The Egg Freezing Process Step by Step: From Consultation to Frozen

For most women, the mechanics of egg freezing are unclear until they are already in the middle of the process. What injections do I give myself? How often do I come in for monitoring? What happens to my eggs in the laboratory? What does the collection procedure actually involve? This step-by-step guide answers all of those questions — so you know exactly what to expect before you begin.

Step 1: Initial Consultation and Baseline Assessment

The process begins with a consultation — either in person or via video — to discuss your reasons for considering egg freezing, review your medical history, and order baseline investigations:

• AMH blood test: Measures ovarian reserve — can be done on any cycle day.
• Day 2 to 3 hormonal panel: FSH, LH, oestradiol — provides further reserve information.
• Transvaginal ultrasound: Antral follicle count (AFC) in both ovaries, assessment of the uterus and ovaries.

Based on AMH and AFC, your specialist will estimate the expected number of eggs per cycle, advise on the target number to freeze, and estimate how many cycles may be needed. This is the foundation of realistic planning.

If investigations are normal and you are ready to proceed, a stimulation cycle can begin in the next or following menstrual cycle.

Step 2: Pre-Cycle Preparation (Days 1 to 2 of Cycle)

Stimulation typically begins on day 2 or 3 of a natural menstrual period. In the day or two before, you will have a baseline ultrasound to confirm the ovaries are quiet (no dominant follicle or cyst from the previous cycle), the endometrium is thin, and the antral follicle count is appropriate.

If everything looks good, stimulation medications are started. Your clinic will walk you through subcutaneous injection technique — most women manage this confidently within 1 to 2 injections. The needles are very fine and the procedure is far less uncomfortable than most women expect.

Step 3: Ovarian Stimulation (Days 2 to 12 Approximately)

Gonadotrophin injections (FSH alone, or combined FSH + LH) are given once or twice daily for approximately 10 to 14 days. The dose is determined by your AMH, AFC, and body weight. Women with lower reserve start at higher doses; women with high reserve (or PCOS) start at lower doses to avoid over-response.

GnRH antagonist injections are typically added from day 5 to 6 of stimulation — these prevent premature ovulation (the LH surge) before egg collection is planned.

Monitoring ultrasounds are performed every 2 to 3 days throughout stimulation. Each ultrasound takes 10 to 15 minutes and measures the size of developing follicles in both ovaries. Blood oestradiol levels are checked alongside the ultrasound at key points to confirm follicle activity.

As follicles approach maturity (18 to 20 mm), the frequency of monitoring increases — every day or every other day. The total number of monitoring appointments is typically 4 to 5 across the stimulation period.

Step 4: Trigger Injection (Day 10 to 14 Approximately)

When the leading follicles reach 18 to 20 mm — the threshold for egg maturity — a trigger injection is given to complete the final maturation of the eggs inside the follicles. The trigger is timed precisely: egg collection is scheduled exactly 35 to 36 hours after the trigger.

Two types of trigger are used:

• hCG trigger: Standard for most patients. Predictable, well-established.
• GnRH agonist trigger: Used for women at high risk of OHSS (high AFC, high oestradiol, PCOS). Produces a more physiological LH surge, significantly reduces OHSS risk, and is the preferred trigger at Solo Clinic for at-risk patients.

Step 5: Egg Collection (Day 12 to 16 Approximately)

Egg collection (oocyte retrieval) is performed under sedation or light general anaesthesia — you will not be aware of or remember the procedure. A transvaginal ultrasound probe guides a fine needle through the vaginal wall into each follicle. The follicular fluid is aspirated and immediately examined by the embryologist under the microscope to identify eggs.

The procedure takes 20 to 30 minutes. You stay in the recovery area for 2 to 4 hours. Mild cramping and spotting are normal for 24 to 48 hours. Most women return to work the following day.

Approximately 70 to 80% of follicles yield a mature egg. If your ultrasound showed 14 follicles, expect approximately 10 to 12 eggs to be collected — of which perhaps 8 to 10 will be mature (MII) and suitable for vitrification.

Step 6: Vitrification — Flash Freezing Your Eggs

Mature eggs are identified, graded, and prepared for vitrification within 2 to 4 hours of collection. Vitrification is a ultra-rapid cryopreservation technique in which eggs are dehydrated, loaded with cryoprotectant solution, and plunged into liquid nitrogen at -196°C — the entire process taking less than a minute per egg.

The speed is critical. Older "slow freezing" methods allowed ice crystals to form inside cells, damaging the spindle apparatus that controls chromosome segregation. Vitrification is so fast that ice crystal formation does not occur — eggs are preserved in a glass-like (vitreous) state. Egg survival rates with vitrification at experienced centres are 85 to 95%, compared to 60 to 70% with slow freezing.

Your frozen eggs are then stored in clearly labelled cryostraws in liquid nitrogen tanks. They can remain in storage indefinitely — the cold provides complete biological suspension.

Step 7: Storage

After vitrification, your eggs are stored in secure cryogenic storage at the clinic. You will receive documentation of the number and quality of eggs stored. Annual storage fees apply — confirm these in writing before the cycle begins.

Frequently Asked Questions

Q1. Can I exercise during an egg freezing cycle?

Light exercise (walking, yoga) is generally fine during stimulation. High-impact exercise, heavy lifting, and activities that involve sudden twisting movements should be avoided once the ovaries become enlarged (from approximately day 6 of stimulation onward). Enlarged ovaries are at slightly elevated risk of torsion (twisting on their own stalk) with vigorous movement. Most women find they naturally reduce activity as they feel bloating increasing through stimulation.

Q2. Can I drink alcohol during stimulation?

Avoiding alcohol during the stimulation phase is recommended. Alcohol affects hormonal levels and cellular health — and as you are investing significantly in the quality of the eggs being produced, it is worth eliminating this variable for the 2-week stimulation period.

Q3. What happens if I develop OHSS?

Mild OHSS (bloating, mild discomfort, mild nausea) is common and resolves within a week with rest and hydration. Moderate OHSS requires close monitoring and sometimes drainage of abdominal fluid. Severe OHSS — significant fluid accumulation requiring hospitalisation — is rare, particularly with GnRH agonist trigger and appropriate protocol management. If you are at high risk (high AFC, high oestradiol, PCOS), your clinic should proactively use the agonist trigger and may recommend a freeze-all approach if severe OHSS develops.