Egg Freezing (Oocyte Cryopreservation) — How It Works, Benefits & Recovery — Procedure Guide, Recovery & Risks | MyMedicPlus

Egg freezing (oocyte cryopreservation) is a medically established fertility preservation technique in which a woman's eggs are stimulated with gonadotrophin hormones, retrieved from the ovaries, and preserved by vitrification — an ultra-rapid flash-freezing technique using cryoprotectants that prevents ice crystal formation inside the oocyte. Vitrification superseded the older slow-freezing method because it achieves 70–90% egg survival post-thaw compared to 50–60% with slow-freeze, dramatically improving cumulative live birth rates. When the woman is ready to attempt pregnancy, thawed eggs are fertilised by intracytoplasmic sperm injection (ICSI) and resulting embryos transferred to the uterus. The American Society for Reproductive Medicine (ASRM) removed the 'experimental' label from egg freezing in 2012 following sufficient evidence demonstrating equivalent pregnancy rates to fresh IVF cycles in women under 38. Egg freezing is performed at IVF clinics by reproductive endocrinologists and trained nursing teams. It is indicated for elective fertility preservation (social egg freezing), oncofertility preservation before gonadotoxic treatment, and medical conditions affecting ovarian reserve. Since the ASRM removed the 'experimental' label from oocyte cryopreservation in 2012, egg freezing has become mainstream: over 10,000 elective egg freezing cycles are performed annually in the UK, with the average age of women choosing elective freezing being 37 years.

Egg freezing is recommended for several distinct groups. Elective (social) fertility preservation: women aged 25–37 who wish to defer childbearing for personal, professional, or relationship reasons while preserving the option of using younger eggs in future. ASRM guidance notes that the best outcomes are achieved with eggs frozen before age 35, when egg quality and quantity are optimal. Medical oncofertility preservation: women facing gonadotoxic cancer treatments — alkylating chemotherapy agents (cyclophosphamide, BCNU), pelvic radiotherapy, or bilateral oophorectomy — that would permanently damage or eliminate ovarian reserve. Urgent egg freezing before chemotherapy is possible in a compressed 10–14 day stimulation cycle using random-start protocols. BRCA carriers: women with BRCA1 or BRCA2 mutations who plan risk-reducing salpingo-oophorectomy before age 40 benefit from prior oocyte banking. Premature ovarian insufficiency (POI): women with Turner syndrome mosaicism, fragile X pre-mutation, or autoimmune POI diagnosed early may bank eggs while ovarian reserve remains. Endometriosis patients with rapidly declining AMH levels are also candidates, given evidence that each surgical cystectomy reduces remaining ovarian reserve.

Egg freezing involves a 10–14 day stimulation phase followed by egg retrieval under IV sedation. Initial assessment: baseline ultrasound (antral follicle count, AFC) and blood tests (AMH, FSH, LH, oestradiol) assess ovarian reserve and predict response to stimulation. Stimulation protocol: self-administered subcutaneous injections of recombinant FSH (follitropin alfa or beta, 150–300 IU daily) and LH (or hMG) are started from day 2–3 of the menstrual cycle. The pituitary is suppressed by a GnRH antagonist (cetrorelix or ganirelix) from day 5–6 to prevent premature ovulation. Monitoring: serial transvaginal ultrasound scans (every 2–3 days) and blood oestradiol levels track follicle growth. When 2–3 follicles reach 18–20 mm, ovulation trigger is administered — hCG 10,000 IU for standard protocols, or GnRH agonist (buserelin) for high-responders at risk of OHSS. Egg retrieval: exactly 36 hours after triggering, transvaginal oocyte retrieval is performed under IV sedation. A 35-cm aspiration needle guides through the vaginal wall under continuous ultrasound visualisation to aspirate follicle contents from each ovary. Procedure takes 20–30 minutes. Embryologists immediately identify and evaluate oocytes; mature MII oocytes undergo vitrification using Irvine Scientific or Kitazato vitrification kits, then stored in liquid nitrogen cryotanks. Vitrification — ultra-rapid cryopreservation at –196°C — achieves post-thaw survival rates of 80–90% per egg.

Egg freezing provides women with reproductive autonomy — the ability to preserve reproductive potential at a younger biological age while deferring parenthood to a more suitable personal circumstance. Vitrification technology achieves 70–90% egg survival post-thaw, fertilisation rates of 70–80% per ICSI, and cumulative live birth rates of 40–60% for women who freeze 10–15 eggs before age 35. For cancer patients, egg freezing before gonadotoxic treatment completely protects fertility potential and substantially reduces the psychological impact of cancer treatment on future family planning. ESHRE and ASRM guidelines strongly recommend egg freezing as the standard of care for oncofertility preservation. The procedure does not deplete the natural egg supply — retrieved eggs are those which would have been naturally lost in that menstrual cycle. Eggs can be stored indefinitely in liquid nitrogen without deterioration (long-term stability confirmed in studies of eggs stored over 10 years). In India, egg freezing cost is approximately INR 80,000–1,50,000 (USD 1,000–1,800) per cycle including medications, compared to USD 10,000–15,000 in the USA. NABH/JCI-accredited IVF centres in India achieve international-standard success rates.

Ovarian hyperstimulation syndrome (OHSS) is the most significant risk of ovarian stimulation. Mild OHSS (bloating, pelvic discomfort, nausea) occurs in 20–33% of women. Moderate OHSS (abdominal distension, vomiting) in 3–6%. Severe OHSS (ascites, pleural effusion, haemoconcentration, thrombosis risk, renal impairment) occurs in 0.5–2% of cycles — requiring hospitalisation, IV fluids, and thromboprophylaxis. High-risk patients (high AFC, AMH over 3 ng/mL, polycystic ovarian morphology) are managed with lower stimulation doses, antagonist protocols, and GnRH agonist trigger (instead of hCG) with a freeze-all strategy. Egg retrieval procedural risks include bleeding (less than 1%), infection requiring antibiotics (1–2%), and injury to adjacent structures (bowel, bladder, blood vessels) in under 0.5%. Multiple pregnancy is a risk when thawed eggs are used — transferring single embryos (single embryo transfer, SET) essentially eliminates this. Emotional impact of the hormone treatment, monitoring visits, and procedural aspects can be significant; psychological support is an important component of care. Eggs retrieved may not all be mature or survive freezing and thawing — the number suitable for use may be fewer than retrieved.

Immediately after egg retrieval, the patient rests in the recovery area for 1–2 hours as IV sedation wears off. A responsible adult must accompany the patient home as driving is not permitted on the day of retrieval. Mild-to-moderate pelvic cramping, similar to period pain, is expected for 1–3 days and managed with paracetamol and ibuprofen. Bloating from the stimulated ovaries (which may be 3–5 times their normal size) persists for 5–10 days before resolving as oestrogen levels fall. Vaginal spotting for 1–3 days after retrieval is normal. Women with mild OHSS (bloating without vomiting) are managed at home with increased fluid intake, rest, and close monitoring by the clinic. Normal activities including light work resume within 1–3 days. Strenuous exercise is avoided for 5–10 days post-retrieval until ovarian size returns to normal. The menstrual period returns approximately 10–14 days after retrieval. Follow-up phone call or consultation at 1–2 weeks confirms recovery and storage confirmation. Egg storage costs, regulatory limits, and consent for future use are confirmed in writing at the time of storage.