Egg Freezing (Oocyte Cryopreservation)

Egg survival rates after thawing with modern vitrification techniques are 90-97%. For women under 34 who freeze 10 mature eggs, the estimated live birth rate is 70-80%. For women 35-37 with 15-20 eggs, rates are 60-70%. Women 38-40 need 20-35 eggs for 40-50% success. Success depends primarily on age at freezing, not age when eggs are used—eggs frozen at 32 perform like 32-year-old eggs regardless of when used. Individual outcomes vary based on egg quality and other factors.

The recommended number depends on your age and family size goals. For one child, aim for 10-15 mature eggs. For two children, 20-25 eggs are recommended. Each additional child requires approximately 10 more eggs. Multiple cycles may be needed to bank sufficient eggs, especially for women over 35. Your fertility specialist will provide personalized recommendations based on your ovarian reserve assessment.

Eggs can be stored for decades in liquid nitrogen at -196°C. In the UK, storage is permitted for up to 55 years with consent renewal every 10 years. There is no evidence that storage duration affects egg quality or future pregnancy outcomes. Annual storage fees in Thailand range from $300-$600 USD. Eggs can be transported to other facilities internationally if needed.

The egg retrieval procedure is performed under IV sedation, so you will not feel pain during the procedure. During the 10-14 day stimulation phase, daily injections may cause minor discomfort, bloating, and mood changes. After retrieval, expect mild cramping similar to menstrual cramps for 1-3 days. Severe abdominal pain, fever, or heavy bleeding should be reported to your medical team immediately.

Egg freezing stores unfertilized eggs, requiring no partner or sperm donor at the time of freezing. Embryo freezing stores fertilized embryos, requiring sperm from a partner or donor. Egg freezing offers more flexibility for future family planning as you can choose your partner later. Embryo survival rates (95-99%) are slightly higher than egg survival (90-97%), but modern vitrification has significantly narrowed this gap. Egg ownership is simpler legally as a single owner.

Short flights are possible the day after retrieval if you feel well. Most patients can safely fly after 2-3 days. For long-haul flights over 4 hours, waiting 5-7 days is recommended. Optimal international travel timing is 7-14 days post-retrieval when ovaries have returned to normal size. Wear compression stockings, stay hydrated, and walk during flights. Your fertility team will provide clearance based on your individual recovery.

When ready to use your eggs, they are thawed in a specialized solution with 90-97% survival rate. ICSI (intracytoplasmic sperm injection) is required to fertilize frozen eggs because the outer shell hardens during cryopreservation. Embryos develop in the laboratory for 3-5 days. Optional genetic testing (PGT) is available. The embryo is then transferred to your uterus, with pregnancy testing 10-14 days later. The entire process from thaw to transfer takes approximately 2-3 weeks.

OHSS occurs when ovaries overrespond to stimulation medications. Mild symptoms (bloating, discomfort) affect 20-33% of patients and resolve on their own. Moderate OHSS (nausea, vomiting, fluid accumulation) occurs in 3-6% and may require monitoring. Severe OHSS (breathing difficulty, blood clots, kidney issues) is rare at 0.1-2% and requires hospitalization. Risk factors include age under 30, low BMI, high AMH levels, PCOS, and previous OHSS. Modern protocols using GnRH agonist triggers significantly reduce severe OHSS risk.