This conference hosted by the BMBF takes up the statement of the National Academy of Sciences Leopoldina "Re-evaluating of the protection of in vitro embryos in Germany[1] " (2021) and invites scientists to reflect on the topic from scientific, ethical and legal perspectives.
Research on and with early human embryos is prohibited in Germany by the Embryo Protection Act (ESchG), which has been in force since 1990, but is permitted within narrow limits in many other countries. Research on and with human embryonic stem cells in Germany is also only possible under strict conditions within the framework of the Stem Cell Act (StZG). Since several decades a wide range of novel research has already been legally carried out internationally, whose results have a huge impact on medical research and possible treatments. Scientists hope to employ this new knowledge to develop effective therapies for currently incurable diseases and common diseases such as diabetes, Parkinson's, Alzheimer's, stroke or heart attack. The scientific community also hopes that research with early embryos will shed light on how the causes of unwanted childlessness, miscarriages and premature births and genetic diseases in children can be prevented or better treated.
The conference is intended to highlight in particular the current scientific possibilities and perspectives of research with early human embryos for the various research areas in medicine and to relate them to the legal framework in Germany. The BMBF sees this as an impulse for a broad-based discourse that addresses concrete research needs and at the same time considering legal and ethical concerns.
The statement of the National Academy of Sciences Leopoldina, published in 2021 on the re-evaluation the protection of in vitro embryos in Germany, has identified significant and high-priority research goals that are being pursued abroad. To address these high-priority goals, human embryos and a clarification of the use of human embryos are needed. These research goals include:
Human embryos that are produced in the course of an in vitro fertilisation treatment, but are not used directly for reproductive purposes within a treatment cycle, can be cryopreserved, i.e.frozen. Thus, they can be used for a later fertility treatment if necessary.
If a couple declares the fertility treatment to be terminated, these stored embryos are referred to as "orphaned" or "surplus". Currently, couples in Germany have the choice of "discarding" the surplus embryos, i.e. having them destroyed, or donating them for adoption. Embryo adoption has so far been the exception in Germany.
The current German coalition agreement envisages allowing elective single embryo transfer (eSET) in the case of in vitro fertilisation within the framework of reproductive self-determination. The eSET method reduces multiple pregnancies and is therefore associated with significantly fewer risks during pregnancy for the expectant mother and the child. With the eSET method, several eggs are fertilised, but only the best developing embryo is selected for transfer into the uterus. This results in “surplus” embryos.
It can be assumed that in the future an increasing number of embryos will be created that are no longer to be used for fertility treatment. These embryos that are not transferred are cryopreserved, i.e. frozen. After completion of the fertility treatment, a decision has to be made on how to proceed with the “surplus” embryos.
Embryo research, which is permitted in several countries under strict conditions, provides important findings that are highly significant in the therapy of common diseases (e.g. diabetes, arthrosis, heart attack, stroke, cancer). Above all the field of regenerative and personalised medicine as well as therapy options for hereditary diseases benefit from the research results.
At present, a couple in Germany has the choice of "discarding" the “surplus” embryos, i.e. having them destroyed, or giving them up for adoption. Embryo adoption has so far been the exception in Germany. Currently, it is not possible in Germany to donate “surplus” embryos for research and research on human embryos is prohibited. Likewise, researchers in Germany are prohibited from participating in corresponding projects abroad, even if the research is legal there.
The National Academy of Sciences Leopoldina therefore recommends that research on “surplus” embryos in vitro shall be re-evaluated, so that the accordance with international ethical standards and the legal framework will be discussed anew. This should exclusively apply to high-priority research objectives, which, in accordance with the Leopoldina's statement, will be reviewed by a specially created committee. Likewise, the derivation of human embryonic stem cells should be made possible for high-level research objectives, including potential therapeutic uses.
Research involving human embryos is generally prohibited under the Embryo Protection Act (ESchG). If German researchers participate in international research on or with human embryos (even if it is legal abroad), they may be subject to criminal prosecution if the research is conducted, financed or otherwise supported from Germany.
The creation of embryos or the derivation of stem cells from existing embryos for research purposes is prohibited in Germany.
Research with human embryonic stem cells (hES cells) is only permitted in Germany under the strict conditions of the Stem Cell Act (StZG). Research with hES cells must be approved by the Robert Koch Institute (RKI) based on a vote by the Central Ethics Committee for Stem Cell Research (ZES). Only hES cells that were obtained legally abroad before a fixed cut-off date (01.05.2007) may be used. They may only be used for high-level research purposes, but not for clinical applications (so-called research proviso).
Human embryonic stem cells are cells, whose fate has not yet been determined and which can differentiate into any of the more than 200 cell types of the body. They are pluripotent. First, they differentiate into precursor cells that later form specialised tissues (e.g. skin, liver, blood, nerve cells). In contrast to the fertilised egg, embryonic stem cells are not totipotent; accordingly, embryonic stem cells cannot develop independently into a complete human organism.
Embryonic stem cells (ES cells) are derived from the blastocyst, a very early stage of the embryo. The blastocyst stage consists of about 60 to 100 cells. Solely very few cells of the blastocyst (only those of the inner cell mass) are suitable for generating ES cell lines.
In addition to embryonic stem cells (ES cells), pluripotent cells, from which different tissue types can be formed, can also be generated from mature, i.e. adult cells (e.g. skin cells) since 2012. In this process, cells are reverted to an early embryonic state in vitro by pre-treatment with certain transcription factors. These "reprogrammed" cells are called induced pluripotent stem cells (iPS).
In principle, both types of stem cells (ES and iPS) are used in research, depending on the specific research question. Different goals are pursued in research:
A primary goal of basic research is to investigate the molecular mechanisms responsible for the specialisation, proliferation and organisation of cells into more complex structures (e.g. organs) and thus for the development of the embryo. This research provides a better understanding of the origin of disorders in cell development and organs, and thus also diseases. This knowledge can help in the development of new and better treatment options in the future.
In addition, stem cell research pursues the goal of developping diseases models in the laboratory in order to explore the origin and courses of genetic diseases and to create the knowledge base for new therapeutic methods.