The association of the blastomere volume index (BVI), the blastomere symmetry index (BSI) and the mean ovality (MO) with ongoing implantation after single embryo transfer

PURPOSE: To generate novel, objective variables that resemble embryo quality and relate them to ongoing implantation, using multilevel imaging of single-transferred embryos. METHODS: Retrospective analysis of multilevel images of 659 day 3 single-transferred embryos. Each embryo was photographed on seven different levels, in order to measure the largest diameter of every blastomere within an embryo. The volume of each blastomere was calculated using the equation [Formula: see text]. The blastomere volume index (BVI) represented the ratio between the total blastomeric volume of an embryo and the mean cytoplasmic volume of an oocyte on day 0. The blastomere symmetry index (BSI) represented the ratio between the greatest blastomere volume and the smallest blastomere volume within an embryo. The mean ovality (MO) represented the presence of non-spherical blastomeres. Analyses were performed to compare the BVI, BSI and MO between patients with and without an ongoing implantation. RESULTS: The mean BVI was significantly higher for embryos in the ongoing implantation group compared to the no ongoing implantation group. The mean BSI was associated with ongoing implantation for unevenly cleaved embryos. The MO of blastomeres within an embryo was similar for embryos in the ongoing implantation group compared to the no ongoing implantation group. The association of the BVI and BSI with ongoing implantation was confounded, because only female age and cleavage rate were significantly associated with ongoing implantation in multiple logistic regression analyses. CONCLUSIONS: The BVI, BSI and MO are objective variables that resemble embryo quality, but they are not suitable to use as embryo selection tools

Making zero-liquid discharge desalination greener: utilising low-grade heat and vacuum membrane distillation for the regeneration of volatile draw solutes

Desalination is still a rather energy intensive process, and is also associated with the discharge of highly saline and chemically contaminated brine; both these factors detract from the sustainability of the desalination process. Fortunately, both these issues can be addressed by developing zero-liquid discharge (ZLD) processes that can be powered by low-grade (LG) heat sources. The objective of the current work is to improve upon the world's first commercial forward osmosis ZLD system (developed by OASYS Water) by employing mainly LG heat. In the original system, the principal energy cost was associated with the regeneration of the thermo-responsive ammonia‑carbon dioxide draw solution, which was performed in a distillation column (DC). In this paper, a novel flow process is developed in which the same volatile draw solution is regenerated using a combined vacuum membrane distillation (VMD) and distillation column (DC) system. The numerical results indicate that the standard DC draw solute regeneration system (DSR) outperforms the newly proposed VMD-DC DSR system when latent heat is available. However, when only sensible heat is available, the novel VMD-DC DSR system can reduce the overall energy consumption by more than 15% to 20% at source temperatures of 90 °C and 85 °C, respectively. Although these energy savings are substantial and allow for the efficient integration of various renewable and waste heat sources, the VMD-DC system still faces several drawbacks, such as high cooling loads and the regeneration of a more diluted draw solution. These difficulties originate from the non-selectivity of the VMD process and its difficult heat integration. The numerical results presented here show the huge potential of membrane-based DSR systems for the recovery of volatile draw solutes. Nevertheless, the proposed DSR system will benefit from further optimisation via inclusion of more selective (e.g. pervaporation) or better heat integrated (e.g. multi-stage VMD) membrane processes to improve its technical and economical performance

Non-invasive viability assessment of day-4 frozen-thawed human embryos using near infrared spectroscopy

This study investigated if metabolomic profiling of culture media using near infrared (NIR) spectroscopy was related to live-birth rates after single-embryo transfer of frozen-thawed embryos. Analysis of culture media of frozen-thawed embryos was performed by NIR spectroscopy. A viability score was calculated using a predictive multivariate algorithm of fresh day-5 embryos with known pregnancy outcomes. This algorithm generated with fresh day-5 embryos could help to identify the live-birth group from the no live-birth group. Multivariable regression models that tested the predictive ability of the viability score for live birth showed an odds ratio in the crude analysis of 1.50 (P = 0.008), after adjustment for embryo morphology, 1.44 (P = 0.022), and after adjustment for all variables, 1.71 (P = 0.005); based on a 0.1 step increase in viability scores. In conclusion, higher viability scores resulted in higher live-birth rates. An algorithm generated from fresh embryos might be used to predict viability of frozen-thawed embryos. Frozen-thawed embryos have different metabolic activity which is related to implantation potential. Therefore, this method might be useful to select the best embryo for transfer within a group of embryos with similar morphology. In frozen-thawed embryo transfer (FET) cycles, usually more than one embryo is transferred. However, elective single embryo transfer (SET) might be effective in FET cycles when a good-quality embryo is selected. Viability assessment of frozen-thawed embryos is usually performed by morphological assessment. Although very helpful, morphological assessment remains subjective and can be unreliable in predicting embryo viability. New parameters to predict embryo viability, including non-invasive metabolomic profiling, have recently been studied. Metabolomics is the study of small-molecule metabolite byproducts left behind from cellular processes. By measuring byproducts of the embryonic metabolism in spent embryo culture media, a snapshot of the physiology of an embryo is obtained, which translates to viability. In this study, we investigated if metabolomic profiling by near infrared (NIR) spectroscopy was related to live-birth rates after SET of frozen-thawed embryos. Analysis of spent culture media of frozen-thawed embryos was performed by NIR spectroscopy and a viability score was calculated. The mean viability score from embryos with known implantation potential was significantly higher than the mean viability score of embryos which failed to implant: i.e. higher viability scores resulted in higher live-birth rates. Individual embryos showed a positive relationship between increased viability scores and increased live-birth rates. In other words, frozen-thawed embryos (of the same morphological grade) have different metabolic activity which is related to implantation potential. This indicates that the use of morphological and metabolomic criteria can both help with the decision of which embryo to transfer after thawing. © 2011 Elsevier Inc. All rights reserved

No evidence that embryo selection by near-infrared spectroscopy in addition to morphology is able to improve live birth rates: results from an individual patient data meta-analysis

STUDY QUESTIONWhat is the value of embryo selection by metabolomic profiling of culture medium with near-infrared (NIR) spectroscopy as an adjunct to morphology, compared with embryo selection by morphology alone, based on an individual patient data meta-analysis (IPD MA)?SUMMARY ANSWERThe IPD MA indicates that the live birth rate after embryo selection by NIR spectroscopy and morphology is not significantly different compared with the live birth rate after embryo selection by morphology alone.WHAT IS KNOWN ALREADYRetrospective proof of principle studies has consistently shown that high NIR viability scores are correlated with a high implantation potential of embryos. However, randomized controlled trials (RCTs) have generally shown no benefit of the NIR technology over embryo morphology, although there have been some conflicting results between pregnancy outcomes on different days of embryo transfer.STUDY DESIGN, SIZE, DURATIONThis IPD MA included all existing RCTs (n = 4) in which embryo selection by morphology was compared with embryo selection by morphology and the use of NIR spectroscopy of spent embryo culture medium by the Viametrics-