Human Reproductive Cell Cryopreservation, Storage, Handling, and Transport: Risks and Risk Management

Abstract

Millions of human oocytes and embryos are stored in thousands of locations across the globe. This inventory continues to grow as cryopreservation becomes more successful and more widely applied. The results of studies assessing pregnancy and neonatal outcomes following frozen embryo transfer (FET) have been encouraging, showing lower incidences of small for gestational age neonates and preterm birth compared with fresh transfers. However, many of these studies have also shown that the odds of large for gestational age births and macrosomia are higher after FET. The origin of these conditions remains unclear. Cryostorage presents many potential risks to the cryopreserved cells/tissues, including loss of viability and contamination, but risks are faced also by care providers—for example, injury and financial liability—and by patients—for example, accidental loss of their reproductive tissues, the burden of embryos they no longer wish to use and failing to meet their contractual obligations. Studies are urgently needed to explore and understand all dimensions of cryostorage to help ART clinics develop effective strategies to manage associated risks. The future of cryostorage, as for many other areas of ART and medicine, is automation.

Considerations on staffing levels for a modern assisted reproductive laboratory

“…The programme involves COCs retrieval from a donor, insemination with sperm from the recipient's partner, fertilization, in vitro culture, and embryo transfer to the recipient's uterine cavity. In case of logistical difficulties or lack of donors, oocytes can be collected and vitrified, stored in liquid nitrogen and carefully transported to another IVF unit, located in another part of the country or abroad (Alikani & Parmegiani, 2018). This led to the establishment of egg-banks for the use of vitrified-warmed donor oocytes, located abroad and shipped to the recipient region.…”

Storage, transport, and disposition of gametes and embryos: legal issues and practical considerations

“…Where cryopreservation is routine, fertility clinics are cast as ''keepers'' of material that is full of hope and fraught with risks. Some of these risks include storage management, reduced or lost viability of specimens, rejection by gametes donors, and even contamination (6), and the associated costs. However, there are resources to assist in policy development to optimize the storage dilemma and reduce potential liabilities.…”

“…Although commercial transport websites imply that moving embryos is relatively risk free (36,37), recent studies report that methods of shipment and types of transportation matter. Liquid nitrogen vapor containers or ''dry shippers'' (cryotanks filled with liquid nitrogen that is absorbed into porous interior packing material) are commonly preferred for air transport, whereas liquid nitrogen-filled tanks are more often seen in shorter, landbased travel because of the specific requirements and risks of each mode of transport (6). Damage to vitrified oocytes has been reported from factors such as vibration/movement, increased temperature, air pressure, and horizontal tank positioning during transport (38).…”

“…Fast forward another decade, and reproductive medicine achieved and accepted oocyte freezing as another tool to enhance fertility treatment. Today, improved processes of cryopreservation (or ''freezing'' as it is commonly known) of human sperm, oocytes, and embryos, using vitrification to reduce freezing time and improve survival rates (4), and better culture systems that inte-grate highly complex media, environmental controls, and technical equipment (5), have become a fundamental part of providing assisted reproductive technology (ART) procedures to patients worldwide (6).…”

A Multi-Center Evaluation of a Novel IVF Cryostorage Device in an Active Clinical Setting

“…There is increasing demand for the cryostorage of human reproductive specimens [1][2][3][4][5][6][7][8][9][10][11][12]. Human reproductive specimen cryostorage handling remains intensely manual [13].…”