Yes, you can still get pregnant after freezing your eggs, though the outcome is never guaranteed and requires medical procedures. This fertility preservation method, scientifically known as oocyte cryopreservation, secures the quality of your eggs at a specific point in time. The process involves retrieving the eggs, preserving them at very low temperatures, and storing them until needed for assisted reproductive technologies.
Preserving Fertility: How Egg Freezing Works
Preserving the unfertilized egg (oocyte) relies on vitrification, a sophisticated form of ultra-rapid freezing. Eggs are large cells with high water content, making them susceptible to damage from ice crystal formation during cryopreservation. Vitrification bypasses this issue by plunging the eggs directly into liquid nitrogen at -196°C.
Before freezing, eggs are treated with high concentrations of cryoprotectant solutions. These solutions act as biological antifreeze, removing water from the cell to minimize crystal formation. Rapid cooling causes the cell to solidify into a glass-like state, or “vitrify,” rather than crystallize. This modern method significantly improved egg survival rates upon thawing, which typically exceed 85% to 90%.
The Journey to Conception: Steps After Thawing
When using stored eggs, the process begins with warming, where the eggs are rapidly brought out of their vitrified state. Once thawed, the eggs are ready for fertilization through an in vitro fertilization (IVF) process. A specialized technique is almost always used for fertilization because freezing can affect the egg’s outer layer.
This technique is Intracytoplasmic Sperm Injection (ICSI), where a single, healthy sperm is injected directly into the center of each mature egg. Fertilization is monitored, and if successful, the fertilized egg becomes an embryo. The embryo is cultured in the laboratory for five to seven days to develop to the blastocyst stage.
The final step for achieving pregnancy is the embryo transfer, which requires preparing the uterus to be receptive. Hormonal medication may be administered to thicken the uterine lining (endometrium). The selected embryo is then placed into the uterus using a thin, flexible catheter.
Understanding the Odds: Realistic Success Rates
Success with frozen eggs depends highly on two main variables: the woman’s age when the eggs were frozen and the total number of eggs stored. Egg quality declines as a woman ages, so eggs frozen earlier have a greater chance of resulting in a live birth. The woman’s age when using the eggs does not affect egg quality, only the uterine environment.
For women under 35 who freeze eggs, the probability of achieving one live birth is estimated to be 70% to 90% if they have stored 10 to 20 mature eggs. For instance, a woman aged 30 to 34 who stores 18 or more eggs has an approximate 80% chance of a live birth. The success rate drops significantly for women who freeze fewer eggs or who are older at the time of the procedure.
For women over 35, the number of eggs needed to achieve a similar outcome increases significantly. Women who stored ten eggs after age 35 had a success rate around 30%. The overall chance of a single frozen egg leading to a live birth is generally estimated to be between 4% and 12%, emphasizing the need to freeze a sufficient quantity. Individual outcomes are unique, depending on factors like sperm quality, overall health, and clinic expertise.