What is this?
The process of freezing unfertilized eggs (eggs that have not been combined with sperm) for future use. These eggs are later thawed and fertilized in the laboratory to create embryos that can be transferred to a woman's uterus. Oocyte cryopreservation is currently being studied as a method of fertility preservation.
Why is it done?
Oocyte (egg) cryopreservation is done for several reasons:
Fertility Preservation: For women who want to delay childbearing due to personal, educational, or career reasons, egg freezing allows them to preserve their fertility at a younger age when egg quality is higher.
Medical Reasons: Women undergoing medical treatments such as chemotherapy or radiation, which can harm fertility, may choose to freeze their eggs before starting treatment.
Pre-Surgery: Women who require surgeries that may affect their ovaries or overall reproductive health might opt for egg freezing as a precautionary measure.
Genetic Conditions: Women with genetic conditions that could impair their fertility in the future may choose to freeze their eggs.
In Vitro Fertilization (IVF): During IVF treatments, excess eggs may be frozen for future use, providing additional opportunities for pregnancy without undergoing another egg retrieval cycle.
Single Women: Single women who wish to have biological children in the future may freeze their eggs until they find a suitable partner or decide to proceed with donor sperm.
Family Planning: Couples who want to space out their children or who face uncertain fertility timelines may use egg freezing as part of their family planning strategy.
Other procedures and interventions needed:
Oocyte (egg) cryopreservation involves several procedures and interventions to ensure the process is effective and the eggs remain viable for future use. These steps include:
Initial Consultation: A thorough consultation with a fertility specialist to discuss medical history, fertility goals, and the process involved in egg freezing.
Ovarian Reserve Testing: Blood tests (like AMH levels) and ultrasound scans to assess the ovarian reserve and determine the appropriate medication dosage.
Ovarian Stimulation: Administration of hormone injections to stimulate the ovaries to produce multiple eggs. This typically lasts 10-14 days and requires regular monitoring through blood tests and ultrasounds.
Monitoring: Frequent visits to the fertility clinic to monitor the response to the hormones, adjusting medication doses as necessary, and tracking the growth and development of ovarian follicles.
Trigger Shot: Once the follicles reach the appropriate size, a trigger shot of human chorionic gonadotropin (hCG) or another hormone is given to induce final maturation of the eggs.
Egg Retrieval: Performed 36 hours after the trigger shot, this minor surgical procedure involves using a thin needle to retrieve the eggs from the ovaries, done under mild sedation or anesthesia.
Egg Evaluation: Retrieved eggs are evaluated in the laboratory to determine their maturity and quality. Only mature eggs are suitable for freezing.
Cryopreservation: Mature eggs are frozen using a process called vitrification, which rapidly cools the eggs to prevent ice crystal formation, thereby preserving their integrity.
Storage: Frozen eggs are stored in liquid nitrogen tanks, where they remain viable indefinitely until needed for future use.
Thawing and Fertilization (for future use): When the woman is ready to use her eggs, they are thawed and fertilized with sperm in the laboratory to create embryos, which are then transferred to the uterus.
Follow-Up: Regular follow-up appointments to monitor the patient’s health and address any questions or concerns related to the process.
These procedures and interventions are critical to maximizing the success of oocyte cryopreservation, ensuring that the eggs remain healthy and viable for future fertility treatments.
Efficacy:
Modern vitrification techniques have significantly improved the survival rates of frozen eggs, with up to 90-95% of eggs surviving the thawing process.
Modern vitrification techniques have significantly improved the survival rates of frozen eggs, with up to 90-95% of eggs surviving the thawing process.