Data on pregnancies resulting from frozen eggs is mixed. A small review of egg-thawing data found that 414 eggs thawed in 2013 resulted in 99 live births, meaning that slightly fewer than one in four cases were successful.
This suggests that women may need to undergo multiple IVF cycles to become pregnant.
Factors that affect the success of egg freezing and thawing procedures include:
• The age of the woman when her eggs are frozen: Younger women tend to produce more eggs, which are less likely to have defects
• The age of the woman at the time of egg thawing and IVF: Younger women are more likely to have successful pregnancies
• Sperm quality: Healthy sperm is more likely to produce a healthy embryo and a successful pregnancy
• The clinic: The success rates of freezing and thawing eggs vary between clinics
• The number of eggs frozen: A larger number of eggs offers more opportunities for IVF cycles
How Long Will Frozen Eggs Last?
Freezing an egg stops it from aging. A frozen egg that is a few years old will typically be healthier than a fresh egg from an older woman.
Most studies on frozen eggs looked at eggs that were just a few months old. It remains unclear how long eggs can safely be frozen.
Most researchers suggest that a woman should freeze her eggs when she is in her mid-to-late 20s, for use in her 30s. Women who are considering IVF in the future should not delay any longer than necessary.
According to the University of Southern California’s fertility clinic, about 75 per cent of eggs survive the thawing process.
Embryos are more likely to survive both freezing and thawing than eggs, and they are more likely to result in a successful pregnancy. If a woman has a partner, or if she intends to use donor sperm, she should consider freezing embryos rather than just eggs.
Who Should Consider Freezing Their Eggs?
Younger women have significantly higher egg-freezing success rates than older women do. Women who wish to have their eggs frozen should do so as early as possible. Most clinics work with women under 40 years old. Some clinics place restrictions on women in their 40s, and few will allow women over the age of 45 to freeze their eggs.
There are no guarantees that frozen eggs will lead to a live birth. The chance of each frozen egg leading to a live birth is between 2 and 12 percent. Factors such as uterine health, age, and overall health affect a woman’s chance of becoming pregnant.
Some reasons women freeze their eggs include:
• Career and educational plans: Women who wish to pursue advanced degrees or demanding careers may freeze their eggs when they are young to ensure access to healthy eggs when they are older.
• Romantic delays: Women who want to have a child with a partner, but who have not yet found one, may freeze their eggs for future use.
• Cancer: Chemotherapy and other cancer treatments typically destroy fertility. Reproductive cancers might mean a woman’s ovaries are removed.
• Infections, organ failure, and other health concerns: A wide range of health problems can harm egg quality.
Freezing eggs offers future hope to a woman who is receiving treatment for a serious illness that may reduce fertility.