The egg freezing procedure, also known as oocyte cryopreservation, may extend the fertility period and may make it possible for older women to conceive. Egg freezing is also an alternative for women that need to undergo chemotherapy or radiation therapy and would like to start a family after the treatment. Pregnancy after egg freezing is possible and has high chances of success, provided the egg freezing procedure is performed without hurting the egg and the woman's reproductive system is healthy.
The Egg Freezing Procedure
The egg freezing procedure is a revolutionary technique that involves several steps. First, the eggs are stimulated to mature and are extracted. Then the eggs are frozen using either the slow cooling method or the vitrification method. When the woman is ready to start a family, the eggs are thawed and fertilized. Each step will be performed carefully, so that the quality of the eggs is not compromised. The eggs will be stored in liquid nitrogen storage containers that have constant temperatures, so that the eggs won't accidentally defrost.
Theoretically, the eggs can be kept for an infinite number of years before being thawed. However, it is not possible to determine if the quality of the eggs will be preserved after several years of storage.
Due to the fact that the protective layer of the egg will be harder after the freezing procedure, the fertilization should be performed in vitro. The egg will be injected with sperm through a procedure known as intracytoplasmic sperm injection or ICSI, which is also used in the in vitro fertilization process. The embryo will then be transferred to the mother's uterus.
Pregnancy after Egg Freezing
The chances of pregnancy after egg freezing are high and comparable to the chances of getting pregnant before the egg freezing procedure. Studies show that the success rates of eggs that are fertilized after freezing is between 80 and 90%.
If the eggs are damaged during the freezing process, the fertilization is less likely to be successful. However, the egg freezing technology has been perfected so as to preserve the eggs without compromising them.
The pregnancy may also be affected if any of the elements of the woman's reproductive system are damaged. If this is the case, a surrogate mother may be a viable solution.
The number of children born with birth defects or chromosomal defects resulting from egg freezing is similar to the number of cases resulting from natural conception. Children conceived from frozen eggs are not more at risk of developmental defects than the children resulting from natural conception.
Successful Cases Reported
The number of successful cases of pregnancy after egg freezing reported is around 50,000 per year, and this is a total number reported for 25 countries. Starting from the 1970s when egg freezing was pioneered, the estimated number of worldwide human births obtained through fertilization of frozen eggs is between 300,000 and 500,000. Even though egg freezing is still considered an experimental method, more and more women are considering this procedure.