Note: The ethical judgments on this page refer exclusively to the action — never to the person who performs it or is affected by it. Cf. Note on ethical judgments (German).
Cryopreservation is the freezing of biological material — in particular of embryos or gametes — at extremely low temperatures for later use. Today it is carried out predominantly as vitrification (flash-freezing in liquid nitrogen at −196 °C, without ice-crystal formation).
In the context of in vitro fertilization, surplus embryos are cryopreserved because several embryos are generated per cycle but only one or a few are transferred. After thawing, the embryos can be used for further embryo transfers (Frozen Embryo Transfer) or remain in indefinite storage (indefinite cryostorage).
Ontological classification
- is a subclass of: practical oblivion of the person
- has subclass: indefinite cryostorage
- prerequisite for: Frozen Embryo Transfer
Personal-ontological classification
In the cryopreservation of embryos, the human person is held for an indefinite time in a state of suspension — a state that does not do justice to the personhood and the ontological dignity of the embryo, because it halts the natural development and makes the person into an available object of a later decision.
The cryopreserved embryo remains a complete human person with full dignity. The dignity suffers no diminishment; what is problematic is the practice that subjects personhood to suspension.
Three pathways of use
From cryopreservation three pathways lead onward, each to be assessed differently:
- Later embryo transfer ( cryotransfer) — the embryo is thawed and introduced at its natural place of development. In personal-ontological terms the obvious pathway.
- Embryo donation — the embryo is passed on to third-party intended parents. Ambivalent, but the milder pathway compared to discarding.
- Embryo research utilization or discarding — a grave violation of the right to life (German).
The special case of indefinite cryostorage arises when none of these pathways is actively pursued.
Sources: Generated by querying the Personhood ontology. (Research as of 25 April 2026.)
Further sources:
- Congregation for the Doctrine of the Faith (2008): Instruction Dignitas Personae on Certain Bioethical Questions (8 December 2008), in particular no. 18 on cryopreservation.
- Human Fertilisation and Embryology Authority (HFEA) (2021): Fertility treatment 2019: trends and figures. hfea.gov.uk.
- Practice Committee of ASRM (2021): Disposition of unclaimed embryos. Fertility and Sterility 116(1): 48–53.
- Lyerly, A. D. et al. (2010): Fertility patients’ views about frozen embryo disposition: results of a multi-institutional U.S. survey. Fertility and Sterility 93(2): 499–509.