human Miscarriages

Miscarriage affects approximately 15% of clinically recognized pregnancies, and 1-3% of couples experience pregnancy loss recurrently. Approximately 50-60% of miscarriages result from chromosomal abnormalities, whereas up to 60% of euploid recurrent abortions harbor variants in candidate genes. The growing number of detected genetic variants requires an investigation into their role in adverse pregnancy outcomes. Since placental defects are the main cause of first-trimester miscarriages, the purpose of this review is to provide a survey of state-of-the-art human in vitro trophoblast models that can be used for the functional assessment of specific abnormalities/variants implicated in pregnancy loss. Since 2018, when primary human trophoblast stem cells were first derived, there has been rapid growth in models of trophoblast lineage. It has been found that a proper balance between self-renewal and differentiation in trophoblast progenitors is crucial for the maintenance of pregnancy. Different responses to aneuploidy have been shown in human embryonic and extra-embryonic lineages. Stem cell-based models provide a powerful tool to explore the effect of a specific aneuploidy/variant on the fetus through placental development, which is important, from a clinical point of view, for deciding on the suitability of embryos for transfer after preimplantation genetic testing for aneuploidy.

The impact of euploid blastocyst morphology and maternal age on pregnancy and neonatal outcomes in natural cycle frozen embryo transfers

PURPOSE

To evaluate whether morphology impacts the pregnancy and neonatal outcomes of euploid blastocysts, and whether maternal age still affects outcomes when top-graded, euploid blastocysts are used.

METHODS

This retrospective cohort study included all natural-cycle frozen embryo transfers (NC-FET) using an autologous, euploid blastocyst from June 2016 to June 2020 (n = 610). There were five groups based on embryo grade: AA, AB, BA, BB, and "any C". For analysis of only AA-graded embryos, there were three maternal age groups: < 35, 35-39, and 40 + years. The main outcomes measured were clinical pregnancy and live birth rates, while the secondary outcomes included neonatal outcomes such as gestational age at delivery and birthweight. Multivariable logistic regression models were performed to adjust for confounders.

RESULTS

Euploid blastocysts with poorer morphology had lower odds of pregnancy and live birth; specifically, embryos with inner cell mass (ICM) graded as "C" had statistically significant decreased odds of pregnancy (aOR 0.33, p = 0.04) and live birth (aOR 0.32, p = 0.03) compared with ICM grade "A". The differences in pregnancy rate between trophectoderm grades were not statistically significant. Even in cycles that transferred a top-graded (AA) euploid embryo, maternal age at transfer was independently associated with outcomes. Embryo grade and maternal age, however, did not significantly impact neonatal outcomes such as prematurity and birthweight.

CONCLUSION

The morphology of euploid blastocysts and maternal age at NC-FET both independently impact pregnancy outcomes. Neonatal outcomes were similar across embryo morphology and maternal age groups, suggesting that lower morphology euploid embryos not be discounted as viable options for transfer.

Effect of Blastocyst Morphology and Developmental Rate on Euploidy and Live Birth Rates in Preimplantation Genetic Testing for Aneuploidy Cycles With Single-Embryo Transfer

OBJECTIVE

The aim of this study was to investigate whether blastocyst morphology and developmental rate are associated with euploidy and live birth rates (LBRs) in single euploid frozen-thawed embryo transfer (FET) cycles.

DESIGN

Retrospective cohort study.

METHODS

This study included 431 preimplantation genetic testing for aneuploidy (PGT-A) cycles followed by 393 FET cycles performed at our center from June 2017 to March 2021. All cycles were analyzed for euploidy based on blastocyst morphology (good, average and poor), developmental stage (day 5 and 6) and maternal age (< 35 and ≥ 35 years old). Multivariate logistic analysis models were used to identify the independent effects of conventional blastocyst morphology, developmental rate and morphological parameters (degree of blastocoele expansion, and grade of inner cell mass and trophectoderm (TE)) on LBRs.

RESULTS

In the group of women aged < 35 years, compared with poor-quality blastocysts, good-quality blastocysts (62.90% vs. 32.46%; odds ratio (OR) 3.163, 95% confidence interval (CI) 2.247-4.451; P < 0.001) and average-quality blastocysts (46.70% vs. 32.46%; OR 1.665, 95% CI 1.287-2.154; P < 0.001) had significantly higher euploidy rates. Additionally, day 5 blastocysts were associated with higher euploidy rates than day 6 blastocysts (49.28% vs. 35.02%; OR 1.506, 95% CI 1.191-1.903; P= 0.001). In the group of women aged ≥ 35 years, euploidy rates were also associated with blastocyst morphology, with 41.86%, 45.65% and 24.39% of good, average and poor-quality embryos, respectively, exhibiting euploidy. However, no relationship was seen between euploidy and blastocyst developmental rate. Multiple logistic regression analysis show that overall blastocyst morphology of euploid embryos was not associated with LBR, only embryos with A-grade TE had significantly higher LBRs than those with C-grade TE (62.71% vs. 45.40%; OR 2.189, 95% CI 1.166-4.109; P=0.015). Similarly, LBRs were significantly higher when day 5 blastocysts were transferred than when day 6 blastocysts were transferred (57.75% vs. 41.67%; OR 2.132, 95% CI 1.370-3.318; P = 0.001).

CONCLUSION

Poor-quality embryos have reduced rates of euploidy. However, blastocyst developmental rate only significantly associates with euploidy rates in women aged younger than 35. Furthermore, only TE grade and blastocyst developmental rate are significantly associated with LBRs following FET cycles.

Trophectoderm Biopsy Differentially Influences the Level of Serum β-Human Chorionic Gonadotropin With Different Embryonic Trophectoderm Scores in Early Pregnancy From 7847 Single-Blastocyst Transfer Cycles

OBJECTIVE

To evaluate whether trophectoderm (TE) biopsy differentially influence the level of serum β-human chorionic gonadotropin (β-hCG) with different TE-scored blastocysts transferred in early pregnancy.

METHODS

This retrospective cohort study contained 7847 single-blastocyst transfer cycles executed between January 2019 and June 2020, including 2657 preimplantation genetic testing (PGT) cycles and 5190 in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles. All cycles were classified into biopsy and control groups, and further stratified based on the TE morphological scores into three subgroups: grades A, B, and C for TE scores, respectively. Intra-group and inter-group analyses were performed on serum β-hCG levels on the 12th day after blastocyst transfer (HCG₁₂), and obstetric and neonatal outcomes.

RESULTS

For cycles with a live birth, in grade A TE score subgroups, the HCG₁₂ level did not exhibit statistical significance between the control and biopsy groups after adjustment (769 mIU/mL vs. 753 mIU/mL, P=0.631). In contrast, in grade B and C TE score subgroups, the control group showed a significantly higher level of HCG₁₂ relative to the biopsy group (690 mIU/mL vs. 649 mIU/mL, P=0.001; 586 mIU/mL vs. 509 mIU/mL, P<0.001, respectively). We observed no statistically significant differences in obvious adverse obstetric and neonatal outcomes between the same TE-score subgroups of the biopsy group and control group.

CONCLUSIONS

While blastocysts with higher TE grades produced higher serum β-hCG levels in early pregnancy, TE biopsy might exert a negative impact on serum β-hCG levels by blastocysts with a grade-B TE score and below. TE biopsy did not increase the risk for adverse obstetric and neonatal outcomes.

Developmental stage and morphology of the competent blastocyst are associated with sex of the child but not with other obstetric outcomes: a multicenter cohort study

STUDY QUESTION

Are transfer day, developmental stage and morphology of the competent blastocyst in pregnancies leading to live birth associated with preterm birth, birthweight, length at birth and sex of the child?

SUMMARY ANSWER

A high score in blastocyst developmental stage and in trophectoderm (TE) showed a significant association with the sex of the child, while no other associations with obstetric outcomes were observed.

WHAT IS KNOWN ALREADY

The association between blastocyst assessment scores and obstetric outcomes have been reported in small single-center studies and the results are conflicting.

STUDY DESIGN, SIZE, DURATION

Multicenter historical cohort study based on exposure data (transfer day (blastocyst developmental stage reached by Day 5 or Day 6)) blastocyst developmental stage (1-6) and morphology (TE and inner cell mass (ICM): A, B, C)) and outcome data (preterm birth, birthweight, length at birth, and sex of the child) from women undergoing single blastocyst transfer resulting in a singleton pregnancy and live birth.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data from 16 private and university-based facilities for clinical services and research were used. A total of 7246 women, who in 2014-2018 underwent fresh-embryo transfer with a single blastocyst or frozen-thawed embryo transfer (FET) with a single blastocyst resulting in a singleton pregnancy were identified. Linking to the Danish Medical Birth Registry resulted in a total of 4842 women with a live birth being included. Cycles with pre-implantation genetic testing and donated gametes were excluded. The analyses were adjusted for female age (n = 4842), female BMI (n = 4302), female smoking (n = 4290), parity (n = 4365), infertility diagnosis (n = 4765), type of treatment (n = 4842) and center (n = 4842); some analyses additionally included gestational age (n = 4368) and sex of the child (n = 4833).

MAIN RESULTS AND THE ROLE OF CHANCE

No statistically significant associations between blastocyst assessment scores (transfer day, developmental stage, TE, ICM) and preterm birth (8.3%) or birthweight (mean 3461.7 g) were found. The adjusted association between blastocysts with a TE score of C and a TE score of A and length at birth (mean 51.6 cm) were statistically significant (adjusted mean difference 0.4 cm (95% CI: 0.02; 0.77)). Blastocysts transferred with developmental stage score 5 compared to blastocysts transferred with score 3 had a 34% increased probability of being a boy (odds ratio (OR) 1.34 (95% CI: 1.09; 1.64). Further, TE score B blastocysts compared to TE score A blastocysts had a 31% reduced probability of being a boy (OR 0.69 (95% CI: 0.60; 0.80)).

LIMITATIONS, REASONS FOR CAUTION

It is possible that some residual confounding remains.

WIDER IMPLICATIONS OF THE FINDINGS

Blastocyst selection during ART does not appear to introduce any negative effects on obstetric outcome. Therefore, clinicians and patients can be reassured that the assessment scores of the selected blastocyst will not in themselves pose a risk of preterm birth or affect birthweight and the length at birth.

STUDY FUNDING/COMPETING INTEREST(S)

Unrestricted grant from Gedeon Richter Nordics AB, Sweden. None of the authors have any competing interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Advanced trophectoderm quality increases the risk of a large for gestational age baby in single frozen-thawed blastocyst transfer cycles

STUDY QUESTION

Does trophectoderm (TE) quality affect birthweight after single frozen-thawed blastocyst transfer?

SUMMARY ANSWER

Transfer of single blastocyst with advanced TE quality was associated with higher birthweight and increased risk of a large for gestational age (LGA) baby.

WHAT IS KNOWN ALREADY

Transfer of blastocysts with advanced TE quality results in higher ongoing pregnancy rates and a lower miscarriage risk. However, data on the relationship between TE quality and birthweight are still lacking.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study at a tertiary-care academic medical center included 1548 singleton babies born from single frozen-thawed blastocyst transfer from January 2011 to June 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Babies were grouped into four groups according to embryo expansion (Stages 3, 4, 5 and 6), three groups according to inner cell mass (ICM) quality (A, B and C), and three groups according to TE quality (A, B and C). Main outcomes included absolute birthweight, Z-scores adjusted for gestational age and gender, and adverse neonatal outcomes. Multivariable linear and logistic regression analyses were performed to investigate the association of neonatal outcomes with expansion stage, ICM quality and TE quality.

MAIN RESULTS AND THE ROLE OF CHANCE

As TE quality decreased, birthweight (3468.10 ± 471.52, 3357.69 ± 522.06, and 3288.79 ± 501.90 for A, B and C, respectively, P = 0.002), Z-scores (0.59 ± 1.07, 0.42 ± 1.04, and 0.27 ± 1.06 for A, B and C, respectively, P = 0.002) and incidence of LGA (28.9%, 19.7% and 17.4% for A, B and C, respectively, P = 0.027) decreased correspondingly. After adjusting for confounders, compared with the Grade A group, blastocysts with TE Grade B (standardized coefficients (β): -127.97 g, 95% CI: -234.46 to -21.47, P = 0.019) and blastocysts with TE grade C (β: -200.27 g, 95% CI: -320.69 to -79.86, P = 0.001) resulted in offspring with lower birthweight. Blastocysts with TE grade C brought babies with lower Z-scores than TE Grade A (β: -0.35, 95% CI: -0.59 to -0.10, P = 0.005). Also, embryos with TE Grade B (adjusted odds ratio (aOR):0.91, 95% CI: 0.84 to 0.99, P = 0.033) and embryos with TE Grade C (aOR : 0.89, 95% CI: 0.81 to 0.98, P = 0.016) had lower chance of leading to a LGA baby than those with TE Grade A. No association between neonatal outcomes with embryo expansion stage and ICM was observed (all P > 0.05).

LIMITATIONS, REASONS FOR CAUTION

The retrospective design, lack of controlling for several unknown confounders, and inter-observer variation limited this study.

WIDER IMPLICATIONS OF THE FINDINGS

The study extends our knowledge of the down-stream effect of TE quality on newborn birthweight and the risk of LGA.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by National Key R&D Program of China (2018YFC1003000), National Natural Science Foundation of China (81771533 to Y.P.K. and 31200825 to L.S.) and Innovative Research Team of High-level Local Universities in Shanghai (SSMU-ZLCX20180401), Shanghai Sailing Program(21YF1423200) and the Fundamental research program funding of Ninth People's Hospital affiliated to Shanghai Jiao Tong university School of Medicine (JYZZ117). The authors declare no conflict of interest in this present study.

TRIAL REGISTRATION NUMBER

N/A.

Effect of Age and Embryo Morphology on Live Birth Rate After Transfer of Unbiopsied Blastocysts

OBJECTIVE

To determine the rate of live birth per blastocyst based on morphology and oocyte age using data from a single center.

METHODS

This is a mathematical analysis and model building study of autologous blastocyst stage embryo transfers at a University-affiliated center. A total of 448 blastocyst stage embryos were transferred in 244 fresh and frozen embryo transfers from May 2015 through April 2018. Blastocyst morphology was divided into good, fair, and poor overall morphology grades. Each embryo transfer was modeled as an equation equating the sum of the unknown live birth rates of the transferred embryos to the number of live births that resulted. The least squares solution to the system of embryo transfer equations was determined using linear algebra.

RESULTS

Trophectoderm morphology was a better predictor of live birth rate than inner cell mass morphology. Embryos graded AA/AB/BA (good) had the highest live birth rates followed by BB/CB (fair), and BC/CC (poor). In our youngest age group (25-32 years) live birth rates per embryo were 51% for good, 39% for fair, and 25% for poor quality embryos. In our oldest age group (40-44 years) the live birth rates per embryo were 22% for good, 14% for fair, and 8% for poor quality embryos.

CONCLUSIONS

These techniques can help analyze small datasets such as those from individual clinics to aid in determining the ideal number of embryos to transfer to achieve live birth while limiting the risk of multiple gestations.

Effect of age and morphology on sustained implantation rate after euploid blastocyst transfer

RESEARCH QUESTION

What impact does maternal age and embryo morphology have on sustained implantation rates of euploid blastocysts?

DESIGN

This was a retrospective analysis of sustained implantation rates of euploid blastocysts stratified by maternal age and morphology. The primary analysis included 208 embryo transfers with a total of 229 embryos transferred from January 2017 through August 2020.

RESULTS

For all ages the sustained implantation rates for day 5 good quality blastocysts were higher than for day 5 fair, day 5 poor and day 6 blastocysts. At a maternal age of 36 years the best-fit sustained implantation rates were 86% for day 5 good quality blastocysts, 64% for day 5 fair, 63% for day 5 poor, and 51% for all day 6 blastocysts analysed as one group. When controlling for morphology and day of biopsy, there were higher sustained implantation rates for euploid embryos of younger patients compared with older patients. The best-fit sustained implantation rates for age 33 compared to age 39 years were 86% versus 80% for day 5 good, 71% versus 62% for day 5 fair, 59% versus 55% for day 5 poor, and 81% versus 46% for all day 6.

CONCLUSIONS

There was a clinically significant higher sustained implantation rate at all ages for euploid day 5 good quality embryos compared with day 5 fair, day 5 poor and day 6 embryos.

Euploidy rates are not affected when embryos are cultured in a continuous (CCM) or sequential culture medium (SCM): a sibling oocyte study

PURPOSE

To determine if euploidy rates and embryo development differ when blastocysts are cultured in CCM or SCM.

METHOD

A single-center retrospective observational study was performed from September 2018 to March 2019. Patients [23-46 years] with at least four fresh mature oocytes (MII) without severe male factor infertility were included. Sibling MII were injected and cultured in Global®Total®LP (CCM) or Sage Quinn's Advantage® Cleavage and Blastocyst media (SCM) under 6% CO₂, 5% O₂, and 89% N₂. Fertilization, cleavage, day (D) 5 blastulation, usable blastocyst (blastocysts biopsied/normally fertilized oocytes), and euploidy rates were recorded. Blastocysts were graded prior to trophectoderm (TE) biopsy on D5, 6, or 7 for genetic testing and mitochondrial DNA (mtDNA) quantification.

RESULTS

According to clinical practice, 1452 MII were randomly distributed: 751 in CCM and 701 in SCM. No differences were observed in fertilization and cleavages rates for CCM and SCM (77.4% vs 75.5%, p = 0.429 and 97.6% vs 99.1%, p = 0.094, respectively). Blastulation rate on D5 was higher in CCM (70.6% vs 62.2, p = 0.009); however, usable blastocyst rates were comparable (CCM: 58.3% vs SCM: 56.7%, p = 0.625). From a Poisson regression model adjusted for confounding factors, euploidy rates were not different between media (aOR = 1.18, [0.94-1.48], p = 0.157). Euploid blastocyst's mtDNA values were similar (CCM: 32.2, [30.5, 34.1] and SCM: 33.5, [31.8, 35.2], p = 0.345) and top-quality blastocysts (AA/BA) were increased in SCM (OR=1.04, [1.00-1.09], p = 0.037).

CONCLUSION

Under controlled in vitro conditions, euploidy rates and embryo development are comparable when embryos are cultured in CCM or SCM.

Which factors affect the likelihood of miscarriage after single euploid blastocyst transfer?

RESEARCH QUESTION

Which parameters affect the likelihood of miscarriage after single euploid frozen-thawed blastocyst transfer (FBT)?

DESIGN

In this retrospective study, clinical and laboratory data from 1051 single euploid FBTs were evaluated. Exclusion criteria were endocrine or systemic pathologies, uterine anomalies or pathologies, unilateral or bilateral hydrosalpinx, karyotypic abnormalities (either maternal or paternal) or thrombophilia. Patients were divided into two groups according to pregnancy outcome: live birth and miscarriage.

RESULTS

Body mass index (BMI) (25.98 ± 0.5 versus 24.36 ± 0.21, P = 0.019), duration of infertility (6.62 ± 0.54 versus 4.92 ± 0.18, P = 0.006) and number of previous miscarriages (1.36 ± 0.13 versus 0.79 ± 0.05, P < 0.001) were significantly higher in the miscarriage group (n = 100) than in the live birth group (n = 589). Although the trophectoderm and inner cell mass (ICM) percentage scores were not statistically different among the miscarriage and live birth groups, the percentage of day-6 biopsied embryos was significantly higher in the miscarriage group. Binary logistic regression analysis revealed that BMI (OR 1.083, 95% CI 1.013 to 1.158, P = 0.02) and number of previous miscarriages (OR 1.279, 95% CI 1.013 to 1.158, P = 0.038) were independent factors for miscarriage. Patients with elevated BMI and a higher number of miscarriages were at increased risk of miscarriage.

CONCLUSION

After a single euploid FBT, BMI and number of previous miscarriages are predictors of miscarriage. Lifestyle interventions before FBT may decrease miscarriage rates.

Prediction of embryo survival and live birth rates after cryotransfers of vitrified blastocysts

RESEARCH QUESTION

Which pre-vitrification parameters are the most predictive of survival and live birth in vitrified-warmed blastocyst transfer cycles?

DESIGN

A retrospective study including 11,936 warmed blastocysts. Pre-vitrification morphological parameters analysed for blastocysts included day of vitrification; blastocyst expansion degree; trophoectoderm grade (A, B and C); and inner cell mass grade (A, B and C). Univariate and multivariate generalized estimating equations models were used to analyse survival, clinical pregnancy and live birth rate. A stepwise regression analysis was conducted to select and classify by order which outcomes were the most predictive.

RESULTS

The odds of survival increased almost twice for blastocysts with lower expansion degree (OR 1.92; 95% CI 1.37 to 2.69; P < 0.001) and by about 50% for blastocysts vitrified on day 5 (OR 1.56; 95% CI 1.27 to 1.89; P < 0.001). Multivariate generalized estimating equations model showed that trophectoderm grade followed by the day of vitrification were the most significant predictors of live birth. The odds of live birth increased nearly three times for blastocysts with trophectoderm graded as A compared with those with trophectoderm graded as C (OR 2.85; 95% CI 2.48 to 3.27; P < 0.001), and double for blastocysts vitrified on day 5 compared with those vitrified on day 6 (OR 2.22; 95% CI 1.97 to 2.49; P < 0.001). The odds of live birth also increased in higher expansion degree blastocysts.

CONCLUSIONS

Blastocysts vitrified on day 5 and those with higher trophoectoderm grade should be given priority when warming.

The Morphology of Inner Cell Mass Is the Strongest Predictor of Live Birth After a Frozen-Thawed Single Embryo Transfer

Background

The scoring system for human blastocysts is traditionally based on morphology; however, there are controversies on the effect of morphology parameters on pregnancy outcomes. The aim of this study is to evaluate the predicting value of each morphology parameter on pregnancy outcomes in a setting of single embryo transfer.

Methods

This is a retrospective cohort study on patients undergoing frozen-thawed single blastocyst transfer at our center, between Jan. 2009 and Dec. 2018. A total of 10,482 cycles were analyzed. The blastocysts were scored according to the expansion and hatching status, morphology of inner cell mass (ICM), and cells of trophectoderm (TE). The primary outcome measure was live birth rate. One-way analysis of variance, chi-square test, and multiple logistic regression were used for statistical analysis.

Results

The clinical pregnancy rate was lower in the blastocysts of stage 3 (48.15%), compared with those of stage 4 (56.15%), stage 5 (54.91%), and stage 6 (53.37%). The live birth rate was lower in the blastocysts of stage 3 (37.07%), compared with those of stage 4 (44.21%) and stage 5 (41.67%). The rates of clinical pregnancy (A: 66.60%, B: 53.25%, C: 39.33%) and live birth (A: 54.62%, B: 41.29%, C: 28.45%) were both decreased with decreasing grade of ICM morphology, and these differences were pairwise significant. The miscarriage rate of blastocysts with ICM grade A was lower, compared with ICM grade C (17.53 vs. 27.66%). Blastocysts with TE morphology of C had lower rates of clinical pregnancy (43.53%) and live birth (32.57%), compared with those with TE morphology of A and B (clinical pregnancy rate: 64.26% for A, 58.11% for B; live birth rate: 52.74% for A, 45.64% for B). There were no significant differences in rates of clinical pregnancy, live birth, and miscarriage between the blastocysts with TE grade A and B.

Conclusions

The blastocyst expansion stage, ICM grade, and TE grade are all associated with pregnancy outcomes. ICM grade is the strongest predictor of live birth. A blastocyst with stage 4-5, ICM grade A, and TE grade A/B should be given priority for single embryo transfer.

Blastocyst age, expansion, trophectoderm morphology, and number cryopreserved are variables predicting clinical implantation in single blastocyst frozen embryo transfers in freeze-only-IVF

PURPOSE

To determine which blastocyst assessment variables predict clinical implantations in single blastocyst frozen embryo transfers (FET) of freeze-only-IVF cycles, following improved vitrified-warmed blastocyst survival and developmental competence preservation.

METHOD

In this retrospective cohort study performed at a single private IVF center, the pregnancy outcomes of 1795 single blastocyst FET cycles were analyzed, from freeze-only-IVF retrievals performed between January 2017 and January 2020. Stepwise forward logistic regressions with clinical implantation (i.e., normal gestational sac and cardiac activity) as dependent variable were performed to identify the significant predictors. All blastocysts were vitrified using Cryotop technology, with before transfer (post-warming) blastocyst morphology scores used in all analyses.

RESULT(S)

The 1795 blastocysts transferred were vitrifıed on embryo days 4 (1057), 5 (716), and 6 (22). The overall clinical implantation rate was 50.9%; however, using blastocyst age and blastocyst morphological score the clinical implantation rates increased from 49.0% (day-4 1 and 2) and 25.2% (day-5 1 and 2) to 71.2% (day-4 4AA) and 64.3% (day-5 4AA), respectively. Whereas full (≥3) blastocysts with scores of AA and BA had similar clinical implantation rates (66.2 vs. 66.7%), the rate of full blastocysts with scores of AB was lower (58.9%). In stepwise forward logistic regressions, female age, blastocyst age, blastocyst expansion score, blastocyst trophectoderm score, and number of blastocysts vitrified were significant predictors of clinical implantation.

CONCLUSION(S)

Using blastocyst age and before transfer blastocyst expansion and trophectoderm morphology scores to select blastocysts, clinical implantation rates greater than 70% could be achieved for top-scoring blastocysts.

Clinical pregnancy is significantly associated with the blastocyst width and area: a time-lapse study

In order to maintain pregnancy rates following single embryo transfer, optimisation of embryo culture and selection is vital. Time-lapse monitoring (TLM) has the potential to play a crucial role by providing sequential images of embryo development and minimal disturbance. Therefore, in this study morphometric assessment of blastocyst area and maximum width was performed in order to evaluate if these parameters are associated with pregnancy outcomes in IVF/ICSI cycles. This is a retrospective study of 664 patients who had elective single blastocyst transfer (eSBT). The EmbryoScope drawing tools were used to measure specific variables such as the maximum blastocyst width and blastocyst area. Our results show that women who were pregnant had significantly (P < 0.01) larger blastocyst width [median (range) μm] 184 (125-239) versus non-pregnant, 160 (120-230)] and area [median (range) μm²] 26099 (12101-45,280) versus non-pregnant women, 22,251 (10992-37,931)]. A univariate logistic regression performed showed that blastocyst width [(OR = 1.026, 95% CI = (1.019, 1.033)] was significant (P < 0.01) and for every μm increase of blastocyst width, the odds of clinical pregnancy increase by 2.6%. A univariate logistic regression performed showed that blastocyst area [(OR = 1.00008, 95% CI = (1.00006, 1.00011)] was significant with P < 0.01. For every μm² increase of blastocyst area, our data showed the odds of clinical pregnancy increase by 0.008%. Hosmer-Lemeshow tests of calibrations were performed to verify calibration. Although our findings show a clear correlation between blastocyst dimensions and the clinical pregnancy rate, further studies are necessary to confirm these observations.

Analysis of Biochemical and Clinical Pregnancy Loss Between Frozen-Thawed Embryo Transfer of Blastocysts and Day 3 Cleavage Embryos in Young Women: A Comprehensive Comparison

BACKGROUND

To determine whether the embryo developmental stage affects biochemical or clinical pregnancy loss in young women undergoing frozen-thawed embryo transfer (FET) and to investigate the underlying mechanism.

METHODS

This was a retrospective study including a total of 18,34 β-HCG (human chorionic gonadotropin)-positive FET cycles. According to the morphological appearance (MA) of transferred blastocysts, FET cycles with blastocysts were divided into two groups: Group A: morphologically good (MG) blastocysts only, and Group B: at least one morphologically non-good (MNG) blastocyst. FET cycles with day 3 cleavage embryos were assigned as Group C. Biochemical and clinical pregnancy loss were the main outcome measures.

RESULTS

We predicted 78% in vivo-formed MG and 53.9% in vivo-formed day 5 blastocysts in Group C. (a) Including cases in Group A and Group B for binary logistic regression, we showed that Group B and day 6 blastocysts had significantly higher rates of BPL and CPL than Group A and day 5 blastocysts, respectively. (b) Including cases in Group A, Group B, and Group C for binary logistic regression, we showed that Group C had a significantly higher rate of BPL than Group A and day 5 blastocysts and a similar rate of BPL as Group B and day 6 blastocysts. Group C had a higher rate of CPL than Group A (p=0.071) and day 5 blastocysts (p=0.039), and a lower rate of CPL than Group B (p=0.199) and day 6 blastocysts (p=0.234).

CONCLUSIONS

(1) MA and days of usable blastocysts could serve as independent factors affecting the occurrence of BPL and CPL. (2) Transfer of day 3 cleavage embryos may produce "unusable blastocysts" in vivo, which significantly increased the rate of BPL. (3) The rate of CPL resulting from the transfer of day 3 embryos may depend on the rate of in vivo-formed MG or day 5 blastocysts. Our study indicated that the difference in the BPL or CPL between transfer of blastocysts and day 3 cleavage embryos may largely depend on the quality of embryos transferred.

Association between women's age and stage, morphology, and implantation of the competent blastocyst: a multicenter cohort study

OBJECTIVE

To study if the age of women undergoing assisted reproductive technology treatment associates with stage, morphology, and implantation of the competent blastocyst.

DESIGN

Multicenter historical cohort study based on exposure (age) and outcome data (blastocyst stage and morphology and initial human chorionic gonadotrophin [hCG] rise) from women undergoing single blastocyst transfer resulting in singleton pregnancy/birth.

SETTING

Sixteen private and university-based facilities.

PATIENT(S)

In this study, 7,246 women who, between 2014 and 2018, underwent controlled ovarian stimulation (COS) or frozen-thawed embryo transfer (FET) with a single blastocyst transfer resulting in singleton pregnancy were identified. Linking data to the Danish Medical Birth Registry resulted in a total of 4,842 women with a live birth being included.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The competent blastocyst development stage (1-6), inner cell mass (A, B, C), trophectoderm (A, B, C), and initial serum hCG value.

RESULT(S)

Adjusted analysis of age and stage in COS treatments showed that for every 1-year increase in age there was a 5% reduced probability of the competent blastocyst assessed as being in a high stage at transfer. Comparison between hCG values in women 18-24 years and 25-29 years in both COS and FET showed significantly lower levels in the youngest women.

CONCLUSION(S)

The initial hCG rise was influenced by the age of the woman, with an identical pattern for hCG values in COS and FET treatments. In COS, the competent blastocyst had a reduced stage with increasing women's age.

Embryo Selection Based on Morphological Parameters in a Single Vitrified-Warmed Blastocyst Transfer Cycle

The process of selecting a good quality embryo to improve the pregnancy outcomes is very important. The aim of our study was to elaborate the embryo selection process in a single vitrified-warmed blastocyst transfer (VBT) cycle by analyzing pre-vitrified and post-warmed blastocyst morphological factors to improve pregnancy outcomes. In this retrospective cohort study, we performed 329 single VBT cycles. The pre-vitrified and post-warmed morphological factors of all blastocysts were analyzed. Logistic regression analysis was conducted to select the independent morphological factor associated with ongoing pregnancy. The expansion of blastocoel (mid blastocoel; aOR 2.27, 95% CI.0.80-6.42, p = 0.12, expanded blastocoel; aOR 3.15, 95% CI.1.18-8.44, p = 0.02) in a pre-vitrified blastocyst and the grade of inner cell mass (ICM) (grade B; aOR 0.47, 95% CI.0.27-0.83, p = 0.01, grade C; aOR 0.22, 95% CI 0.09-0.56 p < 0.01) in post-warmed blastocysts significantly predicted the ongoing pregnancy. After fertilization, the embryo developed as a blastocyst on day 5 (day 5) showed a higher ongoing pregnancy than that on day 6 (day 6) (aOR 0.50, 95% CI.0.26-0.94, p = 0.03). The results suggest that while selecting a vitrified-warmed blastocyst in a single VBT cycle, the day 5 vitrified blastocyst should be considered, and a higher expansion grade in the pre-vitrified blastocyst should be selected. Our study has shown that post-warmed ICM grade tends to be a predictive indicator for the selection of the best blastocyst and allows for successful pregnancy, with ongoing pregnancy in a single blastocyst transfer.

Transfers of lower quality embryos based on morphological appearance result in appreciable live birth rates: a Canadian center's experience

Objective

To determine the reproductive outcomes resulting from transfer of lower-grade blastocysts to support the practice of cryopreserving and transferring lower-grade embryos.

Design

Retrospective chart review.

Setting

Single infertility center.

Patient(s)

Women who have undergone a fresh (n = 570) or frozen (n = 885) transfer of a single blastocyst embryo between December 2013 and December 2018.

Intervention(s)

None.

Main Outcome Measure(s)

The primary outcome was live birth rate. The secondary outcomes included implantation rate, ongoing pregnancy rate, associations with inner cell mass (ICM) and trophectoderm epithelium (TE) grades determined by morphological assessment, and antenatal/perinatal complications.

Results

Reproductive outcomes directly correlated with embryo quality. Transfers of AA embryos resulted in a 41.4% live birth rate compared to 31.1% for BB embryos and 13.3% for CC embryos. The TE grade was significantly associated with the live birth rate. Embryos with a TE grade of “B” had an odds ratio of 0.677 and embryos with a TE grade of “C” had an odds ratio of 0.394 compared to embryos with a TE grade of “A” for live birth.

Conclusion

Embryos with a TE “C” grade should be considered for transfer and cryopreservation, as they are shown to result in appreciable live birth rates. Such treatment should involve a thorough discussion with patients, however, as these live birth rates are significantly lower than those associated with higher-grade embryos.

Transfer the best and biopsy the rest? Blastocyst euploidy rates differ by morphology and day of biopsy

PURPOSE

To determine if blastocyst euploidy rates differ by embryo morphology or day of biopsy.

METHODS

We performed a retrospective analysis of euploidy rates based on patient age, overall embryo morphology grade (good, fair, or poor), and day of biopsy (days 5, 6, or 7) for blastocysts undergoing preimplantation genetic testing for aneuploidy (PGT-A). Our primary analysis included 904 embryos from oocytes age 33-39 years at retrieval.

RESULTS

In our primary analysis, euploidy rates were higher for good quality embryos than poor (64% vs. 48%, p < 0.01) and for fair quality embryos than poor (61% vs. 48%, p < 0.01). There was no significant difference in the euploidy rate between good and fair quality embryos (64% vs. 61%, p = 0.56). Embryos biopsied on day 5 were more likely to be euploid than embryos biopsied on day 6 (59% vs. 50%, p < 0.01) or day 7 (59% vs. 37%, p < 0.01). There was no significant difference in the euploidy rate between day 6 and day 7 embryos (50% vs. 37%, p = 0.07).

CONCLUSION

PGT-A may be more useful in cycles where a lower euploidy rate is expected based on age at oocyte retrieval, embryo morphology, and day of biopsy. There may be little benefit to biopsy of embryos with a high euploidy rate. Young patients with one or more good quality day 5 embryos may benefit from a "transfer the best fresh and biopsy the rest" strategy.

Blasts from the past: is morphology useful in PGT-A tested and untested frozen embryo transfers?

RESEARCH QUESTION

Day of cryopreservation, inner cell mass (ICM) grade, trophectoderm grade and blastocyst expansion grade have been associated with differences in live birth rate in frozen embryo transfer (FET) cycles. This study sought to examine the likelihood of live birth and whether the morphological grade of the blastocyst is more or equally useful in FET cycles among preimplantation genetic testing for aneuploidies (PGT-A) tested and untested blastocysts.

DESIGN

This was a retrospective cohort study of 6271 vitrified-warmed, autologous, single-embryo transfer cycles among patients undergoing IVF from July 2013 to December 2017 at a single, university-affiliated infertility practice. The primary outcome was live birth, calculated by generalized estimating equations.

RESULTS

Among PGT-A tested embryos, inferior ICM grade was associated with a lower chance of live birth (ICM grade B versus A: adjusted risk ratio [aRR] 0.91, 95% confidence interval [CI] 0.84-0.99). Among untested blastocysts there was a lower live birth rate in blastocysts cryopreserved on day 6 versus day 5 (aRR 0.87, 95% CI 0.78-0.96), and those with inferior pre-vitrification trophectoderm grade (trophectoderm grade B versus A: aRR 0.86, 95% CI 0.79-0.94). Blastocysts with a higher pre-vitrification expansion grade (pre-vitrification expansion grade 5 versus 4: aRR 1.1, 95% CI 1.01-1.2) were associated, but ICM grade was not associated (ICM grade B versus A: aRR 0.93, 95% CI 0.86-1.02), with chance of live birth.

CONCLUSIONS

Among PGT-A untested blastocysts, assessing embryo quality by day of cryopreservation, trophectoderm grade and expansion grade may help to identify embryos with the highest likelihood of live birth. Identifying euploid embryos by PGT-A appears to homogenize the cohort, making blastocyst morphological grade and day of cryopreservation less important.

PROGNOSTIC VALUE OF BLASTOCYST GRADE AFTER FROZEN EUPLOID EMBRYO TRANSFER IN PATIENTS WITH RECURRENT PREGNANCY LOSS

Objective

To determine if trophectoderm (TE) grade or inner cell mass (ICM) grade have predictive value after euploid frozen embryo transfer (euFET) among RPL patients.

Design

Retrospective cohort study.

Setting

Single fertility center, 2012-2018.

Patients

Patients with ≥ 2 prior pregnancy losses performing PGT-A with ≥1 euploid embryo for transfer.

Interventions

All patients underwent ICSI, trophectoderm biopsy, blastocyst grading and vitrification, and single euFET. Outcome of the first transfer was recorded.

Main Outcome Measures

Live birth (LB) and clinical miscarriage (CM) rates.

Results

660 euFET were included. In a binomial logistic regression analysis accounting for age, BMI, AMH and day of blastocyst biopsy, ICM grade C was not significantly associated with odds of live birth (aOR 0.50, 95% CI 0.24-1.02 p=0.057), miscarriage (aOR 1.67, 95% CI 0.56-5.00, p=0.36) or biochemical pregnancy loss (aOR 1.58, 95% CI 0.53-4.75, p=0.42). TE grade C was significantly associated with odds of live birth (aOR 0.49, 95% CI 0.28-0.86, p=0.01) and was not associated with odds of miscarriage (aOR 2.00, 95% CI 0.89-4.47, p=0.09) or biochemical pregnancy loss (aOR 1.85, 95% CI 0.77-4.44, p=0.17). Blastocyst grade CC had significantly lower LB rate compared to all other blastocyst grades (p<0.05, chi-square analysis).

Conclusion

Embryo grade CC and TE grade C are associated with decrease in odds of LB after euFET in RPL patients. Embryo grade is not associated with odds of CM in this cohort of RPL patients, suggesting that additional embryonic or uterine factors may influence risk of pregnancy loss.

Associations of post-warming embryo or blastocyst development with clinical pregnancy in vitrified embryo or blastocyst transfer cycles

Objective

To investigate whether the degree of post-warming embryo or blastocyst development is associated with clinical pregnancy in vitrified embryo or blastocyst transfer cycles.

Methods

Ninety-six vitrified cleavage-stage embryos and 58 vitrified blastocyst transfer cycles were selected. All transfer cycles were performed from February 2011 to March 2019, and all vitrified embryos or blastocysts were warmed from 4 PM to 6 PM and then transferred the next morning from 9 AM to 10 AM. The scores of the cleavage-stage embryos and blastocysts were assessed at warming and at transfer using the modified Steer method and the Gardner method, respectively. The mean embryo or blastocyst score, score of the single top-quality embryo or blastocyst, and the difference in the score between warming and transfer were compared between nonpregnant and pregnant women.

Results

In the cleavage-stage embryo transfer cycles, both the top-quality embryo score at transfer and the difference in the score between warming and transfer were significantly associated with clinical pregnancy. A top-quality embryo score at transfer of ≥60.0 (area under the curve [AUC], 0.673; 95% confidence interval [CI], 0.531–0.815) and a difference in the score between warming and transfer of ≥23.0 (AUC, 0.675; 95% CI, 0.514–0.835) were significant predictors of clinical pregnancy. In blastocyst transfer cycles, the top-quality blastocyst score at transfer was the only significant factor associated with clinical pregnancy. A top-quality blastocyst score at transfer of ≥38.3 was a significant predictor of clinical pregnancy (AUC, 0.666; 95% CI, 0.525–0.807).

Conclusion

The top-quality embryo score at transfer and the degree of post-warming embryo development were associated with clinical pregnancy in vitrified cleavage-stage embryo transfer cycles. In vitrified blastocyst transfer cycles, the top-quality blastocyst score at transfer was the only significant factor affecting clinical pregnancy.

Time of morulation and trophectoderm quality are predictors of a live birth after euploid blastocyst transfer: a multicenter study

OBJECTIVE

To investigate whether the morphodynamic characterization of a euploid blastocyst's development allows a higher prediction of a live birth after single-embryo-transfer (SET).

DESIGN

Observational cohort study conducted in two phases: training and validation.

SETTING

Private in vitro fertilization centers.

PATIENT(S)

Euploid blastocysts: 511 and 319 first vitrified-warmed SETs from 868 and 546 patients undergoing preimplantation genetic testing for aneuploidies (PGT-A) in the training and validation phase, respectively.

INTERVENTION(S)

Data collected from time of polar body extrusion to time of starting blastulation, and trophectoderm and inner-cell-mass static morphology in all embryos cultured in a specific time-lapse incubator with a continuous medium. Logistic regressions conducted to outline the variables showing a statistically significant association with live birth. In the validation phase, these variables were tested in an independent data set.

MAIN OUTCOME MEASURE(S)

Live births per SET.

RESULT(S)

The average live birth rate (LBR) in the training set was 40% (N = 207/511). Only time of morulation (tM) and trophectoderm quality were outlined as putative predictors of live birth at two IVF centers. In the validation set, the euploid blastocysts characterized by tM <80 hours and high-quality trophectoderm resulted in a LBR of 55.2% (n = 37/67), while those with tM ≥ 80 hours and a low-quality trophectoderm resulted in a LBR of 25.5% (N = 13/51).

CONCLUSION(S)

Time of morulation and trophectoderm quality are better predictors of a euploid blastocyst's reproductive competence. Our evidence was reproducible across different centers under specific culture conditions. These data support the crucial role of morulation for embryo development, a stage that involves massive morphologic, cellular, and molecular changes and deserves more investigation.

Association between the quality of inner cell mass and first trimester miscarriage after single blastocyst transfer

BACKGROUND

The blastocyst morphology provided valuable roles for predicting pregnancy and live birth, but was still not fully understood for evaluating miscarriage. The aim of this study was to explore the association between blastocyst morphologic evaluation and first trimester miscarriage combined with karyotype of miscarried conceptus.

METHODS

This retrospective cohort study included a total of 2873 clinical pregnancy cycles with single blastocyst transfer performed from January 2013 to April 2019. Chromosome karyotype of miscarried conceptus was analyzed via single nucleotide polymorphism array analysis. Miscarriage and karyotype of miscarried conceptus associated with blastocyst morphology were analyzed by chi-square and logistic regression analysis.

RESULTS

A total of 354 (12.3%) cycles resulted in first trimester miscarriage. Miscarriage rates increased with trophectoderm (TE) grade from A to C (P = 0.012), while three morphologic parameters (blastocoele expansion degree, inner cell mass (ICM) and TE) showed no statistical significance with miscarriage after multivariable analysis. The rate of aneuploidy was 47.7% (83 of 174) in total miscarried conceptuses. For euploid miscarriages, the grade B of ICM occupied a higher proportion compared with aneuploidy, with OR of 2.474, (95% CI, 1.311-4.699), P = 0.005.

CONCLUSIONS

Chromosomal aberration of embryo is an important genetic factor for first trimester miscarriage, and the quality of ICM is a potential indicator for euploid miscarriage. Blastocysts with grade A of ICM should be given priority during single blastocyst transfer to reduce potential miscarriage.

Association between blastocyst morphology and pregnancy and perinatal outcomes following fresh and cryopreserved embryo transfer

PURPOSE

To assess the importance of each blastocyst morphological criteria with pregnancy and perinatal outcomes.

METHODS

This single-center retrospective cohort study included blastocyst single embryo transfers (SET) performed between 1/2012-2/2018. Poisson regression was used to evaluate pregnancy outcomes following fresh and cryopreserved embryo transfer (CET) for association with blastocyst expansion, inner cell mass (ICM) quality, and trophectoderm (TE) quality. Among cycles resulting in live birth, associations with preterm birth, small for gestational age (SGA) and large for gestational age (LGA), were evaluated using logistic regression.

RESULTS

A total of 1023 fresh and 1222 CET cycles were included, of which 465 (45.1%) fresh and 600 (48.5%) CET cycles resulted in singleton live birth. Clinical pregnancy rates increased with increasing expansion among fresh transfers (p for trend = 0.001) but not CET (p = 0.221), and with TE quality for both fresh and CET cycles (p = 0.005 and < 0.0001, respectively). Live birth rates increased with increasing expansion (fresh p = 0.005, CET p = 0.018) and TE quality (fresh p = 0.028, CET p = 0.023). ICM grade was not associated with pregnancy outcomes; however, higher ICM quality among CET cycles was associated with increased chance of preterm birth (p = 0.005).

CONCLUSIONS

In blastocyst SET, blastocyst expansion and TE quality were each associated with clinical pregnancy and live birth. While higher ICM quality was associated with increased chance of preterm birth among CET, no other associations with perinatal outcomes were identified. Clinicians can be reassured that pregnancies from blastocysts with lower expansion, ICM, or TE qualities are not more likely to result in adverse perinatal outcomes.

Strategies in the transfer of varying grades of vitrified-warmed blastocysts in women aged over 35 years: A propensity-matched analysis

AIM

For in vitro fertilization, the optimal number of blastocysts to transfer according to blastocyst grade has not been well established, especially with respect to vitrified-warmed blastocyst transfer (VBT) in women aged over 35 years. This study aimed to compare the pregnancy and neonatal outcomes for three different VBT methods with variable numbers and qualities of blastocysts in women aged over 35 years.

METHODS

All VBT cycles were categorized into three groups according to blastocyst grade: GG (two good-quality blastocysts transferred), GP (one good-quality blastocyst transferred with one of poor quality) and GS (one good-quality blastocyst transferred). Blastocysts graded greater than or equal to 3BB were considered good quality. We conducted three 1:1 propensity score-matched analyses (GG vs GS, GP vs GS and GG vs GP) to compare the clinical pregnancy rate (CPR), live birth rate (LBR), multiple pregnancy rate (MPR), preterm birth rate and low birthweight rate.

RESULTS

Compared to GS, GG had higher CPR and LBR; however, MPR was also higher with GG. There were no significant differences, except implantation rate and MPR between GP and GS. Although implantation rate and CPR with GG were higher than those with GP, there were no significant differences in LBR and MPR.

CONCLUSION

To reduce high MPR after double blastocyst transfer methods, single good-quality blastocyst transfers are recommended in the VBT of women aged over 35 years. Transferring a good blastocyst with a poor one should be avoided because it confers no advantage.

The number of biopsied trophectoderm cells may affect pregnancy outcomes

OBJECTIVE

To study if the number of trophectoderm (TE) biopsied cells has an impact on implantation rates.

DESIGN

A retrospective cohort study in a single-center study.

SETTING

In vitro fertilization center.

PATIENTS

Patients who underwent PGT-A from January 2013 to March 2016. In total, 482 vitrified/warmed single embryo transfers were included.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Clinical pregnancies rate, implantation rate.

RESULTS

Overall, clinical pregnancies per embryo transfer were higher when a regular TE were biopsied compared to larger size biopsy cells (66% (175/267) vs 53% (115/215) (p < 0.005) respectively). Pregnancy rates were also analyzed according to embryo morphology at the moment of embryo biopsy, when a good-quality embryo was transferred the clinical outcome was 75% (81/108) in group 1 and 61% (60/99) in group 2 (p < 0.05). Data was also stratified by age in patients ≤ 35 years and > 35 years. The clinical pregnancy was 67% (51/76) in women ≤ 35 years and 65% (124/191) in women > 35 years when a regular size biopsy was performed. These results significantly reduced when a larger size biopsy was performed 54% (49/91) and 53% (66/124), respectively (p < 0.05). Further investigation indicated that miscarriage rate was similar between these groups (4% (7/182) in group 1 and 5% (6/121) in group 2).

CONCLUSIONS

These findings underscore that when a large amount of TE cells are biopsied, it may negatively affect implantation rates, but once implanted, the embryos have the same chance to miscarry or reach term.

Blastocyst development rate influences implantation and live birth rates of similarly graded euploid blastocysts

OBJECTIVE

To determine whether the blastocyst development rate, as assessed by the day of trophectoderm biopsy (day 5 vs. day 6), affects the live birth rate (LBR) of similarly graded euploid blastocysts.

DESIGN

Retrospective cohort study.

SETTING

Academic medical center.

PATIENT(S)

Patients who underwent frozen-thawed single euploid blastocyst transfers from 2013 to 2016 were included. Blastocyst morphologic grading was performed on day 5 or day 6 before the biopsy, with embryos designated into the following groups: good (3-6AA, 3-6AB, and 3-6BA), average (2-6BB), and poor (2-6BC and 2-6CB).

INTERVENTION(S)

Frozen-thawed embryo transfer.

MAIN OUTCOME MEASURE(S)

Implantation rate (IR) and LBR.

RESULT(S)

A total of 701 frozen-thawed single euploid blastocyst transfer cycles were included. Cycles in which day 5 blastocysts were transferred (n = 366) were associated with a significantly higher LBR than those in which day 6 blastocysts were transferred (n = 335; 60.4% vs. 44.8%). The odds ratio remained significant after controlling for all confounders, including the blastocyst grading. Furthermore, there was a significant difference in LBRs between good-quality, average-quality, and poor-quality blastocysts (67.8%, 53.4%, and 29.5%, respectively). Embryos reaching good-quality blastocysts on day 5 yielded significantly higher LBR (72.8% vs. 56.5%) and IR (77.7% vs. 58.7%) compared with those reaching similar quality blastocysts on day 6. Similarly, day 5 average-quality embryos conveyed a significantly higher IR compared with day 6 embryos of the same quality (64.4% vs. 53.4%).

CONCLUSION(S)

In addition to aneuploidy assessment, the speed of embryo development to the blastocyst stage and an evaluation of blastocyst morphology are critical to selecting the best embryo.

Can trophectoderm morphology act as a predictor for euploidy?

Objective

Euploid embryo transfers yield better implantation rates. In Brazil, morphological evaluation is performed to select the best embryos, since genetic analysis is still an expensive procedure. This study aimed to evaluate whether there is an association between trophectoderm morphology and ploidy status.

Methods

The study included 113 blastocysts formed in D5/D6 from 58 in vitro fertilization cycles held from January/2016 to May/2017. All patients with indication for PGD/PGS were included in the study. The mean age of the female patients was 37.04±5.65years. Biopsied blastocysts were categorized for morphology. Cells were sent for genetic analysis using the CGH array, SNP array or NGS techniques. Statistical analysis was performed using the chi square test, and statistical significance was assigned to differences with p≤0.05.

Results

Chromosome analysis revealed that 44 (38.9%) blastocysts were euploid. Blastocysts with trophectoderm grades A, B, and C had euploidy rates of 71.43%, 60% and 19.67%, respectively (p≤0.05).

Conclusion

Although the best trophectoderm morphology grades had higher euploidy rates, this indicator alone is not enough to warrant embryo genetic viability.

Extended culture of poor-quality supernumerary embryos improves ART outcomes

PURPOSE

The aims of this study were to investigate the possible benefits of extending the culture of poor-quality day-2 embryos (PQE) versus good-quality embryos (GQE) and to identify factors associated with pregnancy and live birth when transferring frozen-thawed blastocysts originating from GQE and PQE.

METHODS

This is a retrospective cohort follow-up study performed between November 2012 and February 2015 at the IVF Laboratory Unit of Cochin University Hospital (Paris, France) including 3108 day-2 supernumerary embryos resulting from 1237 IVF/ICSI cycles.

RESULTS

Total blastulation rate was 67.2% from GQE and 48.7% from PQE. Percentage of good-quality blastocysts was 60.7 and 47.9% respectively including 14.7 and 7.3% top-quality blastocysts. A total of 150 blastocysts originating from GQE and 729 from PQE were frozen, and then, 37 and 164 were thawed and transferred respectively resulting in 19 (51.4%) and 61 (37.9%) clinical pregnancies with 13 (35.1%) deliveries from GQE and 32 (19.9%) from PQE (p = 0.046) without any difference in neonatal outcomes. Quality of blastocysts that resulted in live birth was similar in the two groups. Women < 35 years old and day-5 blastocyst expansion were predictive of pregnancy and live birth.

CONCLUSIONS

(i) PQE are able to reach the blastocyst stage, to implant, and to give healthy babies and (ii) women age and day of blastocyst expansion are predictive of pregnancy and live birth.

Obstetric and perinatal outcomes of singletons after single blastocyst transfer: is there any difference according to blastocyst morphology?

A strong correlation between blastocyst morphology and implantation has been shown by many studies. The consequences and effects of assisted reproductive techniques on children's short and long-term health have always been a source of discussion. The obstetric and perinatal outcome of singletons according to blastocyst morphology has rarely been evaluated. The aim of this observational study is to determine whether a relationship exists between blastocyst morphology and obstetric and perinatal outcomes. A total of 799 singleton clinical pregnancies were analysed after transfer of a single fresh blastocyst on day 5 between 2006 and 2013. Blastocysts were divided into four groups based on their morphology on day 5: group 1 = good morphology blastocysts; group 2 = fair morphology blastocysts; group 3 = poor morphology blastocysts and group 4 = early (B1/B2) blastocysts. Obstetric and perinatal outcomes were compared between the four groups. After adjustment for some confounding variables, main obstetric and perinatal outcomes after transfer of blastocysts with poor morphological characteristics were not associated with increased adverse obstetric and perinatal events. Sex ratio was significantly higher in group 1 compared with groups 2, 3 and 4, and in Group 2 compared with Group 3 (P < 0.001) even after adjustment (P < 0.05).

Association between growth dynamics, morphological parameters, the chromosomal status of the blastocysts, and clinical outcomes in IVF PGS cycles with single embryo transfer

PURPOSE

The purpose of the present study is to examine interconnection between speed of embryo development, the genetic status of the blastocysts, and clinical outcomes in IVF preimplantation genetic screening (PGS) cycles with single embryo transfer (SET).

METHODS

The retrospective comparative study has been performed between January 2013 and January 2016. Seven hundred thirty-seven cycles of IVF treatment with PGS, followed by 503 SETs, were included in the study. Normally fertilized oocytes were hatched on day 3, were cultured to the blastocyst stage, and were biopsied only when at least three to seven cells were herniating from zona pellucida on the morning of day 5 (≤118 h) or day 6 (≥139 h). A total of 3705 embryos were analyzed for euploidy rates and blastocyst morphology. All embryos were vitrified after the biopsy, and selected embryos were subsequently thawed for a hormone replacement frozen embryo transfer cycle.

RESULTS

The euploidy rate was significantly higher among embryos biopsied on day 5 versus day 6: 59.44 ± 4.1 and 48.19 ± 3.8, respectively, p < 0.05. The difference in euploidy rates between embryos biopsied on day 5 versus day 6 in matched age groups increased from 5.83 to 25.46% with advancing maternal age. Our data demonstrated no statistically significant difference in euploidy rates between good-quality embryos biopsied on day 5 in the group of patients <38 years old and embryos in PGS cycles using donor oocytes: 71.12% (336/472) and 75.68% (221/292), respectively, p = 0.174, χ ² = 1.848. In 270 out of 503 SETs, transferred embryos were biopsied on day 5 (ongoing pregnancy rate was 64.6% in a group of patients <38 years old, and in a group of patients ≥38 years old, ongoing PR was 64.2%). In 233 out of 503 cycles, transferred embryos were biopsied on day 6 (ongoing PR was 46.6% in a group of patients <38 years old, and in a group of patients ≥38 years old, ongoing PR was 50.8%). In all study groups, the ongoing pregnancy rate was higher when the transferred embryo was available for biopsy on day 5.

CONCLUSIONS

Good- and fair-quality embryos available for biopsy on day 5 have higher euploidy rates and have a higher chance to result in an ongoing pregnancy. Euploidy rate has significant variations within the same age group depending on the morphology of the blastocysts.

Pregnancy rates for single embryo transfer (SET) of day 5 and day 6 blastocysts after cryopreservation by vitrification and slow freeze

PURPOSE

The purpose of this study was to compare clinical and ongoing pregnancy rates in cycles with single embryo transfer (SET) of blastocysts cryopreserved on day 5 or day 6. Our aim was to determine whether day 6 blastocysts perform adequately to recommend SET.

METHODS

Retrospective cohort study including 468 transfer cycles for 392 women younger than age 38 undergoing SET at a university-affiliated IVF clinic in the USA. A total of 261 day 5 blastocysts and 207 day 6 blastocysts for frozen-thawed SET between 2010 and 2016 were analyzed. Data included cryopreservation by both a slow freeze method and vitrification.

RESULTS

In total, 59.0% of day 5 SET cycles resulted in a clinical pregnancy compared to 54.1% of day 6 blastocysts (p = 0.54). Ongoing pregnancy rates from day 5 frozen-thawed blastocysts (51.7%) were comparable to day 6 (44.9%, p = 0.14). When looking at vitrified blastocysts only, there were no significant differences between day 5 and day 6 blastocysts, with a clinical pregnancy rate of 69.2% for day 5 and 72.5% for day 6 (p = 0.68).

CONCLUSIONS

SETs of day 6 cryopreserved blastocysts resulted in similar clinical and ongoing pregnancy rates compared to day 5, particularly after vitrification.

Clinical outcomes after IVF or ICSI using human blastocysts derived from oocytes containing aggregates of smooth endoplasmic reticulum

In this study the clinical and neo-natal outcomes after transfer of blastocysts derived from oocytes containing aggregates of smooth endoplasmic reticulum (SER) were compared between IVF and intracytoplasmic sperm injection (ICSI) cycles. Clinical and neo-natal outcomes of blastocysts in cycles with at least one SER metaphase II oocyte (SER + MII; SER + cycles) did not significantly differ between the two insemination methods. When SER + MII were cultured to day 5/6, fertilization, embryo cleavage and blastocyst rates were not significantly different between IVF and ICSI cycles. In vitrified-warmed blastocyst transfer cycles, the clinical pregnancy rates from SER + MII in IVF and ICSI did not significantly differ. In this study, 52 blastocysts (27 IVF and 25 ICSI) derived from SER + MII were transferred, yielding 15 newborns (5 IVF and 10 ICSI) and no malformations. Moreover, 300 blastocysts (175 IVF and 125 ICSI) derived from SER-MII were transferred, yielding 55 newborns (24 IVF and 31 ICSI cycles). Thus, blastocysts derived from SER + cycles exhibited an acceptable ongoing pregnancy rate after IVF (n = 125) or ICSI (n = 117) cycles. In conclusion, blastocysts from SER + MII in both IVF and ICSI cycles yield adequate ongoing pregnancy rates with neo-natal outcomes that do not differ from SER-MII.

Morphologic grading of euploid blastocysts influences implantation and ongoing pregnancy rates

OBJECTIVE

To determine whether blastocyst grading can predict pregnancy outcomes in the frozen-thawed embryo transfer (FET) of euploid blastocysts.

DESIGN

Retrospective cohort study.

SETTING

Academic medical center.

PATIENT(S)

Women who underwent FET of euploid embryo(s) between January 2013 and December 2015, with blastocysts were divided into four groups based on their morphologic grading before cryopreservation: excellent (≥3AA), good (3-6AB, 3-6BA, 1-2AA), average (3-6BB, 3-6AC, 3-6CA, 1-2AB, 1-2BA), and poor (1-6BC, 1-6CB, 1-6CC, 1-2BB).

INTERVENTION(S)

FET.

MAIN OUTCOMES MEASURE(S)

Ongoing pregnancy rate (OPR).

RESULT(S)

A total of 417 FET cycles (477 embryos) were included. Excellent-quality embryos (n = 38) yielded a statistically significantly higher OPR than poor-quality embryos (n = 106) (84.2% vs. 35.8%; adjusted odds ratio 11.0; 95% confidence interval, 3.8-32.1) and average-quality embryos (n = 197) (84.2% vs. 55.8%; adjusted odds ratio 4.8; 95% confidence interval, 1.7-13.3). Good-quality embryos (n = 76) were associated with a statistically significantly higher OPR than poor-quality embryos (61.8% vs. 35.8%). These odds ratios were adjusted for patient's age, body mass index, number of transferred embryos, type of frozen cycle, peak endometrial thickness, day of trophectoderm biopsy (5 or 6), and total number of euploid embryos for each patient. An inner cell mass grade of A yielded a statistically significantly higher OPR than ICM grade C (76.2% vs. 13.5%) or grade B (76.2% vs. 53.6%) after controlling for all confounders.

CONCLUSION(S)

Contrary to prior published studies, the current data suggest that blastocyst morphologic grading and particularly inner cell mass grade is a useful predictor of OPR per euploid embryo. Morphologic grading should be used to help in the selection among euploid blastocysts.

Grade of the inner cell mass, but not trophectoderm, predicts live birth in fresh blastocyst single transfers

Debate continues over which morphological parameter is most important in selecting blastocysts for transfer. We aimed to investigate which parameter more accurately predicts the occurrence of a live birth by designing a retrospective cohort study of 1084 fresh elective single blastocyst transfers. Primary outcome was live birth rate (LBR) and secondary outcomes were implantation, clinical pregnancy and early pregnancy loss rates. Blastocyst expansion and inner cell mass (ICM), but not trophoectoderm, were associated with LBR in the definitive multivariable regression analysis. When ICM grade dropped from A to C the likelihood of achieving a live birth was reduced by 55% (OR= 0.45, 95% CI 0.26-0.79, p = .005). These results were similar for clinical pregnancy rates. Early pregnancy loss rates of embryos with ICM grade C were more than double (38.0%) compared to those of grades A (15.95%) and B (17.17%, p = .002). The transfer of an embryo with an optimal inner cell mass reduces early pregnancy loss and increases the likelihood of a live birth. We did not find any significant association between trophectoderm and LBR in the multivariable analysis in contrast with recent studies.