IMBA Group Leader Nicolas Rivron was awarded the Grand Prix Scientifique Charles Defforey. The recognition, awarded by the French Academy of Sciences and the Institut de France, supports high-level basic research, and is funded by the Charles Defforey Foundation.
Human early pregnancy involves an unusually close interaction between the embryo and the uterus. While this intimate connection allows for efficient exchange of nutrients and gases—thought to have supported the evolution of larger fetuses with larger brains—it also makes early pregnancy more fragile, representing an evolutionary trade-off. For instance, the likelihood of pregnancy per cycle in humans is around 30%, with a high rate of failure due to unsuccessful embryo implantation, especially when compared to closely related primates. In addition, suboptimal conditions during early pregnancy can have lasting consequences on health, including developmental issues such as heart defects that increase disease risk later in life.
To investigate the vulnerabilities of human pregnancy, Nicolas Rivron’s lab uses stem cells to model early development and implantation of mouse and human embryos in a uterine-like environment. The team studies how embryonic cells organize themselves and which genetic factors—such as regulatory DNA regions that time cellular behaviors like adhesion and migration into the uterus—contribute to the success or failure of early pregnancy.
Nicolas Rivron studied engineering in France before joining the R&D department of the biotech company Medtronic in the United States. He completed his PhD in 2010 in the Netherlands, focusing on vascular self-organization and tissue engineering, and soon after established his own research group affiliated to Maastricht University and the Hubrecht Institute. In 2018, his lab generated the first complete model of early embryos—blastocysts—formed entirely from mouse stem cells, a breakthrough called ‘blastoid’ that attracted international attention. Since 2019, he has been a group leader at IMBA. There, he extended this work by creating human blastoids mimicking day-7 human embryos, which contain all the cell types required to form the organism and can be combined, in the lab, with uterine organoids.
Rivron’s research has been recognized with awards from the European Research Council (ERC) and the Human Frontier Science Program and funded by the FWF Austrian Fund and the Austrian Academy of Sciences. In collaboration with former postdoctoral researcher Alok Javali and Peter Greiner, former Senior Vice President of Merck’s Global Head Fertility Franchise, he co-founded the biotech company dawn-bio, which is developing therapeutics to support healthy early pregnancy. Alongside his scientific work, Nicolas Rivron has actively contributed to building ethical frameworks for the responsible and justified use of embryo models. He has constantly worked with ethicists, philosophers, and legal experts, including within the International Society for Stem Cell Research (ISSCR) and as a founding member of the ethics committee of the European Molecular Biology Laboratory (EMBL). These efforts aim at regulating the research but also to foster public understanding by promoting an accurate and realistic view of modern human embryology, helping to ensure that scientific progress is accompanied by transparency and societal trust.
Every year, the Charles Defforey Grand Prix Scientifique is awarded by the Institut de France on the recommendation of the French Academy of Sciences. A jury composed primarily of members from the biology sections of the Académie des sciences selects a laureate whose work advances a specific field of scientific research. The prize includes a total fund of €400,000, with 90% allocated to research support and 10% awarded personally to the lead scientist in recognition of their individual contribution.