Non-invasive embryo assessment in IVF

Lambalk, C.B. [Promotor]Schats, R. [Copromotor

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

Stadardization of catheter load speed during embryo transfer; comparison of manual and pump-regulated embryo transfer

The position of transfer air bubbles after embryo transfer is related to the pregnancy rate. With the conventional manual embryo-transfer technique it is not possible to predict the final position of the air bubbles. This position mainly depends on the catheter load speed at transfer (injection speed), a parameter that remains uncontrollable with the conventional technique even after standardization of the protocol. Therefore, the development of an automated device that generates a standardized injection speed is desirable. This study aimed to examine the variation in injection speeds in manual embryo transfer and pump-regulated embryo transfer (PRET). Seven laboratory technicians were asked to perform simulated transfers using the conventional embryo-transfer technique. Their injection speeds were compared with that of a PRET device. The results indicate that in manually performed transfers, even after standardization of the protocol, there is still a large variation in injection speed, while a PRET device generates a reliable and reproducible injection speed and therefore brings new possibilities for further standardization of the embryo-transfer procedure. Future research should reveal whether these experiments mimic real clinical circumstances and if a standardized injection speed results in more exact positioning of the transferred embryos and therefore higher pregnancy rates. The position of transfer air bubbles after embryo transfer is related to the pregnancy rate. With the currently used embryo-transfer technique, in which embryos are transferred manually with a syringe, we are not able to predict the final position of the air bubbles. This position depends on the injection speed of the syringe, which remains uncontrollable in embryo transfers that are performed manually even after standardization of the protocol. Therefore we developed an automated device that generates a reliable and reproducible injection speed, a pump-regulated embryo transfer (PRET) device. This study aimed to examine the variation in injection speeds in transfers performed manually and with the PRET device. Our results indicate that in manually performed transfers, even after standardization by protocol, there is still a large variation in injection speed and that the PRET device generates a reliable and reproducible injection speed and therefore brings new possibilities for further standardization of the embryo-transfer procedure. Future research should reveal whether our experiments mimic real clinical circumstances and if a standardized injection speed results in more exact positioning of the transferred embryos and therefore higher pregnancy rates. © 2011, Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved

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-

Comparing the cumulative live birth rate of cleavage-stage versus blastocyst-stage embryo transfers between IVF cycles: a study protocol for a multicentre randomised controlled superiority trial (the ToF trial)

Introduction In vitro fertilisation (IVF) has evolved as an intervention of choice to help couples with infertility to conceive. In the last decade, a strategy change in the day of embryo transfer has been developed. Many IVF centres choose nowadays to transfer at later stages of embryo development, for example, transferring embryos at blastocyst stage instead of cleavage stage. However, it still is not known which embryo transfer policy in IVF is more efficient in terms of cumulative live birth rate (cLBR), following a fresh and the subsequent frozen-thawed transfers after one oocyte retrieval. Furthermore, studies reporting on obstetric and neonatal outcomes from both transfer policies are limited. Methods and analysis We have set up a multicentre randomised superiority trial in the Netherlands, named the Three or Fivetrial. We plan to include 1200 women with an indication for IVF with at least four embryos available on day 2 after the oocyte retrieval. Women are randomly allocated to either (1) control group: embryo transfer on day 3 and cryopreservation of supernumerary good-quality embryos on day 3 or 4, or (2) intervention group: embryo transfer on day 5 and cryopreservation of supernumerary good-quality embryos on day 5 or 6. The primary outcome is the cLBR per oocyte retrieval. Secondary outcomes include LBR following fresh transfer, multiple pregnancy rate and time until pregnancy leading a live birth. We will also assess the obstetric and neonatal outcomes, costs and patients' treatment burden. Ethics and dissemination The study protocol has been approved by the Central Committee on Research involving Human Subjects in the Netherlands in June 2018 (CCMO NL 64060.000.18). The results of this trial will be submitted for publication in international peer-reviewed and in open access journals