Timing and clinic visits
Thawing and transfer are planned in a separate cycle, usually within 2–3 weeks.
← TreatmentsTreatments
Embryo freezing
Vitrification and storage of suitable embryos for potential future use.
Request a consultation
Ask about this treatment
Your details are used only to contact you.
On this page
Risks and limitations
Every medical procedure has possible risks and limitations. Personal risks and alternatives should be discussed before consent.
Who may be assessed?
- Suitable embryos remaining after transfer in an IVF cycle
- Cycles where freezing all embryos is considered medically appropriate
- A uterine lining not suitable for transfer in that cycle
- Health conditions requiring treatment to be postponed
- Couples who wish to store embryos for a future pregnancy
Treatment process
- 01
Embryo assessment
The embryos monitored in the laboratory are assessed to determine which are suitable for storage.
- 02
Vitrification
Suitable embryos are frozen by very rapid cooling, labelled and placed in the storage tank.
- 03
Storage
Embryos are kept under continuously monitored conditions. The storage period and conditions are confirmed to you in writing.
- 04
Preparation before transfer
In a later cycle the lining of the uterus is prepared, monitored by ultrasound.
- 05
Thawing and transfer
The embryo is thawed on the day of transfer and placed in the uterus. No egg collection and no anaesthesia are required.
Frequently asked questions
Does freezing harm the embryo?
Vitrification was developed specifically to prevent ice crystals forming. Even so, not every embryo behaves the same way after thawing; this is assessed on the day of thawing.
Is a thaw cycle easier?
Usually yes. Because there is no ovarian stimulation or egg collection, it requires less medication and fewer clinic visits.
How many embryos can be stored?
The number depends on how many embryos develop and are found suitable in that cycle. An exact figure cannot be given in advance.
What if I no longer wish to store them?
Ending storage requires your written consent. The process and conditions are explained in detail at your consultation.
Detailed information
Embryo freezing is the storage, by vitrification, of embryos obtained in an IVF cycle whose development is judged suitable. Vitrification is a very rapid cooling technique that prevents ice crystals forming inside the cell.
Why freeze embryos?
More than one embryo may develop in an IVF cycle. While one is transferred, the others can be stored — allowing you to continue later without a new cycle of ovarian stimulation. In some situations all embryos are frozen and the transfer is left to a later cycle; the reason for this is determined by your doctor.
How does thawing and transfer work?
A stored embryo is thawed and transferred in a cycle where the lining of the uterus has been prepared. There is no egg collection in that cycle, so it requires less medication and fewer clinic visits.
Storage period
Storage conditions, duration and the legal framework vary by country. The conditions that apply in your case are given to you in writing at the first consultation.
This page is for general information and does not replace an examination, a diagnosis or personal medical advice.
Related doctors
Ask about this treatment
Your details are used only to contact you.