The Frozen Embryo Transfer (FET) — in German Kryotransfer — is the embryo transfer of a previously cryopreserved and thawed embryo.
In Europe already 368,000 cycles in 2021 (ESHRE Focus on Reproduction); frequently carried out as a single-embryo transfer. It presupposes that the embryo was previously cryopreserved — and thus FET structurally continues the production of surplus embryos.
Ontological Classification
- is subclass of: embryo transfer
- presupposes: cryopreservation — and inherits its verdict along the path of presupposition
Personal-Ontological Assessment
The embryo introduced through FET is, from fertilization onward, a complete human person with full ontological dignity. The cryopreservation was a state, not a change of essence.
This decides nothing about the procedure itself. Frozen embryo transfer constructively presupposes cryopreservation, which the ontology of personhood carries as a case of practical forgetfulness of the person: the life of a person is placed in a state of suspension whose duration she does not determine and whose end is uncertain. Presupposed further is in vitro fertilization, carried by way of artificial fertilization as an intrinsically evil act.
The evaluation therefore reaches frozen embryo transfer along the path of presupposition, not by inheritance. This is no trifle for judging the individual case: where an embryo already exists and is frozen, transfer is the only course of action that opens a future to him, and is to that extent judged differently from the production that brought him into that state. What stands objected to is the way there, not the reception of what already exists — a child who comes into the world in this way is to be received as a gift like any other.
Sources: Research status 25 April 2026.
Further sources:
- ESHRE EIM Consortium (2024): ART in Europe, 2021: preliminary results. Human Reproduction 39, Supplement 1, deae108.136 (368,464 FET cycles in 2021).
- Roque, M. et al. (2019): Fresh versus elective frozen embryo transfer in IVF/ICSI cycles: a systematic review and meta-analysis of reproductive outcomes. Human Reproduction Update 25(1): 2–14.
- Maheshwari, A. et al. (2022): Elective freezing of embryos versus fresh embryo transfer in IVF: a multicentre randomised controlled trial in the UK (E-Freeze). Human Reproduction 37(3): 476–487.
- Wennerholm, U. B. & Bergh, C. (2020): Perinatal outcomes of children born after frozen-thawed embryo transfer: a Nordic cohort study. Human Reproduction Update 26(2): 159–176.