What the HFEA Requires for Embryo Storage in Liquid Nitrogen - A Practical Overview for Clinic Managers

If you manage or work in an HFEA-licensed IVF clinic, embryo storage is not just a laboratory function. It is a regulated clinical activity with specific requirements that apply from the moment an embryo enters Cryostorage to the moment it is used in treatment or disposed of in accordance with the patient's consent.

This overview covers the practical requirements most relevant to clinic managers and quality teams.

The HFEA Code of Practice requires that all embryos stored in licensed clinics are clearly identified and traceable at all times. Every storage straw must be labelled with patient identification before entering storage using cryogenic-grade labelling that will survive years at minus 196 degrees Celsius. Standard adhesive labels will fail at these temperatures. The identification system must allow unambiguous identification of each straw at any point during the storage period.

Storage must be in appropriately maintained liquid nitrogen vessels with continuous monitoring. The Code of Practice does not prescribe specific vessel types but requires that equipment is fit for purpose, properly maintained and subject to documented monitoring procedures. Continuous liquid nitrogen level monitoring with audible and remote alarms is the expected standard. Out-of-hours coverage must be in place with a clear escalation procedure for alarm events.

The standard consent-based storage period is 10 years. Extensions to up to 55 years are permitted in cases of premature infertility caused by medical treatment such as chemotherapy. Storage beyond the consent period is not permitted without renewed consent, and clinics must have robust systems for managing consent renewals and ensuring no samples remain in storage beyond their permitted period without appropriate documentation.

Inside the storage vessel, embryos are held in CBS embryo straws within CBS Daisy Goblets and canisters. This container hierarchy must be reflected in your laboratory's sample management records.

Full guide at cryolab.co.uk/how-to-store-embryos-in-liquid-nitrogen