Yoshimasa Yokota

Gynecology/Obstetrics, Yokota Maternity Hospital
  • Yokota Maternity Hospital
  • Japan

About Yoshimasa Yokota

I have been running an obstetrics and gynecology clinic for over 40 years and in particular, ART for over 30 years and have contributed the community.

Recent Comments

Mar 08, 2021

Dear Editor,

I am very interested in your article “a review of best practices of rapid-cooling vitrification for oocytes and embryos: a committee opinion” on Fertil Steril 2021,115:305-309.


I hope it will be added one point my opinion.

You showed a first delivery after human blastocyst rapid cooling by Mukaida et al. 2001 on supplement table 1.  However, we already published the Hum Reprod 15:1802-3, 2000 (1) and Fertil Steril 75: 1027-29, 2001 (2). So, our publication was earlier than them.  Also, Stachecki JJ referred our paper in his publication (3) and another, Lucinda L, Veek referred our paper in her Atlas of Human Blastocysts book.


Today we widely used for general vitrification reagent which contained ethylene glycol/DMSO for human embryos cryopreservation. The application of this freezing agents to human embryo was epoch-making. Therefore, best of our knowledge, we believe that we used the first successful delivery baby from human blastocysts using ethylene glycol/DMSO on June 23, 2000 in the world.

We look forward to quoting our achievements at the next opportunity.



  • Yokota Y, Sato S, Yokota M, Ishikawa Y, Makita M, Asada T, Araki Y: Successful pregnancy following blastocyst vitrification: case report. Hum Reprod 2000; 15:1802-3
  • Yokota Y, Sato S, Yokota M, Yokota H, Araki Y: Birth of a healthy baby following vitrification of human blastocysts. Fertil Steril 2001; 75:1027-9.
  • Stachecki JJ, Garrisi J, Sabino S, Caetano JP, Wiemer KE, Cohen J. A new safe, simple and successful vitrification method for bovine and human blastocysts. Reprod Biomed Online 2008; 17:360-7.


Best regards.


Yoshimasa Yokota, M.D.

Yokota Maternity Hospital, 1-16-5, Shimokoide, Gunma 371-0031, Japan.

E-mail: aikoukai@olive.ocn.ne.jp