Association of Trophectoderm mRNAs and MicroRNAs with Chromosomal Aneuploidy of Embryo

MicroRNAs (miRNAs) and mRNAs can serve as indicators of the chromosomal state of an embryo, with different profiles observed in euploid and aneuploid blastocysts. Examining the levels of miRNAs associated with aneuploidy and euploidy, as well as mRNAs related to implantation, can aid in predicting blastocyst chromosomal normality and improving assisted reproductive technology (ART) outcomes. This study analyzed chromosomal abnormality of 25 blastocysts using fluorescence in situ hybridization (FISH) and also the expression of genes ERBB4, SELL, ITGB3, and ITGAV, as well as miRNAs, miR-339, miR-27b, miR-661, miR-30c, miR-191, miR-345, miR-142, miR-141, miR-20a, and miR-372. We found that 17 out of 25 embryos were aneuploid. Moreover, results revealed lower expression levels of miR-30c and miR-372 in aneuploid embryos compared to euploid ones, while ITGAV and ITGB3 showed significantly higher expression in aneuploid embryos. These findings suggest that miR-372, miR-30c, ITGAV, and ITGB3 expression in trophectoderm cells can serve as biomarkers for assessing embryo health.

Reassessing the impact of letrozole co-administration in controlled ovarian hyperstimulation: findings from a single-center repeated measures study

PURPOSE

To explore whether letrozole improved outcomes in subsequent controlled ovarian hyperstimulation (COH) cycles.

METHODS

This was a retrospective repeated measures cohort study examining COH cycles. Patients were included if they underwent two cycles for unexplained infertility, male factor infertility, or planned oocyte/embryo cryopreservation. The first cycles for all patients implemented a non-letrozole, conventional gonadotropin protocol. Second cycles for the study group included letrozole (2.5-7.5 mg for 5 days) with no medication change to second cycles amongst controls. Our primary objective was to compare oocyte yield. Cohorts were then subdivided by pursuit of oocyte (OC) or embryo (IVF) cryopreservation. Secondary outcome amongst the OC subgroup was oocyte maturation index (metaphase II (MII)/total oocytes). Secondary outcomes amongst the IVF subgroup were normal fertilization rate (2-pronuclear zygotes (2PN)/oocytes exposed to sperm), blastocyst formation rate (blastocysts/2PNs), and embryo ploidy (%euploid and aneuploid).

RESULTS

Fifty-four cycles (n = 27) were included in letrozole and 108 cycles (n = 54) were included in control. Oocyte yield was higher in second cycles (p < 0.008) in the letrozole group but similar in second cycles (p = 0.26) amongst controls. Addition of letrozole did not impact MII index (p = 0.90); however, MII index improved in second cycles amongst controls (p < 0.001). Both groups had similar rates of normal fertilization (letrozole: p = 0.52; control: p = 0.61), blast formation (letrozole: p = 0.61; control: p = 0.84), euploid (letrozole: p = 0.29; control: p = 0.47), and aneuploid embryos (letrozole: p = 0.17; control: p = 0.78) between cycles.

CONCLUSIONS

Despite improved oocyte yield, letrozole did not yield any difference in oocyte maturation or embryo outcomes.

Preimplantation genetic testing in couples with balanced chromosome rearrangement: a four-year period real world retrospective cohort study

BACKGROUND

Couples with balanced chromosome rearrangement (BCR) are at high risk of recurrent miscarriages or birth defects due to chromosomally abnormal embryos. This study aimed to provide real-world evidence of the euploidy rate of blastocysts from couples with BCR using preimplantation genetic testing (PGT) and to guide pretesting genetic counselling.

METHODS

A continuous four-year PGT data from couples with BCR were retrospectively analyzed. Biopsied trophectoderm cells were amplified using whole genome amplification, and next-generation sequencing was performed to detect the chromosomal numerical and segmental aberrations. Clinical data and molecular genetic testing results were analyzed and compared among the subgroups.

RESULTS

A total of 1571 PGT cycles with 5942 blastocysts were performed chromosomal numerical and segmental aberrations detection during the four years. Of them, 1034 PGT cycles with 4129 blastocysts for BCR couples were included; 68.96% (713/1034) PGT cycles had transferable euploid embryos. The total euploidy rate of blastocysts in couples carrying the BCR was 35.29% (1457/4129). Couples with complex BCR had euploid blastocyst rates similar to those of couples with non-complex BCR (46.15% vs. 35.18%, P > 0.05). Chromosome inversion had the highest chance of obtaining a euploid blastocyst (57.27%), followed by Robertsonian translocation (RobT) (46.06%), and the lowest in reciprocal translocation (RecT) (30.11%) (P < 0.05). Couples with males carrying RobT had higher rates of euploid embryo both in each PGT cycles and total blastocysts than female RobT carriers did, despite the female age in male RobT is significant older than those with female RobT (P < 0.05). The proportions of non-carrier embryos were 52.78% (95/180) and 47.06% (40/85) in euploid blastocysts from couples with RecT and RobT, respectively (P > 0.05). RecT had the highest proportion of blastocysts with translocated chromosome-associated abnormalities (74.23%, 1527/2057), followed by RobT (54.60%, 273/500) and inversion (30.85%, 29/94) (P < 0.05).

CONCLUSIONS

In couples carrying BCR, the total euploidy rate of blastocysts was 35.29%, with the highest in inversion, followed by RobT and RecT. Even in couples carrying complex BCR, the probability of having a transferable blastocyst was 46.15%. Among the euploid blastocysts, the non-carrier ratios in RecT and RobT were 52.78% and 47.06%, respectively. RecT had the highest proportion of blastocysts with translocated chromosome-associated abnormalities.

Reproductive outcomes with delayed blastocyst development: the clinical value of day 7 euploid blastocysts in frozen embryo transfer cycles

Embryos of optimal development reach blastocyst stage 116 ± 2 h after insemination. Usable D7 blastocysts represent nearly 5% of embryos in IVF with acceptable pregnancy and live birth rates, however data are still limited. Therefore, this study aimed to analyze the ongoing pregnancy rate (OPR) of D7 blastocysts in single euploid frozen embryo transfer (FET) cycles. An observational study was performed including 1527 FET cycles with blastocysts biopsied on D5 (N = 855), D6 (N = 636) and D7 (N = 36). Blastocysts were classified as good (AA/AB/BA), fair (BB) or poor (AC/BC/CC/CA/CB) (Gardner scoring). FETs were performed in natural cycles (NC) or hormone replacement therapy (HRT) cycles. Patient's age differed significantly between D5, D6 and D7 blastocysts FET cycles (33.2 ± 5.6, 34.4 ± 5.3 and 35.9 ± 5.2, P < 0.001). OPRs were higher when D5 euploid blastocysts were transferred compared with D6 and D7 (56.0% vs. 45.3% and 11.1%, P < 0.001). Poor quality blastocysts were predominant in D7 blastocyst FET cycles (good quality: 35.4%, 27.2%, 5.6%; fair quality: 52.1%, 38.5%, 11.1%; poor quality: 12.5%, 34.3%, 83.3%, P < 0.001 for D5, D6 and D7 blastocysts; respectively). OPR was significantly reduced by D7 blastocyst FETs (OR = 0.23 [0.08;0.62], P = 0.004), patient's BMI (OR = 0.96 [0.94;0.98], P < 0.001), HRT cycles (OR = 0.70 [0.56;0.88], P = 0.002) and poor quality blastocysts (OR = 0.33 [0.24;0.45], P < 0.001). OPR is significantly reduced with D7 compared with D5/D6 euploid blastocysts in FET cycles. The older the patient, the more likely they are to have an FET cycle with blastocysts biopsied on D7, therefore culturing embryos until D7 can be a strategy to increase OPR outcomes in patients ≥38 years.

Deep learning system for classification of ploidy status using time-lapse videos

OBJECTIVE

To develop a spatiotemporal model for de prediction of euploid and aneuploid embryos using time-lapse videos from 10-115 hours after insemination (hpi).

DESIGN

Retrospective study.

MAIN OUTCOME MEASURES

The research used an end-to-end approach to develop an automated artificial intelligence system capable of extracting features from images and classifying them, considering spatiotemporal dependencies. A convolutional neural network extracted the most relevant features from each video frame. A bidirectional long short-term memory layer received this information and analyzed the temporal dependencies, obtaining a low-dimensional feature vector that characterized each video. A multilayer perceptron classified them into 2 groups, euploid and noneuploid.

RESULTS

The model performance in accuracy fell between 0.6170 and 0.7308. A multi-input model with a gate recurrent unit module performed better than others; the precision (or positive predictive value) is 0.8205 for predicting euploidy. Sensitivity, specificity, F1-Score and accuracy are 0.6957, 0.7813, 0.7042, and 0.7308, respectively.

CONCLUSIONS

This article proposes an artificial intelligence solution for prioritizing euploid embryo transfer. We can highlight the identification of a noninvasive method for chromosomal status diagnosis using a deep learning approach that analyzes raw data provided by time-lapse incubators. This method demonstrated potential automation of the evaluation process, allowing spatial and temporal information to encode.

Human Uterine Lavage: First Live Births from In Vivo Conceived Genetically Screened Blastocysts

INTRODUCTION

We wish to report the first live births from genetically screened human euploid blastocysts obtained by uterine lavage. The embryos transferred to infertile women were previously obtained using a novel fully automated uterine lavage catheter and fluid recovery device developed for this indication. The objective of this portion of the research was to confirm embryo implantation and live births with these unique in vivo conceived blastocysts obtained by uterine lavage.

METHODS

In vivo conceived embryos recovered by uterine lavage 5 days after intrauterine insemination were available for embryo donation. In vivo embryos were the result of prior controlled ovarian stimulation cycles in oocyte donors and intrauterine insemination with donor sperm. An observational case series of nine embryo transfer procedures was performed at an outpatient fertility center. One to two embryos were transferred to eight infertile women since one woman had two separate embryo transfer procedures.

RESULTS

Nine embryo transfer procedures were performed with 14 blastocysts in eight women resulting in a blastocyst implantation rate of 36% (5/14) and live birth rate of 44% (4/9). Five infants have been born from the four delivered pregnancies with one set of twins.

CONCLUSIONS

This is the first report of live births from genetically screened human euploid blastocysts obtained by uterine lavage. The nonsurgical uterine lavage office procedure represents the only current approach to obtain in vivo conceived embryos and can provide a benchmark for comparison to standard in vitro cultured blastocysts. Live births of in vivo conceived blastocysts represent the validation that the nonsurgical uterine lavage procedure allows simplified access to naturally conceived embryos without performing the surgical procedure of an oocyte aspiration. Owing to its simplicity, uterine lavage may be useful in screening embryos for preimplantation genetic testing for aneuploidy in fertile and infertile couples.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (Identifier NCT03426007).

Pregnancy and neonatal outcomes of letrozole versus natural cycle frozen embryo transfer of autologous euploid blastocyst

PURPOSE

To investigate the pregnancy and neonatal outcomes of letrozole-stimulated frozen embryo transfer (LTZ-FET) cycles compared with natural FET cycles (NC-FET).

METHODS

Our retrospective cohort included all LTZ-FET (n = 161) and NC-FET (n = 575) cycles that transferred a single euploid autologous blastocyst from 2016 to 2020 at Stanford Fertility Center. The LTZ-FET protocol entailed 5 mg of daily letrozole for 5 days starting on cycle day 2 or 3. Outcomes were compared using absolute standardized differences (ASD), in which a larger ASD signifies a larger difference. Multivariable regression models adjusted for confounders: maternal age, BMI, nulliparity, embryo grade, race, infertility diagnosis, and endometrial thickness.

RESULTS

The demographic and clinical characteristics were overall similar. A greater proportion of the letrozole cohort was multiparous, transferred high-graded embryos, and had ovulatory dysfunction. The cohorts had similar pregnancy rates (67.1% LTZ vs 62.1% NC; aOR 1.31, P = 0.21) and live birth rates (60.9% LTZ vs 58.6% NC; aOR 1.17, P = 0.46). LTZ-FET neonates on average were born 5.7 days earlier (P < 0.001) and had higher prevalence of prematurity (18.6% vs. 8.0%NC, ASD = 0.32) and low birth weight (10.4% vs. 5.0%, ASD = 0.20). Both cohorts' median gestational ages (38 weeks and 1 day for LTZ; 39 weeks and 0 day for NC) were full term.

CONCLUSION

There were similar rates of pregnancy and live birth between LTZ-FET and NC-FET cycles. However, there was a higher prevalence of prematurity and low birth weight among LTZ-FET neonates. Reassuringly, the median gestational age in both cohorts was full term, and while the difference in gestational length of almost 6 days does not appear to be clinically significant, this warrants larger studies.

Nomogram based on clinical and laboratory characteristics of euploid embryos using the data in PGT-A: a euploid-prediction model

BACKGROUND

The evaluation of embryo morphology may be inaccurate. A euploid prediction model is needed to provide the best and individualized counseling about embryo selection based on patients and embryo characteristics.

METHODS

Our objective was to develop a euploid-prediction model for evaluating blastocyst embryos, based on data from a large cohort of patients undergoing pre-implantation genetic testing for aneuploidy (PGT-A). This retrospective, single-center cohort study included data from 1610 blastocysts which were performed PGT-A with known genetic outcomes. The study population was divided into the training and validation cohorts in a 3:1 ratio. The performance of the euploid-prediction model was quantified using the area under the receiver operating characteristic (ROC) curve (AUC). In addition, a nomogram was drawn to provide quantitative and convenient tools in predicting euploid.

RESULTS

We developed a reliable euploid-prediction model and can directly assess the probability of euploid with the AUC (95%CI) of 0.859 (0.834,0.872) in the training cohort, and 0.852 (0.831,0.879) in the validation cohort, respectively. The euploid-prediction model showed sensitivities of 0.903 and specificities of 0.578.

CONCLUSIONS

The euploid-prediction model is a reliable prediction model and can directly assess the probability of euploid.

Live birth rate following a euploid blastocyst transfer is not affected by double vitrification and warming at cleavage or blastocyst stage

PURPOSE

To compare reproductive outcomes following a euploid embryo transfer, between those embryos vitrified-warmed twice to those vitrified-warmed once.

METHODS

We retrospectively analysed 694 single euploid frozen embryo transfer cycles following preimplantation genetic testing for aneuploidy (PGT-A). For cycles in group 1 (N = 451), embryos were biopsied for PGT-A at blastocyst stage and vitrified. For cycles in group 2 (N = 146), embryos were vitrified at blastocyst stage, before being warmed and biopsied for PGT-A and vitrified again. For cycles in group 3 (N = 97), embryos were vitrified on day-3, before being warmed, cultured to day-5 and biopsied for PGT-A and re-vitrified.

RESULTS

The pregnancy, clinical pregnancy and livebirth rate in group 2 were not statistically different to group 1 (pregnancy rate, adjusted OR 1.09, 95% CI 0.62-1.91; clinical pregnancy, aOR 0.89, 95% CI 0.58-1.37; live birth rate, aOR 0.85, 95% CI 0.56-1.28). There was also no significant difference between group 3 and group 1, with similar pregnancy rate (aOR 1.22, 95% CI 0.74-1.99), clinical pregnancy rate (aOR 1.21, 95% CI 0.75-1.96) and live birth rate (aOR 1.15, 95% CI, 0.73-1.80). There was no significant difference in miscarriage rates between all three groups. The age at the oocyte collection, embryo quality and day of biopsy were associated with pregnancy, clinical pregnancy and live birth rate.

CONCLUSION

This study suggests that vitrifying and warming embryos twice at blastocyst or at cleavage and then blastocyst stage, can lead to similar reproductive outcomes to embryos vitrified-warmed once, after a single euploid embryo transfer.

Cumulus cells of euploid versus whole chromosome 21 aneuploid embryos reveal differentially expressed genes

RESEARCH QUESTION

Can cumulus cells be used as a non-invasive target for the study of determinants of preimplantation embryo quality?

DESIGN

Cumulus cells were collected from monosomy 21, trisomy 21 and euploid embryos and subjected to RNA sequencing analysis and real-time polymerase chain reaction assays. The differential gene expression was analysed for different comparisons.

RESULTS

A total of 3122 genes in monosomy 21 cumulus cells and 19 genes in trisomy 21 cumulus cells were differentially expressed compared with euploid cumulus cells. Thirteen of these genes were differentially expressed in both monosomy and trisomy 21, compared with euploid, including disheveled segment polarity protein 2 (DVL2), cellular communication network factor 1 (CCN1/CYR61) and serum response factor (SRF), which have been previously implicated in embryo developmental competence. In addition, ingenuity pathway analysis revealed cell-cell contact function to be affected in both monosomy and trisomy 21 cumulus cells.

CONCLUSIONS

These findings support the use of cumulus cell gene expression analysis for the development of biomarkers evaluating oocyte quality for patients undergoing fertility preservation of oocytes.

Association between morphologic grading and implantation rate of Euploid blastocyst

BACKGROUND

Standard morphologic evaluation has been the most widely adopted approach to embryo selection, and remains the most common strategy.The objective of the study to determine the association between the morphologic grading and implantation rate of euploid blastocysts in single frozen-thawed embryo transfer (SET) cycles.

METHODS

A total of 271 patients aged 20-40 years undergoing euploid SET from January 2017 to December 2019 were included in retrospective cohort study.The cycles were divided into three groups based on their morphologic grading before cryopreservation: good-quality (n = 58), average-quality (n = 88) and poor-quality blastocysts (n = 125). The pregnancy outcome of the three morphologic groups were analyzed and a logistic regression of implantation rate was conducted.

RESULTS

Good-quality blastocysts yielded statistically significantly higher implantation rates than poor-quality (79.31% vs. 48%; P<0.001). Planned subgroup analyses by age and the day of TE biopsy were conducted. Logistic regression analyses that adjusted for these variables identified higher implantation rates (adjusted odds ratio(aOR) = 4.083, 95% confidence interval (CI):1.836-9.082, P<0.001) for the good-quality blastocysts than for those that underwent poor-quality cycles in women aged < 35 years, but not in women aged ≥35 years (aOR = 6.074, 95% CI: 0.456-80.919, P = 0.172). The implantation rates were higher among women with good-quality blastocysts on both Day 5 and Day 6 of TE biopsy than among those with poor-quality blastocysts (Day 5, aOR = 3.294, 95% CI:1.260-8.616, P = 0.015; Day 6, aOR = 4.179, 95% CI:1.004 ~ 17.399, P = 0.049). Day 5 euploid blastocysts had no significant difference in implantation potential and early spontaneous abortion rate compared with similarly graded Day 6 euploid blastocysts.

CONCLUSIONS

Blastocyst morphologic grading was associated with implantation rate for euploid embryo transfers after adjustment for potential confounders. These findings suggest that evaluating blastocyst morphology is critical when selecting the best euploid blastocyst.

Live birth rate from euploid blastocysts is not associated with infertility etiology or oocyte source following frozen-thawed embryo transfer (FET): analysis of 4148 cycles reported to SART CORS

PURPOSE

To investigate whether live birth rates from euploid blastocyst frozen-thawed embryo transfer (FET) cycles are associated with infertility diagnosis or oocyte source.

DESIGN

Retrospective analysis of FET cycles reported to SART CORS in 2014.

METHODS

Data from fresh IVF cycles with preimplantation genetic testing for aneuploidy (PGT-A), linked to the first FET cycles, were collected from the 2014 SART CORS database for autologous and donor oocyte cycles. Inclusion criteria were patients undergoing FET with euploid embryos (n = 4148). Demographic data including age, BMI, prior fertility, and etiology of infertility were collected from the retrieval cycle and analyzed. Patients with uterine anomalies, preimplantation genetic testing-mutation (PGT-M) for genetic diseases, gender selection, HLA determination, or systemic and immunologic disorders were excluded. The primary outcome measure was live birth (LB) rate. Potential confounders such as age, prior fertility, and maximum baseline FSH values were analyzed with regression models as indicated.

RESULTS

Though age, maximum baseline FSH, and infertility diagnosis were significantly different, LB was similar between patients undergoing autologous or donor oocyte FET cycles. Etiology of infertility was not significantly associated with LB in autologous cycles (p = 0.95). Potential confounders such as maternal age, prior fertility, and maximum baseline FSH were not associated with outcomes; however, maternal BMI was inversely related to LB in autologous cycles, with an odds ratio of 0.97 (95% CI: 0.96-0.98 (rho = - 0.08, p < 0.01)).

CONCLUSIONS

After controlling for confounding variables, a euploid embryo derived from a donor or autologous oocyte results in similar LB in women with different infertility diagnoses.

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.

Shooting STAR: reinterpreting the data from the ‘Single Embryo TrAnsfeR of Euploid Embryo’ randomized clinical trial

Preimplantation genetic testing for aneuploidy (PGT-A) still remains controversial in clinical practice. Recently, the randomized controlled trial, 'Single Embryo TrAnsfeR of Euploid Embryo' (STAR) by Munné and coworkers showed a similar live birth rate per intention to treat in the two study groups (PGT-A and controls). A wrong diagnosis and/or biopsy-related damage to the embryo might underlie these results. To assess the impact of these factors on the efficiency of PGT-A, the live birth rate of 'euploid' embryos transferred in the PGT-A group was compared with its ideal value, namely the live birth rate of embryos with the potential to implant and to give rise to a baby in the control group. This estimate has been derived using the results of the genetic testing reported in the STAR trial. According to this model, the STAR trial has demonstrated that transferring only blastocysts classified as 'euploid' after PGT-A leads to a reduction from 82.2% to 50.0% of the live birth rate for competent embryos, thus supporting the idea that PGT-A is associated with some embryo wastage.

Euploid miscarriage is associated with elevated serum C-reactive protein levels in infertile women: a pilot study

Purpose

Increased serum C-protein (CRP) levels reduce fecundity in healthy eumenorrheic women with 1–2 pregnancy losses. Subclinical systemic inflammation may impede maternal immune tolerance toward the fetal semi-allograft, compromising implantation and early embryonic development. Some miscarriages with normal karyotypes could, therefore, be caused by inflammation. Whether pre-pregnancy CRP relates to karyotypes of spontaneously aborted products of conception (POCs) was investigated.

Methods

A study cohort of 100 infertile women with missed abortions who underwent vacuum aspirations followed by cytogenetic analysis of their products of conception tissue was evaluated at an academically affiliated fertility center. Since a normal female fetus cannot be differentiated from maternal cell contamination (MCC) in conventional chromosomal analyses, POC testing was performed by chromosomal microarray analysis. MCC cases and incomplete data were excluded. Associations of elevated CRP with first trimester pregnancy loss in the presence of a normal fetal karyotype were investigated.

Results

Mean patients’ age was 39.9 ± 5.8 years; they demonstrated a BMI of 23.9 ± 4.6 kg/m² and antiMullerian hormone (AMH) of 1.7 ± 2.4 ng/mL; 21.3% were parous, 19.1% reported no prior pregnancy losses, 36.2% 1–2 and 6.4% ≥ 3 losses. Karyotypes were normal in 34% and abnormal in 66%. Adjusted for BMI, women with elevated CRP were more likely to experience euploid pregnancy loss (p = 0.03). This relationship persisted when controlled for female age and AMH.

Conclusions

Women with elevated CRP levels were more likely to experience first trimester miscarriage with normal fetal karyotype. This relationship suggests an association between subclinical inflammation and miscarriage.

Euploid rates among oocyte donors: is there an optimal age for donation?

PURPOSE

To examine cycle blastocyst euploid rates among age subgroups of oocyte donors.

METHODS

Retrospective cohort analysis of ova donation in vitro fertilization cycles (OD-IVF) for which trophectoderm biopsy for preimplantation genetic testing for aneuploidy (PGT-A) by array comparative genomic hybridization (aCGH) or next generation gene sequencing (NGS) was employed between January 2015 and December 2018 in a single high-volume fertility center.

RESULTS

Compared to oocyte donors age 26-30, oocyte donors age ≤ 25 had similar cycle blastocyst euploid rates (80 [66.7, 87.5]%, vs. 75 [62.5, 87.5]%, median [IQR], p = 0.07), blastocyst formation rates (66.7 [50, 75]%, vs. 62.5 [52, 75]%, p = 0.55), and number of retrieved oocytes (29 [23, 37] vs. 27 [20, 35], p = 0.18). Age of oocyte donor from 18 to 34 was not correlated with cycle blastocyst euploid rate.

CONCLUSION

Oocyte donors age ≤ 25 had similar cycle blastocyst euploid rates, blastocyst formation rates, and number of retrieved oocytes compared to donors age 26-30. There was no correlation between cycle blastocyst euploid rates and age of the oocyte donor from 18 to 34 years. Given the lack of significant age-related change in cycle blastocyst euploid rates, our data support existing practices which do not favor a specific age subgroup of young oocyte donors.

Is there an association between oocyte number and embryo quality? A systematic review and meta-analysis

This systematic review and meta-analysis determined the association between aspirated after ovarian stimulation and top/good quality embryos obtained in women undergoing ovarian stimulation for IVF/intracytoplasmic sperm injection (ICSI). MEDLINE, EMBASE, Scopus, CINAHL and Web of Science were searched for English-language publications on top/good-quality embryos at cleavage (day 2/3) and/or blastocyst (day 5/6) developmental stages, up to 18 November 2017. Twenty-eight studies (three prospective and 25 retrospective) reporting data on 291,752 assisted reproductive technology (ART) cycles were considered eligible. We confirmed a strong positive association between oocytes retrieved and top/good-quality day 2/3 embryos (weighted correlation coefficient [r_w] = 0.791), day 5/6 embryos (r_w = 0.901), metaphase II oocytes (r_w = 0.988), oocytes exhibiting two pronuclei (r_w = 0.987) and euploid embryos (r_w = 0.851); P < 0.001 for all correlations (evaluated in subsets of the 17 studies). Data from 5657 cycles showed that the group with the most oocytes aspirated had the most top/good-quality day 2/3 embryos (pooled standardized mean differences (high [>15] versus low [<4] 1.91, 95% confidence interval [CI] 1.05-2.77, P < 0.0001; high versus medium [4-15] 1.15, 95% CI 0.74-1.55, P < 0.0001; medium versus low 1.41, 95% CI 0.79-2.03, P < 0.0001). Individual participant meta-analysis would enable accurate determination of these associations and other outcomes.

Euploid blastocysts implant irrespective of their morphology after NGS-(PGT-A) testing in advanced maternal age patients

PURPOSE

Does blastocyst morphology following euploid elective single embryo transfer (eSET) after preimplantation genetic testing for aneuploidies (PGT-A) via next generation sequencing impact clinical outcome?

METHODS

Two hundred ninety-six patients underwent PGT-A. Of 1549 blastocysts, 1410 blastocysts had a conclusive result after PGT-A and were included for analysis. An eSET policy was followed in a frozen embryo replacement cycle. A total of 179 euploid blastocysts were thawed and transferred. Clinical outcomes were categorized in four different embryo quality groups: excellent, good, average and poor.

RESULTS

Euploidy rate was 19/36 (52.7%, 95% CI 37-68), 199/470 (42.3%, 95% CI 38-47), 156/676 (23.0%, 95% CI 20-26) and 39/228 (17.1%, 95% CI 13-23) in the excellent, good, average and poor quality blastocyst groups, respectively. Fitted logistic regression analysis taking into account the following covariables: female, age, embryo chromosomal status and day of blastocyst development/biopsy showed that morphology was predictive of the comprehensive chromosome screening result (p < 0.05). A logistic regression analysis was also performed on clinical outcomes taking into account the effect of blastocyst morphology and day of blastocyst development/biopsy. None of the parameters were shown to be significant, suggesting morphology and day of blastocyst development/biopsy do not reduce the competence of euploid embryos (p > 0.05).

CONCLUSIONS

After eSET, implantation rate was 80-86%; live birth rate per embryo transfer was 60-73% and clinical miscarriage rate was found to be < 10% and were not significantly affected by the embryo morphology. Results are concordant with those reported when using aCGH and highlights the competence of poor-quality euploid embryos.

Early human embryos are naturally aneuploid-can that be corrected?

Aneuploidy is common and may be a natural occurrence in early human embryos. Selecting against embryos containing aneuploid cells for embryo transfer has been reported to increase clinical pregnancies per transfer in some studies, but not others. Some aneuploidy is due to misallocation of chromosomes during meiosis, in either the egg or sperm, but most aneuploidy is due to misallocation of chromosomes during mitoses after fertilization. Big questions are as follows: Why does this happen? How much aneuploidy in a preimplantation embryo is compatible with normal fetal development? Is aneuploidy increased by in vitro culture, and/or could it be prevented or corrected in the IVF lab?