Knowledge Sharing

2010.09.07

New Trends in the European Society of Human Reproduction and Embryology (ESHRE) in Rome 2010

Reproductive Research Dr. HUANG,JUN-JIA

European Society of Human Reproduction and Embryology (ESHRE)is one of largest annual events in assisted reproductive medicine. Each year, it attracts elites in the reproductive medicine community around the world and gathers for a lively discussion. The venue of the meeting is held in turn in major cities in Europe in the end of June and the beginning of July, the most pleasant seasons in Europe. This year ESHRE was held in Rome, Italy. Rome is a well-known historical city. Because it is my first time to visit Rome, I am eager for this trip. But I also heard of thebad traffic and lots of crime in Italy, I took the flight there with the mind full of expectation yet being afraid of heart-brokening.

When I first arrived in Rome, I was attracted by historic buildings and countless statues.The roads are not very wide, aswhat we usually see in a modern metropolis, therefore there are many one-way streets; the venue for the conference is not in the urban area, but in the suburbs, adjacent to the new International Convention Center exhibition near the airport, public transit was very inconvenient; the fastest way to get from the urban area to the venue is to take a taxi, but it also took 30-40 minutes; if you take the subway and then shuttle bus to the conference, it took 50 minutes at the fastest. I think it is because there is no such large place in the urban area to accommodate so many people.

As in previous years, I had to do my homework thenight before thelectures on the next day: find the topics of interest from the materials obtained after registration and mark the time and sessions.There are so many interesting and important topics and this is really a tough decision as sometimes I have to change to a different session during the midway of a lecture.

The topics in this year are similar to those in previous years and can be categorized into male & female infertility, Oocyte/embryo freezing, PGD & PGS, Endometriosis, Ovarian stimulation, PCOS, Stem cells, Embryo development & implantation, Ethics & law etc. The conclusions of those related to laboratory are as follows:
  1. Instead of slow-freezing, vitrification has become the oocyte and embryo cryopreservation method of choice in recent years.
     
  2. There is more evidence supports the beneficial effect of blastocyst culture under hypoxia (5% O2) conditions.
     
  3. It has recently been reported the integration of time-lapse imaging system in monitoring the embryos in culture, as well as an aid to identify the embryo(s) with the highest implantation potential.

Another topic is the correlation between biomarkers and embryo development. Single embryo transfer is common in Europe, however, recent studies have revealed that morphological evaluationfor embryo quality is insufficient for embryo selection, more precise biomarkers have been developed for single embryo selection in IVF.

There were 6 articles published in a lecture on novel embryonic markers on June 28th:
  1. Quantification of oocyte quality through respiration patterns correlates oxygen consumption with fertilization and subsequent implantation :A study in IVI, the largest assisted reproduction center in Spain, reported the application of oxygen consumption (OC) rate as a quality marker for human oocyte competence. Differences in the measured OC rates were found depending on different gonadotropins used in the stimulation, as well as on different serum E2 levels; High OC rates indicate good quality of oocytes and were found in oocytes that underwent normal fertilization as well as high implantation rate. High OC has often been regarded as a good indicator for metabolic activity and normal development of the oocyte.
     
  2. Near-infrared (NIR) analysis of day 5 embryo culture media from cohorts of patients’ embryos:Researchers from Sidney IVF, Australia, reported the application of near-infrared (NIR) (ViaMetrics-ETM) analysis of day 5 blastocyst culture media to generate a viability score of the embryo, with a specific aim to serve as an adjunct to morphology in improving the identification of the most viable embryo for single embryo transfer.This is another report after the study in Yale University to demonstrate the clinical feasibility of non-invasive metabolic profiling of embryo culture media to assess embryo viability in IVF.
     
  3. Subcellular dynamics of the maternal survival factor BCL2L10 in human pre implantation embryos:Researchers in the IVF Center of the Hospital Woman-Mother-Child in Lyon, France, reported detection of BCL2L10, an anti-apoptotic factor known to be expressed in oocytes, in preimplantation embryos at least until the blastocyst stage, but the mitochondrial expression disappeared in arrested, degenerating, or apoptotic embryos. Based on the fact that BCL2L10 is an anti-apoptotic factor, the expression of BCL2L10 may indicate the activity of oocytes and embryos.
     
  4. Identification of possible biomarkers of embryo viability in the human embryonic secretome: preliminary results:Researchers in the Assisted Fertilization Center, Sao Paulo, Brazil, identified Jumonji (JARID2) as one of the secreted proteins in embryo culture media of the positive-pregnancy group viaNanoUPLC (nano ultra-high pressure chromatography) and MS (mass spectrometer). Jumonji is a nuclear protein associated with cardiovascular, CNS, and liver development in murine embryos, and is associated with negative regulation of cell proliferation. In addition, in the embryo culture media from the negative-pregnancy group, they identified TSGA10 (Testis-specific gene 10 protein), a protein enhances cell division, just opposite to Jumonji. The existence of Jumonji in the secretome may serve as an adjunct to morphology in the selection of embryo for transfer.
     
  5. The number of infiltrating leukocytes in follicular fluid could be used as a novel marker to predict the developmental competence of mature oocytes:Researchers in the Kyono ART clinic, Sendai, Japan, found an increase of polymorphonuclear leukocyte counts in follicular fluid associated with blastocyst formation of oocyte. Since ovulatory follicles become inflamed has been supported by previous studies, ovulation may be controlled with a large variety of cytokines and chemokines which accelerate polymorphonuclear leukocyte infiltration, and which in turn may be used as a novel marker for better oocyte and embryo selection.
     
  6. Gene expression of hormones and hormone receptors and growth factors and receptors in 8-Cell human embryos - their role in early embryonic development:Researchers in General Hospital of Athens, Athens University Medical School, Greece, carried out microarray studies in 8-cell stage embryos and embryonic stem cells. It is generallyagreed the genome activation in the 8-cell stage embryos, and erroneous gene activation will lead to failure in the morula development. In this study, the authors reported in 8-cell blastomeres the overexpression of some nuclear receptors, transcription activators and some conserved hormones, but not their receptors, and insufficient in some growth factors, suggesting a lack of autocrine hormone or growth factor signaling.

Albeit there is only a few papers discussing biomarkersin the conference this year, there are more and more studies providing more reliable results of embryo quality assessment through the measurement of viability score with NIR mass spectrometer analysis of the embryo culture medium. On the other hand, the analysis of oxygen consumption in the embryo culture medium is also a good point and noteworthy for subsequent development and marketing performance. Non-invasive biomarkers have tremendous potential and we can foresee more development in the future and biomarkers as novel indicators of embryo quality for transfer.

In addition, manufacturers in the venue have launched a variety of Time-lapse imaging systems, which can serve as a real-time monitor for embryo, as well as for image recording and analysis. Based on the fact that there are already some preliminary results released, it could also be a future trend in embryo selection.