Egg Freezing

Oocyte cryopreservation preserves your eggs at their current genetic quality for future use. Egg quality — particularly chromosomal integrity — declines with age. Freezing is a way to “lock in” your biological age: eggs frozen at 32 will behave like 32-year-old eggs when used, regardless of how old you are at that point.

This matters because chromosomal abnormalities in eggs are the leading cause of failed implantation and early pregnancy loss. Freezing earlier means freezing better eggs.

The optimal window for egg freezing is generally between 25 and 35 years. If you are younger, you may have more flexibility in deciding when to freeze your eggs, but biologically, earlier is better. This does not mean you should wait until 35: ovarian aging varies from person to person, and egg quality gradually declines with age.

Between 35 and 40, egg freezing can still be a valuable option. If you are already in this age range, the sooner the better, as egg quality cannot be recovered over time. Outcomes become more variable with age, and more eggs may need to be frozen to achieve the same probability of a future pregnancy.

After 40, success rates decline significantly and individual evaluation becomes especially important. Age is one of the most important factors, but it is not the only one. Ovarian reserve, assessed through AMH (anti-Müllerian hormone) levels and antral follicle count on ultrasound, helps estimate how many eggs may realistically be retrieved in a stimulation cycle.

• Step 1 — Ovarian stimulation: Injectable medications for 10–12 days with close ultrasound and hormone monitoring to track follicle development
• Step 2 — Egg retrieval: Transvaginal aspiration under light sedation, approximately 20 minutes
• Step 3 — Vitrification: Mature eggs are flash-frozen using the vitrification protocol — ultra-rapid cooling that prevents ice crystal formation
• Step 4 — Storage: Eggs are stored in liquid nitrogen until you’re ready to use them, with no degradation over time
• Step 5 — When ready: Eggs are warmed, fertilized via ICSI, cultured to blastocyst stage, and transferred to the uterus

No. The quality of vitrification depends heavily on the laboratory’s equipment, the embryologist’s experience, and the cryoprotectant materials used. Survival rates after egg warming — and the percentage that fertilize and develop normally — vary significantly between centers.

At CEGYR, egg freezing is performed by specialists with extensive vitrification experience. The laboratory uses premium materials and follows strict quality protocols. These factors translate directly into the number of usable embryos you’ll have available when you decide to use your eggs.