History of Dr. Kuwayama and his revolutionary invention that brought hopes to women in the world

The origin of his passion for his research

While having a title of CEO, Dr. Kuwayamaʼs life as a researcher has been longer than 30 years. His passion for research started when he was in the 6th grade. When he looked at water through a little microscope his grandfather bought for him, he found this fascinating world where he observed a lot of microorganisms. He was very excited to see a transparent daphnia giving birth to many of its babies, and since then he has been fascinated to this “micro-world.” In university, liking animals and creatures, he studied embryology in veterinary medicine. One day, he encountered a book introducing embryos of cows and was shocked, “eggs even though mammals!?” This made him want to do research on embryos, and he started to work for one of few companies that dealt with embryos back then. For the first year of working at this company, he could not do any research due to the training period, and he had a tough time suppressing his urge to do the research. However, when he heard the news of the successful In Vitro Fertilization using cowsʼ embryos, he could not stop his excitement. He formed a team for In Vitro Fertilization and started to do the research on cowsʼ embryos. Later, he succeeded in the cryopreservation of cowsʼ embryos and oocytes with the new technology of vitrification for the first time in the world. Since then, he has been inventing new technologies for In Vitro Fertilization and In Vitro Culture in the reproductive industry.

The turning point

In 1999, Dr. Kuwayama met a 47-year-old lady that had been receiving the treatments for infertility for a long period. When he saw her crying and being exhausted after repeating unsuccessful IVF, he could not help but imagine the harsh days she had been going through. This led him to a thought, “no matter how many times I succeed in inventing new reproductive engineering technologies in veterinary medicine, those technologies are not applied to humans in the medicine field. If I donʼt do it, people like her are never going to be treated and finally be happy.” The next day, he quitted his company and jumped into the world of reproductive medicine. As he saw many patients that were older or were severely infertile with the last hope of having a baby, he thought, “I have to do this as soon as possible,” and this feeling intensified every day. Though the subjects changed from cattle to humans, he utilized his knowledge he had obtained and devoted himself to his research with two big themes, cryopreservation and rejuvenation of embryos. While he underwent a tough time starting his research from scratch, he kept telling himself that inventions involved in failures and kept trying over again, which allowed him to achieve the application of cryopreservation of human embryos for the first time in the world within 2 months.

Reproductive medicine revolution for diminishing
the inequality between men and women

In 2000, with a slogan “deliver the cutting-edge oocytes cryopreserve technology, as quick as possible, to as many patients as possible,” Dr. Kuwayama integrated the cryopreservation technologies he had previously achieved and developed a kit for cryopreservation of oocytes and embryos. This kit brought a good success rate when followed by the appropriate procedures. This kit was utilized in 50 countries for more than 1,000,000 cases, and it captured the worldʼs attention. With this, patients that had to give up their babies for reasons, such as infertility and cancer, did not have to suffer anymore. Dr. Kuwayama said, “In the current society, there are women that cannot have a baby due to the side effects of treatments for cancer and women that give up their career to have a baby. I wanted to bring a revolution in order to diminish the inequality relating to gender like this.” He hoped that women would not have this disadvantage because of their gender and hoped that women that hoped to receive the treatment would be able to do so.

Inventing the innovative technology “The Cryotec Method”

100% survival after thawing
Even with the Cryotop Method, many lives of oocytes and embryos were lost due to the lack of safety of the medium and the difficulty of the protocol. With the survival rate after thawing, the Cryotop Method was not satisfying as an applicative technology for treating human infertility. Also, this technology was sold at a very high price for a commercial purpose by people around, ignoring Dr. Kuwayama’s beliefs. After Dr. Kuwayama kept doing his research and improving the existing technology, he finally succeeded in inventing the innovative vitrification technology with the 100% survival rate in 2012. “I want to spread this most effective and the safest oocytes/embryos vitrification technology from Japan at a low price with the appropriate procedures, so that it will reach everyone in need all over the world.” He named this technology “The Cryotec Method” and called the relating products “Cryotech brand.” Last year, we started to provide this technology with the world for the purpose of leading patients to happiness, with the partners that had the same beliefs in 26 countries. He says, “when I see the patient, her husband, her family, and even friends being happy with the baby thought to be impossible to achieve, that moment and the emotions… this is what gives me motivation and keeps me going. Our challenge to bring happiness to people in need has not stopped. We are currently doing research on these followings: vitrification for human ovarian tissues which we succeeded in 2007 for the first time in the world, vitrification for sperms, an efficient system for in vitro maturity of oocytes, and the rejuvenation of older oocytes. Now we are striving to make a change in patients’ lives by providing these new reproductive medicine technologies. We want to give a hope in the lives of people that are suffering because of the very unfair reproductive problems.


REPROLIFE representative
Masashige Kuwayama

We set up the world’s largest center with bovine In Vitro technology under human reproductive medical technology (1989) and developed the world’s highest level technology with its core technology such as in vitro fertilization, in vitro culture, cryopreservation as its leader, has been leading the world.
In March 1999, after encountering an unhappy elderly infertile patient couple who cannot be saved, we decided to devote ourselves to the development of reproductive supplementary medical technology to cure patients who will not cure, and from the following month we will cast into the reproductive medical community. Since then, he is striving for development research and dissemination.
In May, 1999 we succeeded in commercializing the human ovum cryopreservation for the first time in the world and opened up the possibility of making a child after unmarried cancer female cancer treatment. In 2001 the egg bank was expelled from abroad in 2002, by the ovum preservation technology first in the US in 2003, first in South America in the year 2004, and the first baby in Europe in 2006. Last year in Japan’s egg bank, frozen ova from unmarried leukemia patients (after marriage) the world’s first healthy baby was born. In order to disseminate superior cryopreservation technology all over the world, we devised and developed a freezing method for human eggs and embryos that everyone can do, and through international conferences, workshops, field practical training sessions, Kuwayama’s cryopreservation method is now one million cases have been implemented in 50 countries and are widely used. Also, in order to solve the egg aging of elderly patients who do not currently have such a treatment, we intensively developed an egg cytoplasm replacement method which replaces the cytoplasm of aged eggs with young normal on the concept of organ transplantation. We have already obtained the world’s first success in animal experiments and are just waiting for clinical trials.
At the same time, we are working on ova, sperm and embryo manipulation, such as incubator and transport device for culturing embryos, isothermal clean bench for aseptically operating embryos, cold clean bench for low temperature treatment, hypoxic culture system using nitrogen in the atmosphere, various peripheral technologies related to culture, devising and developing peripherals.
Recently, designing the most efficient, low cost, clean human embryo dry incubator, worldwide sale of products has started.

Education Background / History

Education Hokkaido University Graduate Ph.D. (Reproductive Engineering)
1981 Joined Kyodo Feed Co., Ltd.
1986 Ministry of Agriculture and Fisheries Livestock Experiment Station (Embryonic Development Laboratory: Dr. Akira Hanada) Researcher
1989 Cow’s In Vitro technology is the largest center in the world, Livestock Improvement Corporation Bitech Center Set up and become leader
1992 Bovine ovum freezing preservation is the world’s first success with a new method called “vitrification method”
1994 Part-time lecturer at Tokyo Agricultural University (until 2000)
1995 Australian country visit study (University of Adelaide)
1996 Invitation research in Denmark (Royal Copenhagen University)
1997 Argentina (Visiting Professor, University of Buenos Aires)
1999 Kato Ladies’ Clinic Inaugural Representative Research Institute Inauguration Successful commercialization of cryopreservation using vitrification preservation method of human egg
2000 Develop egg cryopreservation kit
2003 Succeeded in nuclear transplantation of bovine egg cytoplasm (egg rejuvenation)
2005 Journal of Reproductive Bio-Medicine Online (Editor)
2006 The permanent director of the Japanese clinical embryologist conference
2007 Part time lecturer at Azabu University / Human ovary cryopreservation success
2008 Meiji University, Part-time lecturer, International Medical Welfare University
2009 Director of the International Natural Cycle Association
2010 Repro Supported Medical Research Center established
2011 Part time teacher at the University of Singapore
2014 The world’s first healthy baby is born in ovum cryopreservation of patients with malignant lymphoma
2015 Renamed company to Repro Life Co., Ltd.

Education History / History

  • International Society of Mild Approaches in Assisted Reproduction
  • International Embryo Transfer Society
  • American Society of Reproductive Medicine
  • Japan Fertilization Clinic Society
  • Japanese Society of Reproductive Medicine
  • Japan Society of Clinical Embryologists
  • Japan Cryogenic Bioengineering Society
  • Japan Cryogenic Medical Society
  • Japanese mammalian egg society


May 1988 Received Chairperson Prize for Livestock Improvement Corporation
December 1993 66th Azabu Veterinary Medical Association Award Winner

Academic achievement

Published papers Cryobiology, Reproduction, Theriogenology, RBM Online magazines etc. total 102


Cryopreservation method of early embryos, towards the birth of life: theory and practice of reproductive supplementary medical embryo culture,
Edited by the Japanese Mammal Ovum Society, egg cytoplasmic transplantation and nuclear transplantation in total of 30 or more in total

Conference presentation etc.

International Embryo Transfer Society, International Congress on Animal Reproduction,
American Society of Reproductive Medicine, Japan Infertility Society,
Japan Breeding Biology Association etc.,
350 or more in total