An overview of the available methods for morphological scoring of pre-implantation embryos in in vitro fertilization

Small extracellular vesicles in follicular fluids for predicting reproductive outcomes in assisted reproductive technology

BACKGROUND

Assisted reproductive technology accounts for an increasing proportion of infertility treatments, and assessments to predict clinical pregnancy outcomes are desired. Extracellular vesicles exist in follicular fluid, and small non coding RNAs in extracellular vesicles underline the possibility of reflecting pregnancy potential.

METHODS

Follicular fluid samples are collected from 20 ovarian follicles of 15 infertile patients undergoing assisted reproductive technology. Extracellular vesicles are isolated by serial centrifugation and small RNA sequencing is performed to investigate the profiles of microRNAs and P-element-induced wimpy testis-interacting RNAs.

RESULTS

Small extracellular vesicles with a size range of approximately 100 nm are successfully isolated, and the small non coding RNA profiles of pregnant samples (n = 8) are different from those of non-pregnant samples (n = 12). Fourteen dysregulated small non coding RNAs are selected to identify the independent candidates [mean read count >100, area under the curve >0.8]. Among them, we find that a specific combination of small non coding RNAs (miR-16-2-3p, miR-378a-3p, and miR-483-5p) can predict the pregnant samples more precisely using a receiver operating characteristics curves analysis (area under the curve: 0.96). Furthermore, even in the same patients, the three microRNAs are differentially expressed between pregnant and non-pregnant samples.

CONCLUSIONS

Our results demonstrate that small non coding RNAs derived from small extracellular vesicles in follicular fluid can be potential non-invasive biomarkers for predicting pregnancy, leading to their probable application in assisted reproductive technology. Further large-scale studies are required to validate the clinical usefulness of these small non coding RNAs.

Delineating the heterogeneity of embryo preimplantation development using automated and accurate morphokinetic annotation

PURPOSE

Our objective was to design an automated deep learning model that extracts the morphokinetic events of embryos that were recorded by time-lapse incubators. Using automated annotation, we set out to characterize the temporal heterogeneity of preimplantation development across a large number of embryos.

METHODS

To perform a retrospective study, we used a dataset of video files of 67,707 embryos from four IVF clinics. A convolutional neural network (CNN) model was trained to assess the developmental states that appear in single frames from 20,253 manually-annotated embryos. Probability-weighted superposition of multiple predicted states was permitted, thus accounting for visual uncertainties. Superimposed embryo states were collapsed onto discrete series of morphokinetic events via monotonic regression of whole-embryo profiles. Unsupervised K-means clustering was applied to define subpopulations of embryos of distinctive morphokinetic profiles.

RESULTS

We perform automated assessment of single-frame embryo states with 97% accuracy and demonstrate whole-embryo morphokinetic annotation with R-square 0.994. High quality embryos that had been valid candidates for transfer were clustered into nine subpopulations, as characterized by distinctive developmental dynamics. Retrospective comparative analysis of transfer versus implantation rates reveals differences between embryo clusters as marked by poor synchronization of the third mitotic cell-cleavage cycle.

CONCLUSIONS

By demonstrating fully automated, accurate, and standardized morphokinetic annotation of time-lapse embryo recordings from IVF clinics, we provide practical means to overcome current limitations that hinder the implementation of morphokinetic decision-support tools within clinical IVF settings due to inter-observer and intra-observer manual annotation variations and workload constrains. Furthermore, our work provides a platform to address embryo heterogeneity using dimensionality-reduced morphokinetic descriptions of preimplantation development.

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

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

Fresh or Frozen Embryo Transfer in The Antagonist In Vitro Fertilization Cycles: A Retrospective Cohort Study

BACKGROUND

Gonadotropin-releasing hormone antagonist (GnRH-ant), widely adopted protocol, is more in line with the physiological processes, and induces a shorter and more cost-effective ovarian stimulation. In order to assess the success rate of embryo transferring (ET) in the antagonist in vitro fertilization (IVF) cycles, we compared the fresh ET with the frozen ET outcomes.

MATERIALS AND METHODS

In this retrospective cohort study, one hundred five cases of ET of the infertility clinic of the Besat hospital (Kurdistan, Iran) between March 2014 to March 2020 that were treated with antagonist cycle (both fresh and frozen) were analyzed. The difference between the two groups in baseline data and reproductive outcomes were evaluated using Independent sample t test, Mann-Whitney U test, Chi-squared test, and Fisher's exact test in SPSS software (version 22).

RESULTS

Out of 105 cases, 48 and 57 were in the fresh and frozen ET groups, respectively. The participants age was 35.75 ± 4.9 Y. In the fresh ET group, and 33.98 ± 5.1 Y in the frozen ET group. The percentage of chemical pregnancy was 12 (25%) in the fresh ET group and 15 (26.3%) in the frozen ET group (P=0.8); Clinical pregnancy rate was 11 (22.9%) in the fresh ET group and 11 (19.3%) in the frozen ET group (P=0.6); the rate of abortion in the fresh ET group was 3 (6.3%, P=0.2), and in the frozen ET group was 8 (14%, P=0.2); and the live birth rate was 9 (18.8%) in the fresh ET group, in comparison with 7 (12.3%) in the frozen ET group (P=0.3).

CONCLUSION

Not statistically significant, the percentage of chemical pregnancy and abortion were higher in the frozen ET group. The percentage of clinical pregnancy and live birth were higher in the fresh ET group.

Stabilization of F-Actin Cytoskeleton by Paclitaxel Improves the Blastocyst Developmental Competence through P38 MAPK Activity in Porcine Embryos

Changes in F-actin distribution and cortical F-actin morphology are important for blastocyst developmental competence during embryogenesis. However, the effect of paclitaxel as a microtubule stabilizer on embryonic development in pigs remains unclear. We investigated the role of F-actin cytoskeleton stabilization via P38 MAPK activation using paclitaxel to improve the developmental potential of blastocysts in pigs. In this study, F-actin enrichment and adducin expression based on blastomere fragment rate and cytokinesis defects were investigated in cleaved embryos after in vitro fertilization (IVF). Adducin and adhesive junction F-actin fluorescence intensity were significantly reduced with increasing blastomere fragment rate in porcine embryos. In addition, porcine embryos were cultured with 10 and 100 nM paclitaxel for two days after IVF. Adhesive junction F-actin stabilization and p-P38 MAPK activity in embryos exposed to 10 nM paclitaxel increased significantly with blastocyst development competence. However, increased F-actin aggregation, cytokinesis defects, and over-expression of p-P38 MAPK protein by 100 nM paclitaxel exposure disrupted blastocyst development in porcine embryos. In addition, exposure to 100 nM paclitaxel increased the misaligned α-tubulin of spindle assembly and adhesive junction F-actin aggregation at the blastocyst stage, which might be caused by p-P38 protein over-expression-derived apoptosis in porcine embryos.

Early Compaction Might Be a Parameter to Determine Good Quality Embryos and Day of Embryo Transfer in Patients Undergoing Intracytoplasmic Sperm Injection

Introduction: Compaction is the first event in embryo morphogenesis. Blastocyst transfer on day five or six has been widely performed in the last decade. We investigated the clinical value of early compaction on day three for evaluation of the transferred embryo quality and pregnancy.

Methods: Four hundred patients with female factor infertility and 776 fresh embryo transfers were included. Two groups were formed: Early compaction group had embryo transfer with at least one day-three embryo exhibiting early compaction. Transferred embryos without early compaction comprised the control group. Embryo transfer was performed on day three or five after the assessment of embryo compaction by a time-lapse technology system. Each patient underwent only a single cycle of embryo transfer. We analyzed fertilization, pregnancy, and live birth rates.

Results: We detected significantly higher numbers of the retrieved oocytes, metaphase II (MII) oocytes, and fertilized oocytes in the early compaction group. Moreover, the transfer of the early compacting embryos on day three resulted in higher pregnancy and live birth rates.

Conclusion: Our data suggest that early compaction might be a factor to determine good quality embryos and embryo transfer day.

Is it necessary to monitor the serum luteinizing hormone (LH) concentration on the human chorionic gonadotropin (HCG) day among young women during the follicular-phase long protocol? A retrospective cohort study

BACKGROUND

The normal physiological function of LH requires a certain concentration range, but because of pituitary desensitization, even on the day of HCG, endogenous levels of LH are low in the follicular-phase long protocol. Therefore, our study aimed to determine whether it is necessary to monitor serum LH concentrations on the day of HCG (LH_HCG) and to determine whether there is an optimal LH_HCG range to achieve the desired clinical outcome.

METHODS

A retrospective cohort study included 4502 cycles of in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) from January 1, 2016, to June 30, 2019, in a single department. The main outcome measures included retrieved eggs, available embryos, and live birth rate.

RESULTS

The LH_HCG was divided into five groups: Group A (LH ≤ 0.5), Group B (0.5 IU/L < LH ≤ 1.2 IU/L), Group C (1.2 IU/L < LH ≤ 2.0 IU/L), Group D (2.0 IU/L < LH ≤ 5.0 IU/L), Group E (LH > 5 IU/L). In terms of the numbers of retrieved eggs (15.22 ± 5.66 vs. 13.54 ± 5.23 vs. 12.90 ± 5.05 vs. 12.30 ± 4.88 vs. 9.6 ± 4.09), diploid fertilized oocytes (9.85 ± 4.70 vs. 8.69 ± 4.41 vs. 8.39 ± 4.33 vs. 7.78 ± 3.96 vs. 5.92 ± 2.78), embryos (7.90 ± 4.48 vs. 6.83 ± 4.03 vs. 6.44 ± 3.88 vs. 6.22 ± 3.62 vs. 4.40 ± 2.55), and high-quality embryos (4.32 ± 3.71 vs. 3.97 ± 3.42 vs. 3.76 ± 3.19 vs. 3.71 ± 3.04 vs. 2.52 ± 2.27), an increase in the LH_HCG level showed a trend of a gradual decrease. However, there was no significant difference in clinical outcomes among the groups (66.67% vs. 64.33% vs. 63.21% vs. 64.48% vs. 63.33%). By adjusting for confounding factors, with an increase in LH_HCG, the number of retrieved eggs decreased (OR: -0.351 95%CI - 0.453-[- 0.249]).

CONCLUSION

In the follicular-phase long protocol among young women, monitoring LH_HCG is recommended in the clinical guidelines to obtain the ideal number of eggs.

Body mass index, not race, may be associated with an alteration in early embryo morphokinetics during in vitro fertilization

OBJECTIVE

To assess the relationship between maternal body mass index (BMI) and embryo morphokinetics on time-lapse microscopy (TLM).

DESIGN

Retrospective cohort study.

METHODS

All IVF cycles between June 2015 and April 2017 were reviewed. Female BMI prior to egg retrieval was collected through chart review. BMI (kg/m2) classification included underweight (< 18.5), normal weight (18.5-25), overweight (25-30), and obese (≥ 30). Embryos' morphokinetic parameters were assessed with TLM and included time to syngamy, 2-cell, 3-cell, 4-cell, and 8-cell. A generalized linear mixed model was used to control for potential confounders and multiple embryos resulting from a single IVF cycle.

RESULTS

A total of 2150 embryos from 589 IVF cycles were reviewed and included in the analysis. Classification based on BMI was as follows: underweight (N = 56), normal weight (N = 1252), overweight (N = 502), and obese (N = 340). After adjusting for race and use of intracytoplasmic sperm injection, the mean time to the 8-cell stage in the underweight group was 4.3 (95% CI: - 8.31, - 0.21) h less than in the normal weight group (P = 0.025) and 4.6 (95% CI: - 8.8, - 0.21) h less than in the obese group (p = 0.022). No significant difference was noted between race and TLM after controlling for possible confounders.

CONCLUSIONS

Embryos from underweight women were demonstrated to have a faster time to the 8-cell stage than normal weight or obese women. No significant difference was noted for race. This study demonstrates that weight can be a factor contributing to embryo development as observed with TLM.

MicroRNAs secreted by human embryos could be potential biomarkers for clinical outcomes of assisted reproductive technology

Introduction

MicroRNAs (miRNAs) are important regulators of many biological functions, including embryo implantation and development. Recently, it has been reported that miRNAs in biofluids are predictive for physiological and pathological processes.

Objectives

In this study, we aim to investigate whether the miRNAs secreted by human embryos in culture medium can be used as embryonic biomarkers.

Methods

The culture media were prospectively collected from embryos of patients at reproductive medicine center with informed consent. A high-throughput miRNA sequencing method was applied to detect the miRNA profiles in the human embryo culture media. After bioinformatics analysis and screening of differentially expressed miRNAs, quantitative real-time polymerase chain reaction (qRT-PCR) assay was subsequently performed to further confirm the sequencing results with mixed samples. Furthermore, we performed droplet digital PCR (ddPCR) to verify the target miRNAs at single sample level. Receiver operating characteristic (ROC) analyses were performed for differentially expressed miRNAs.

Results

Compared with embryos with failed pregnancy, the embryos with successful pregnancy secreted different miRNA profiles into the culture media, which were predicted to be involved in multiple biological processes. Validated by droplet digital polymerase chain reaction (ddPCR), the expression of hsa-miR-26b-5p and hsa-miR-21-5p in the culture media of cleavage embryos with successful pregnancy was significantly lower than that of embryos with failed pregnancy. Moreover, the Receiver Operating Characteristic (ROC) curve analysis indicated that hsa-miR-26b-5p and hsa-miR-21-5p could serve as potential biomarkers for reproductive outcomes.

Conclusion

Together, our findings highlight the important predictive potential of miRNAs secreted by human embryos in culture media, which is meaningful for non-invasive embryo selection in assisted reproductive technology.

A New Day 4 Grading System to Assess Embryo Quality in Frozen Embryo Transfer Cycles

To present a new day 4 (D4) embryo grading system to assess embryos in frozen-thawed embryo transfer (FET) cycles. A new grading system (grades A-E) was developed from the 2011 ESHRE Istanbul Consensus for D4 embryos in FET cycles. Embryos with complete compaction were classified as grade A; those with partial compaction were assigned as grade B; and those without compaction were classified as grades C, D, and E according to their different blastomere number ratio (BNR; number of embryo blastomeres on D4/number of embryo blastomeres on D3, D4/D3). Embryos with a BNR of ≥ 1.5 were defined as grade C, those with a BNR of ≥ 1.2 and < 1.5 were defined as grade D, and those with a BNR of ≥ 1.0 and < 1.2 were defined as grade E. Using this proposed grading model, 5460 embryos with known implantation data were retrospectively analyzed after D4 transfer in FET cycles. The transferred embryos exhibited a similar declining trend in implantation and live birth rates from the top grade A to the lowest grade E. The in vitro fertilization group showed increased implantation rates of grade B and E embryos compared with the intracytoplasmic sperm injection group (grade B: 41.99%, 34.63%, χ² = 5.84, p < 0.05 and grade E: 18.98%, 14.08, χ² = 75.62, p < 0.01). Receiver-operating characteristic analysis revealed that our proposed model predicted the implantation outcomes and live birth rates of all embryos (area under the curve = 0.65; 95% confidence interval [CI],0.63-0.66; p < 0.01 and AUC = 0.73; 95%CI, 0.65-0.84; p < 0.001, respectively). This study demonstrates that the new grading system provided by us can be a useful tool for assisting embryo selection via changes in embryo morphology. D4 embryo transfer provides a simple and applicable method for FET cycles in daily practice.

Lapatinib Decreases the Preimplantation Aneuploidy Rate of in vitro Fertilized Mouse Embryos without Affecting Completion of Preimplantation Development

One of the major reasons for implantation failure and spontaneous abortion is a high incidence of preimplantation chromosomal aneuploidy. Lapatinib simultaneously inhibits EGFR and HER2, leading to apoptosis. We hypothesized a higher sensitivity for aneuploid cells in preimplantation embryos to lapatinib based on reports of aneuploid cell lines being sensitive to some anticancer drugs. Late 2-cell mouse embryos were treated with lapatinib after determining a nontoxic dose. Morphologies were recorded 24, 48, and 60 hours later. The effect of lapatinib on the aneuploidy rate was evaluated by studying blastocyst cells using FISH. Although the rate of development to 8-cell and morula stage was higher in the control group (p < 0.05), there was no difference in development to the blastocyst stage at the same studied intervals between lapatinib-treated and control groups (p = 0.924). The mean number of cells in morula and blastocyst stages were not different between the groups (p = 0.331 and p = 0.175, respectively). The frequency of aneuploid cells and diploid embryos was, respectively, significantly lower and higher in lapatinib-treated embryos, (p < 0.001). Since lapatinib treatment reduced the aneuploidy rate without impact on the development of mouse preimplantation embryos to the blastocyst stage and number of total cells, lapatinib seems useful for prevention of preimplantation aneuploidy in in vitro fertilization.

Evaluating the value of day 0 of an ICSI cycle on indicating laboratory outcome

A number of oocyte characteristics have been associated with fertilization, implantation and live-birth rates, albeit without reaching a consensus. This study aims to delineate possible associations between oocyte characteristics, oocyte behavior during intracytoplasmic sperm injection (ICSI), fertilization potential, and laboratory outcomes. Four-hundred and seventy-seven patients, yielding 3452 oocytes, were enrolled in this prospective observational study from 2015 to 2018. Οoplasm granularity was associated with poor embryo quality and higher probabilities of post-ICSI oocytes and embryos discarded in any developmental stage and never selected for embryo transfer or cryopreservation (p < 0.001). Both sudden or difficult ooplasm aspiration, and high or lack of resistance during ICSI were associated with either a poor Zygote-Score or fertilization failure (p < 0.001). Sudden or difficult ooplasm aspiration and high resistance during ICSI penetration were positively associated with resulting to a post-ICSI oocyte or embryo that would be selected for discard. Evaluation of oocyte characteristics and oocyte behavior during ICSI may provide early information regarding laboratory and cycle outcomes. Particularly, ooplasm granularity, and fragmentation of polar body, along with sudden or difficult ooplasm aspiration and high or lack of resistance during ICSI penetration may hinder the outcome of an ICSI cycle. The associations presented herein may contribute towards development of a grading system or a prediction model. Taking into account information on oocytes and ICSI behavior may effectively assist in enhancing IVF outcome rates.

Mining of variables from embryo morphokinetics, blastocyst's morphology and patient parameters: an approach to predict the live birth in the assisted reproduction service

Based on growing demand for assisted reproduction technology, improved predictive models are required to optimize in vitro fertilization/intracytoplasmatic sperm injection strategies, prioritizing single embryo transfer. There are still several obstacles to overcome for the purpose of improving assisted reproductive success, such as intra- and inter-observer subjectivity in embryonic selection, high occurrence of multiple pregnancies, maternal and neonatal complications. Here, we compare studies that used several variables that impact the success of assisted reproduction, such as blastocyst morphology and morphokinetic aspects of embryo development as well as characteristics of the patients submitted to assisted reproduction, in order to predict embryo quality, implantation or live birth. Thereby, we emphasize the proposal of an artificial intelligence-based platform for a more objective method to predict live birth.

Urinary Organophosphate Metabolite Concentrations and Pregnancy Outcomes among Women Conceiving through in Vitro Fertilization in Shanghai, China

BACKGROUND

Animal studies suggest that pesticide exposure elicits endocrine changes, increases embryo implantation failure, and decreases litter size. However, only a few epidemiological studies have evaluated the effects of pesticides on the outcomes of in vitro fertilization (IVF) pregnancies.

OBJECTIVES

This study examined the associations between preconception organophosphate pesticides (OP) exposure and pregnancy outcomes among women undergoing IVF in a Chinese population.

METHODS

This study included 522 women with infertility who underwent IVF. Women were recruited from a prospective study, the China National Birth Cohort (CNBC), from Shanghai, China, between July 2017 and December 2018. Demographic and clinical information were collected from medical records and through questionnaires. Preconception exposure to OP was assessed by measuring six nonspecific dialkylphosphate (DAP) metabolites [diethylthiophosphate (DETP), diethylphosphate (DEP), diethyldithiophosphate (DEDTP), dimethylthiophosphate (DMTP), dimethylphosphate (DMP), dimethyldithiophosphate (DMDTP)] in urine samples collected at recruitment. Generalized estimating equation (GEE) models were used to evaluate the associations between OP and pregnancy outcomes.

RESULTS

Compared with women in the lowest quartile (Q1) of individual DEP and Σ4DAP (the sum of DMP, DMTP, DEP, and DETP), women in the highest quartile (Q4) had lower odds of successful implantation, clinical pregnancy, and live birth, and most of the negative trends were significant (p-trends<0.05). There were no significant associations between urinary DAP concentrations and early IVF outcomes, including total and mature oocyte counts, best embryo quality, fertilization, E2 trigger levels, and endometrial wall thickness.

CONCLUSION

Preconception OP exposure was inversely associated with successful implantation, clinical pregnancy, and live birth in women who underwent IVF. https://doi.org/10.1289/EHP7076.

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

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

The complex microbiome from native semen to embryo culture environment in human in vitro fertilization procedure

BACKGROUND

Only a few microbial studies have conducted in IVF (in vitro fertilization), showing the high-variety bacterial contamination of IVF culture media to cause damage to or even loss of cultured oocytes and embryos. We aimed to determine the prevalence and counts of bacteria in IVF samples, and to associate them with clinical outcome.

METHODS

The studied samples from 50 infertile couples included: raw (n = 48), processed (n = 49) and incubated (n = 50) sperm samples, and IVF culture media (n = 50). The full microbiome was analyzed by 454 pyrosequencing and quantitative analysis by real-time quantitative PCR. Descriptive statistics, t-, Mann-Whitney tests and Spearman's correlation were used for comparison of studied groups.

RESULTS

The study involved normozoospermic men. Normal vaginal microbiota was present in 72.0% of female partners, while intermediate microbiota and bacterial vaginosis were diagnosed in 12.0 and 16.0%, respectively. The decreasing bacterial loads were found in raw (35.5%), processed (12.0%) and sperm samples used for oocyte insemination (4.0%), and in 8.0% of IVF culture media. The most abundant genera of bacteria in native semen and IVF culture media were Lactobacillus, while in other samples Alphaproteobacteria prevailed. Staphylococcus sp. was found only in semen from patients with inflammation. Phylum Bacteroidetes was in negative correlation with sperm motility and Alphaproteobacteria with high-quality IVF embryos.

CONCLUSION

Our study demonstrates that IVF does not occur in a sterile environment. The prevalent bacteria include classes Bacilli in raw semen and IVF culture media, Clostridia in processed and Bacteroidia in sperm samples used for insemination. The presence of Staphylococcus sp. and Alphaproteobacteria associated with clinical outcomes, like sperm and embryo quality.

Adjusted mitochondrial DNA quantification in human embryos may not be applicable as a biomarker of implantation potential

OBJECTIVE

To evaluate the feasibility of adjusted mitochondrial DNA quantification in human embryos as a biomarker for implantation potential.

DESIGN

Double-blind, observational, prospective analysis of an Asian population in a single university-affiliated in vitro fertilization center. A total of 1617 embryos derived from 380 infertile couples were collected. The DNA from blastomere biopsy (n = 99) or trophectoderm biopsy (n = 1518) were analyzed with next-generation sequencing.

RESULTS

The adjusted mtDNA quantification followed a non-normal distribution in both types of the embryos. When stratified by ploidy status, the adjusted mtDNA quantification was significantly higher in aneuploid trophectoderm than in euploid cells, but not in blastomeres. The adjusted mtDNA quantification of embryos showed significant but very weak positive correlation in total trophectoderm cells with maternal age (Spearman's correlation, r = 0.095, p = 0.0028) but neither in blastomeres nor stratified by ploidy status. The median adjusted mtDNA quantification was also significantly higher in aneuploid blastocysts than in euploid ones while corrected with embryo morphology. Viable embryos did not contain significantly different quantities of adjusted mtDNA compared with nonviable embryos (implanted n = 103, non-implanted n = 164; median 0.00097 vs. 0.00088, p = 0.21) in 267 transferred blastocysts.

CONCLUSION

Quantification of adjusted mitochondria DNA in human embryos was significantly lower in euploid blastocysts than in aneuploid blastocysts. However, no statistically significant differences regarding implantation outcome were evident. To our best knowledge, this study provides the largest scale and the first correlation data between mitochondria copy number and human embryo implantation potential in Asians.

Blastocyst classification systems used in Latin America: is a consensus possible?

OBJECTIVE

To identify different blastocyst classification systems used by embryologists in Latin American countries and evaluate the possibility of establishing a consensus among these countries.

METHODS

An E-mail survey was carried out through the Latin American Network of Assisted Reproduction (REDLARA) aimed at embryologists from assisted reproduction centers in Latin countries.

RESULTS

Sixty surveys were collected from 12 Latin American countries, of which 66.7% had >10years of professional practice as embryologists. Seven different blastocyst classification systems were reported, of which 5 have previously been described in the literature.

CONCLUSION

Although the group of embryologists surveyed use different blastocyst classification systems, most in this group consider that the embryo score system should be unified in their countries as well as in the region.

Raman spectrum: A potential biomarker for embryo assessment during in vitro fertilization

The aim of the study was to investigate whether Raman spectrum is consistent with the morphological scoring of the embryo of day 3 during in vitro fertilization (IVF). The spent culture media of embryo of day 3 from 10 patients were collected and analyzed. The samples were analyzed using Raman spectroscopy and graded according to the standard embryo scoring system simultaneously. Data showed that the Raman spectra obtained from the droplet of media were useful, as they can act as the characteristic signature for protein and amino acids. The Raman biospectroscopy-based metabonomics profiling of spent media was consistent with the result of conventional morphological evaluation. In conclusion, this technology offers great potential for the development of tools allowing rapid non-invasive assessment of the quality of embryo of day 3 during IVF.