What Happens to Unused Embryos?

The options for unused embryos in IVF: storage, donation, disposal, or future transfers. Understand the choices and UK regulations.

9/6/20254 min read

One of the lesser-talked-about parts of IVF is what happens to the embryos that aren’t transferred right away. Many people picture IVF as a straight line: stimulation, egg retrieval, fertilisation, transfer, pregnancy. But the reality is far more layered. Very often, more embryos are created than can be used in a single cycle. These are the unused embryos - and deciding their future can be just as complex and emotional as the treatment itself.

In the UK, embryos can legally be stored for up to 55 years if consent is renewed at set intervals. That long timeframe is designed to protect patient choice, but it also raises a deeply personal question: what do you want to do with them?

Why Do We End Up With Unused Embryos?

The IVF process aims to maximise your chances of pregnancy. Clinics usually fertilise multiple eggs because not every egg will mature, fertilise, or develop into a strong embryo. From this pool, one or sometimes two embryos are selected for transfer. The rest are frozen for possible future use.

Having unused embryos can be a blessing - they represent additional opportunities for pregnancy without needing to repeat the entire stimulation and egg collection process. But they can also feel like a burden, holding emotional weight that lingers long after treatment ends.

Option 1: Keeping Embryos in Storage

The most common choice is simply to keep embryos frozen. Storage gives you:

  • Flexibility for the future: if the first transfer doesn’t succeed, you have backup embryos ready.

  • Sibling pathways: many families return years later for another child.

  • Time to decide: you don’t have to choose immediately what to do.

Storage does, however, come with costs. UK clinics charge annual storage fees ranging from £200 - £400. You also need to keep contact details and consent forms up to date. If forms lapse, the clinic cannot legally store your embryos. This is one of the most overlooked risks - letters sent to an old address can, in time, lead to embryos being disposed of.

Option 2: Using Embryos for Future Transfers

If you’re still in treatment or want to try again later, your unused embryos can be thawed and transferred. This is called a frozen embryo transfer (FET).

Success rates for FETs are strong. In fact, many clinics report comparable or even slightly higher success rates compared with fresh transfers, partly because the body has had time to recover from the stimulation phase. For many families, children born years apart share the same cycle origin - embryos created on the same day, but transferred in different years.

Option 3: Donation to Another Patient

For some, the choice is to donate unused embryos to another couple or individual. This is one of the most generous, yet emotionally complex, paths.

  • The gift of life: it allows others who cannot produce viable embryos to have a chance at parenthood.

  • Legal framework: in the UK, donation is regulated by the Human Fertilisation and Embryology Authority (HFEA). Donor anonymity is limited: donor conceived children can request identifying information about their donor parents once they turn 18.

  • Emotional impact: donating embryos means accepting that your biological children may be raised in another family. Some find this empowering, others find it unsettling.

It’s worth noting that embryo donation isn’t as widely practised in the UK as egg or sperm donation, partly due to the extra layers of consent required from both partners.

Option 4: Donation to Research or Training

Unused embryos can also be donated for medical research or training. This option doesn’t result in a live birth but contributes to science in meaningful ways:

  • Research: embryos help scientists study early development, improve IVF success rates, and understand genetic conditions.

  • Training: embryologists and doctors learn advanced techniques using embryos that would otherwise be discarded.

Some parents find comfort in knowing that their embryos play a role in advancing medicine and helping future patients.

Option 5: Disposal

The final option is disposal. This means thawing embryos and allowing them to stop developing.

Clinics usually carry this out in the lab. Some allow patients to be present, others do not. For many, this is the hardest choice of all. It can feel like letting go of potential life, and people often wrestle with questions of morality, spirituality, or closure.

Rituals - whether symbolic, religious, or personal - can help. Some people choose to mark the moment privately with words, candles, or remembrance. Others prefer to let the clinic handle it quietly.

The Legal Framework in the UK

The UK has strict regulations around embryos, set by the HFEA (Human Fertilisation and Embryology Authority). The key points are:

  • Storage limit: up to 55 years if consent is renewed every 10 years (for medical reasons), otherwise 10 years is the standard limit.

  • Consent: both partners must agree. If one partner withdraws consent, embryos cannot be used or donated.

  • Donation rules: embryo recipients and donor-conceived children have legal rights to information.

  • Abandoned embryos: if contact is lost and forms lapse, clinics must dispose of embryos according to the law.

The Emotional Weight of Unused Embryos

The medical details are one thing, but the emotional dimension is another. For many people, embryos carry meaning far beyond the scientific. They may represent:

  • Hope: the chance of another child.

  • Loss: especially if treatment hasn’t worked.

  • Ethical dilemmas: what does it mean to donate, to destroy, to let go?

Couples don’t always agree, and these discussions can be fraught. Counselling is available through most clinics and is worth considering. Sometimes having a neutral space to explore your feelings makes the decision clearer.

Real Experiences

Some common stories patients share:

  • “We kept ours in storage for years because we couldn’t face the decision. Eventually, we donated them to research. It felt like the right way to honour them.”

  • “We donated to another family. It was a long process, but I like knowing our embryos gave someone else the joy of a child.”

  • “We had to let them go. It was painful, but we created a small ritual at home. It gave us closure.”

Each path carries its own kind of grief, hope, or meaning. There is no single “right” choice.

Questions to Ask Yourself

If you’re facing the decision, consider:

  • Do we want more children, or are we complete as a family?

  • How do we feel about biological siblings being raised by others?

  • Would donating to science feel meaningful or distressing?

  • How much do storage fees affect our decision?

  • Do both partners truly agree?

Unused embryos sit at the crossroads of science and emotion. They hold possibility, uncertainty, and sometimes heartache. Whether you choose to store, transfer, donate, or dispose of them, the decision is deeply personal.

Take your time. Talk with your partner. Ask your clinic for clear information. And most of all, give yourself grace - because whatever you decide, it will be the right choice for your circumstances, your family, and your heart.