Embryo freezing

Who it's for

• Anyone with spare embryos after IVF
• Couples preserving fertility before medical treatment
• 'Freeze-all' cycles after embryo testing or to reduce OHSS risk

Key facts

• Embryo freezing cycles rose from 1,900 in 2014 to 10,450 in 2024.
• Embryos created with a partner need both people's consent to use or keep – if you separate, either can withdraw consent.
• Storage up to 55 years, renewing consent every 10 years.

What happens

1. 1

   IVF cycle

   Stimulation, egg collection and fertilisation.

2. 2

   Freezing

   Good-quality embryos are vitrified, usually at day 5–6 (blastocyst).

3. 3

   Later use

   Thawed for a frozen embryo transfer when you're ready.

How long it takes: Part of an IVF cycle.

Success rates

• Frozen embryos from good-quality cycles have good survival and birth rates – see frozen embryo transfer.

Each clinic's published rates – compared with the UK average – are on its profile in the clinic finder.

Costs

Freezing is usually £685–£900 including the first year of storage, then £300–£450 a year.

NHS funding

• Freezing spare embryos is often included in NHS IVF; long-term storage may be time-limited or self-funded depending on area.

Risks and side effects

• Not all embryos survive thawing (most do with vitrification).