Safe Storage of Gametes and Embryos: No Time for Complacency

Abstract

Recent serious untoward incidents in the field of assisted reproduction have once again highlighted the need for vigilance and in particular improved risk management in relation to the cryopreservation of gametes and embryos. Despite increasing levels of regulation and the requirement to adhere to total quality management practices, catastrophic incidents such as the death of an employee or the loss of a freezer full of patient embryos or sperm continue to occur sufficiently frequently for the industry to be concerned and highlight the need to make practices considerably safer. Potential losses through litigation could be considerable if the gamete or embryo bank is found to be negligent and fails to provide the necessary resources and implement recognizable control measures, which may include suitable facilities with adequate ventilation and oxygen monitoring, competent staff, and an appropriate level of well-maintained equipment; round-the-clock emergency procedures, early warning systems to deal with a failing vessel; and contingency to mitigate losses within a failing vessel and validated procedures which are embedded into the organization which lead to a high-quality end product, for example, frozen embryo while permitting a safe system of work. Since cross-contamination incidents have occurred in other disciplines such as blood cryostorage, which have led to the transmission of viral disease, the biological safety of the end product also requires careful consideration despite the fact that no similar incident appears to have come to light in the field of reproductive medicine. Implementation of risk reduction measures may include screening for blood borne viruses and possibly bacterial infection, careful selection of appropriate packaging plastics, and consideration as to whether packaging is suitable for immersion in liquid nitrogen. If not, vapor phase storage may be considered as additional mitigation. In the light of recent events, centers should place risk management of their cryofacilities and service high on the agenda and ensure that it becomes integral to future objective setting and business planning.

Cryopreservation as a Key Element in the Successful Delivery of Cell-Based Therapies—A Review

“…For maximum stability in this respect samples should be stored in the vapor phase immediately above LN (below −150°C) or in an ultra-cold freezer at temperatures below −130°C ( 10 ). Storage in bulk LN (−196°C) should be avoided in clinical situations as there is a real risk of microbial contamination, particularly in vessels that are accessed regularly and have been in use for an extended period ( 172 – 174 ). Further, to avoid cross contamination samples should not be stored with others known to pose a potential contamination risk in this respect.…”

“…During cryostorage, care must also be taken not to warm other samples that may have to be moved to provide access to the material being located. Best practice will also employ alarms and continual temperature monitoring to prevent sample loss in the event of power failure or malfunction ( 172 , 177 , 178 ). Containers can be purchased with barcodes, or these, and other forms of identification, can be added as required.…”

“…It is important to note that because of the various contamination risks associated with LN-cooled equipment ( 172 – 174 ), the provider of the frozen therapy may have opted to use a LN-free controlled rate freezer for sample processing. If the storage, transport or recipient facilities revert to using LN-cooled containers then the hitherto clean cryochain will be compromised.…”

Out of the Freezer and into the Policy Fire: Quandaries in Reproductive Cryopreservation

“…7 Because no federal entity regulates the use of gamete and embryo cryopreservation, the onus of promulgating advisories to lead the field of assisted reproduction falls to professional societies. 7 Because no federal entity regulates the use of gamete and embryo cryopreservation, the onus of promulgating advisories to lead the field of assisted reproduction falls to professional societies.…”

“…In many of the published cases of cryopreserved gamete and embryo loss, the root cause analysis demonstrates a combination of equipment malfunction and human error. 7 Because no federal entity regulates the use of gamete and embryo cryopreservation, the onus of promulgating advisories to lead the field of assisted reproduction falls to professional societies. The American Society for Reproductive Medicine (ASRM) and the Society for Assisted Reproductive Technology published a guidance document in 2013 titled Mature Oocyte Cryopreservation: A Guideline.…”