Safe, Simple, Secure and Effective Human Blastocyst Vitrification: Quality Control Factors that Optimize Success
Vitrification (VTF) is the single most impactful assisted reproductive technology in the IVF industry since the development of intracytoplasmic sperm injection (ICSI). Today, we faithfully cryopreserve blastocysts without regard to possible loss. We have had to re-educate ourselves, and our infertility patients, that fresh ET is no longer better than vitrified ET cycles, especially in combination with blastocyst biopsying and preimplantation genetic screening. Our ART lab is now able to routinely attain implantation rates in excess of 75% transferring single vitrified-warmed “euploid” blastocysts, independent of patient age. All of this, following 100% embryo recovery and a >99.5% survival rates of biopsied blastocysts using our non-commercial microSecure (μS)-VTF system and a glycerol/EG based, non-DMSO, metastable VTF solution (Innovative Cryo Enterprises, NJ, USA). Clinical VTF evolved slowly, with interests and acceptance being commercially driven by the development of unique VTF devices, safer solutions, and the misconception that ultra-rapid cooling in an “open” system was a necessity to optimizing VTF success. The dogma surrounding the importance of cooling rates has led to unsafe practices subject to excessive technical variation, and risky modifications to create closed storage devices. In the beginning, the financial push to create VTF devices in the marketplace was generally done with disregard to important quality control factors (e.g., ease of use, repeatability, reliability, labeling security, storage safety). Those with a firm understanding of cryobiological principles have always known that warming rate was the most important factor determining VTF survival. Furthermore, embryos are more cryotolerant of high molar VTF solutions than we have been led to believe. Like other aseptic closed VTF systems (e.g., Vitrisafe, HSV) effectively used in reproductive medicine, μS-VTF has proven that it can achieve the highest quality outcomes with unparalleled attention to QC details often lacking in commercialized VTF devices.
Dr. Mitchel C. Schiewe (Shee-we), is an Applied Comparative Reproductive Physiologist with an extensive research background in the application of Assisted Reproductive Technologies in the fields of Embryology and Andrology, involving more than 35+ different species. With a formal Animal Science background (B.S., UC Davis, 1981; M.S., LSU, 1983), he became a Research Associate of the Smithsonian Institution’s National Zoological Park (NZP) to help develop an embryo research program for nondomestic species throughout the 1980’s. He completed his doctorate in Physiology at the Uniformed Services University of the Health Sciences (USUHS, 1989) in Bethesda, MD and was a guest scientist at the National Institutes of Health (NIH) and NZP. Dr. Schiewe has conducted diverse, pioneering research, which has earned him 3 international research awards. He has worked in the field of human ART since 1992, and today, his Ovation Fertility Lab in Newport Beach has achieved some of the highest implantation rates in the world, attributed in part to extensive QC practices and his development of a highly effective aseptic closed vitrification system (microSecure-VTF) using non-DMSO metastable VTF solutions. In recent years, their comprehensive application of blastocyst biopsying/PGS, VTF-ALL cycles and an amazing team of Embryologists and Physicians.