What Does Egg Freezing Actually Involve?

A step-by-step guide to the process — so you know what to expect

If you have decided to freeze your eggs, the process itself can feel daunting. Clinics often describe it as straightforward. The women who have actually been through it tend to describe it as more involved than they thought both physically and emotionally.

Both versions are true. Egg freezing is a well-established medical procedure, regarded by medical regulators as safe and routine since 2012. It is also a real medical event, one that takes time, money, and emotional energy.

This article walks you through what actually happens, from your first consultation to your recovery, so you can plan with realistic expectations rather than marketing-brochure ones. 

Before you read this — a gentle nudge

This article is about the practical process of egg freezing. It assumes you have already done some thinking about whether egg freezing is the right path for you. If you are still weighing that up, please start with our Considering Egg Freezing content and tool first they are designed to help you reflect on your motivations, your fertility picture, your finances, and the alternatives, before you step into the medical process. Coming back here once you have done that thinking will make this article a lot more useful.

1. The initial consultation

Most women begin with an initial consultation at a fertility clinic. This is your first chance to meet the medical team, share your history, and ask questions. There is usually a fee for this and often it has to be paid up-front before your start: clinics commonly charge between £150 and £395. 

A good initial consultation will cover:

• Your medical history — including any conditions like endometriosis, PCOS, autoimmune disease, family history of early menopause, or previous fertility treatment

• Your fertility goals — how many children you might hope to have, and roughly when

• A frank conversation about age — age at freezing is still the single biggest shorthand of success

A few questions worth asking:

• How many eggs would you suggest I aim to bank, given my age and ovarian reserve?

• How many cycles is that likely to take?

• What is your OHSS rate, and how do you reduce it?

• What is the full cost — from consultation through to year one freezing?

You should not feel rushed. The HFEA and the Advertising Standards Authority have raised joint concerns about pressure-tactic marketing in the fertility sector. A clinic that pushes you to decide quickly is a flag, not a feature.

2. Fertility testing

Before treatment, you will have a set of tests to assess your fertility picture. These help your clinic plan the right medication doses for you, and give you a more personalised sense of what to expect.

Standard tests include:

• AMH (Anti-Müllerian Hormone) — a blood test that estimates how many eggs are left in your reserve. It can be taken at any point in your cycle

• Antral Follicle Count (AFC) — a transvaginal ultrasound that physically counts the small follicles visible on your ovaries at the start of your cycle

• Other hormone blood tests — including FSH, LH, oestradiol, and thyroid function, to look at your wider hormonal picture

• Viral screening — UK clinics are required to test for HIV, hepatitis B and hepatitis C before storing eggs

• A pelvic ultrasound — to check the uterus and ovaries

What these tests can tell you: roughly how many eggs you might collect in a cycle, and what dose of medication is likely to work for you.

What they cannot tell you: whether your eggs are good quality, or whether you would get pregnant naturally.

3. Understanding your likely outcome from the procedure 

This is the part many clinics rush. We do not want to.

Once you have your results, the conversation should turn to what is realistic for you. Here is the broad shape:

• Age is the strongest factor. Egg quality declines gradually through your 30s and more sharply after 35. The HFEA states clearly that age at freezing has a much bigger impact on success than age at thaw.

• Egg quantity matters too. UK data show most women under 38 have around 7–14 eggs collected in a single cycle (HFEA). Numbers tend to be lower in older age groups or for women with low ovarian reserve.

• Egg quality cannot be measured visually. Freezing does not improve quality — it preserves what is there on that day.

• More eggs generally mean a better chance. A widely cited model from the Journal of Human Reproduction estimates that 20 frozen eggs at age 34 give roughly a 90% chance of at least one live birth; at 37, around 75%; at 42, around 37%. More recent UK research suggests 15 or more eggs offer the most encouraging outcomes irrespective of age at freezing.

A useful conversation should give you a realistic idea of how many cycles you might need, not just a single rosy number.

4. Creating your treatment plan

Once you and your doctor agree to proceed, the clinic will build a treatment plan around your test results and your menstrual cycle.

You should expect:

• A medication protocol — which drugs you will take, when, and how. Most UK protocols use injectable hormones over around 10–14 days.

• A timeline — typically 4 to 6 weeks of active treatment, with around 90–120 days from initial consultation through to retrieval (Egg Advisor guideline).

• Consent forms — UK clinics are legally required to take written consent for storage and future use of your eggs. You will be asked to think about questions you may not have considered yet, including what should happen to your eggs if you change your mind, become unwell, or die.  You might also want to consider your options for donating your eggs if you do not end up using them.

• Scheduling around your cycle — the start of stimulation is usually timed to the first few days of your period.

UK clinics licensed by the HFEA are required to offer counselling before, during and after treatment. We recommend you take this up — even if you feel fine. Decisions about fertility tend to surface emotions you didn't know you had.

5. Ovarian stimulation

This is the longest active phase of treatment. For around 10 to 14 days, you will give yourself daily hormone injections to encourage your ovaries to develop several follicles at once, rather than the single follicle they would in a natural cycle.

During stimulation, you will typically attend the clinic every 2–3 days for:

• Monitoring scans — to check how many follicles are growing and at what speed

• Blood tests — to monitor hormone levels, especially oestradiol

Common side effects, reported by both the HFEA and the Nuffield Council on Bioethics, include bloating, headaches, mood swings, breast tenderness, tiredness and bruising at injection sites. Some women find this phase manageable; others find it physically and emotionally taxing. Both are normal.

If you have PCOS or a high AMH, your clinic may need to adjust your protocol carefully because of higher OHSS risk (more on this in section 10).

6. The trigger injection

When your follicles are the right size, you will be given a “trigger” injection — a final hormone dose that tells the eggs to complete their maturation. The timing is precise: egg retrieval is usually scheduled around 36–38 hours later. 

This is the one injection you cannot afford to mistime. Clinics will give you very specific instructions, often for an evening dose. 

7. Egg collection

Egg retrieval is a short outpatient procedure, normally done under sedation or light general anaesthetic. The HFEA describes it like this: a fine needle is passed through the vaginal wall, guided by ultrasound, to draw eggs from each ovary into a small tube.

What to expect on the day:

• Arrive fasted, usually for around 6 hours beforehand

• The procedure itself takes around 15–30 minutes

• Recovery — you will wake up in a recovery room, usually within an hour

• Going home — you might need someone to help you home post anaesthesia 

• Aftermath — most women feel some cramping and have light spotting for a day or two

8. The freezing process

Eggs go straight from collection to the lab. There, embryologists assess them and identify which are mature.

Only mature eggs can be frozen. Immature eggs are usually discarded, although some clinics may attempt to mature them in the lab. This is one reason the number of eggs frozen is often slightly lower than the number retrieved.

Mature eggs are then vitrified — a fast-freezing technique using liquid nitrogen, which cools the egg so quickly that ice crystals do not form inside it. Vitrification has substantially improved egg freezing outcomes since older slow-freezing methods, and is now the global. 

Your eggs are then stored in liquid nitrogen tanks. In the UK, since 1 July 2022, eggs can be stored for up to 55 years, provided you renew your consent every 10 years (HFEA). Storage fees are usually charged annually. 

9. Recovery after retrieval

Most women feel well enough to return to light activity within 1–2 days, and to normal life within a week. But the first few days can be uncomfortable.

What is common:

• Bloating — your ovaries are still enlarged and may take a couple of weeks to settle

• Cramping or pelvic tenderness — usually managed with paracetamol (please ask your clinic before taking other pain relief)

• Light spotting — for a day or two

• Tiredness — give yourself permission to rest

When to seek help: contact your clinic urgently if you have severe abdominal pain, a swollen and painful stomach, persistent vomiting, shortness of breath, faintness, or noticeably reduced urine output. These can be signs of OHSS (HFEA).

10. Risks and complications

We have a fuller article on this in the Consideration phase, but here are the headlines that you should discuss with your clinic. The HFEA describes egg freezing as mostly very safe, but there are real risks worth understanding:

• OHSS (ovarian hyperstimulation syndrome) — happens when the ovaries respond too strongly to the medication. The HFEA reports around a third of women experience a mild form (managed at home). Around 1% develop a moderate or severe form. Severe OHSS is rare but can be serious.

• Poor response — sometimes the ovaries produce fewer eggs than hoped, even with the right medication

• No eggs retrieved — uncommon, but possible

• Cycle cancellation — some cycles are stopped before retrieval if your response is inadequate or unsafe

• Procedural risks of egg collection — infection, bleeding, or in rare cases injury to surrounding organs (HFEA)

• Emotional impact — disappointment, anxiety, hormonal mood changes, and a sense of loneliness are all reported in the research (Nuffield Council on Bioethics)

If a clinic glosses over these, ask them again. You deserve a frank answer.

11. Why one cycle may not be enough

This is one of the most under-told parts of the story.

Many women plan and budget for one cycle, then find that a second (or third) is recommended to bank a useful number of eggs. The reasons are usually one or more of:

• Age — older eggs mean more eggs are typically needed for the same chance of a future live birth

• Egg numbers per cycle — if you collect fewer eggs than hoped, the maths simply will not add up to a meaningful bank in one round

• Personal goals — if you would like the option of more than one child, more eggs are needed

• Financial implications — each cycle is its own retrieval fee, medication bill, and recovery period; storage is then paid annually for as long as your eggs are kept

The honest summary: please budget — financially, emotionally and practically — with the assumption that one cycle may not be enough. If it turns out to be, that is a bonus. If it is not, you will have planned for it.

What to do next

If you have read this far, you are already doing the work — taking the time to understand the process before deciding. That is the right place to start.

Whatever you choose, we hope this helps. You can use our Considering Egg Freezing tool to take stock of where you are, or book a one-to-one session with an Egg Advisor for a confidential conversation.

Egg Advisor is independent and does not provide medical advice. We share information based on official UK guidance (HFEA, NHS, Nuffield Council on Bioethics), peer-reviewed research, and the experience of our community. Any treatment decision should be discussed with a qualified clinician who knows your medical history.