Every woman is born with a finite number of eggs. However, these eggs lose their ability to function properly over time. The resulting decline in reproductive ability can make it difficult or impossible for a woman to get pregnant at a later point in her life when she is ready to start a family.
Knowing this today, a woman now has the option to freeze her eggs (oocyte cryopreservation) at her current, younger age and store them for as long as she wants (egg banking). This way, she can preserve her fertility until she is ready to start or grow her family.
Why egg freezing?
There are many reasons why a woman would opt to preserve her fertility. They include:
- Medical—some women have disorders or illnesses that may lead to irreversible damage to their ovarian function. For example, chemotherapy and/or radiation used to treat cancer can also destroy a woman’s or girl’s ovaries.
- Personal—some women may wish to delay their pregnancy due to career pursuit or wanting to wait for the right one before starting a family. For some, they may already have children but want to use their younger eggs in the future when they are ready to have a second sibling. Egg freezing is also an option for women and couples going through IVF who prefer to freeze their surplus eggs rather than their embryos.
Who should consider egg freezing?
- Those who want to save their eggs to create their future family. Ovarian function of the woman will deteriorate due to ageing. Eggs are at their most healthy and viable in a woman’s 20s and early 30s. Number of follicles produced will be getting less. Freezing eggs is the good fertility preservation for women who intend to get marry at older age. After years of freezing, oocytes being thawed could undergo ICSI and get fertilised. Embryos will then be transferred in the uterus. Compare to frozen embryo and frozen blastocyst, frozen oocyte has lower survival rate. Therefore, choose the right time to freeze the eggs is critical. Usually, we choose to freeze oocytes which are in MII stage. According to statistics, oocyte has better survival at MII stage.
- Women who have a serious medical condition such as cancer can preserve their future fertility with egg freezing before they undergo procedures such as chemotherapy, radiation or surgery that may damage their ovaries or decrease their fertility.
- Women who are undergoing In Vitro fertilisation (IVF) procedures may choose to freeze their eggs, rather than embryos, to use in the future. Egg freezing is also an option when sperm is not available for fertilisation on the day of egg retrieval.
- Women with severe ovarian cysts or cancer may need to consider ovarian removal. The removal of ovaries means that a woman will no longer be able to produce eggs naturally. If the uterus is left intact, we can use frozen eggs to achieve pregnancy when a woman is ready.
Egg Freeze Procedures
The egg freezing process is very similar to the initial stages of IVF. At the beginning the woman will go through ovulation induction. This is where her ovarian follicles are stimulated to develop a larger quantity of eggs through self-administered medication.
Once the follicles housing the unfertilised eggs reach a certain maturity level, which is determined through careful monitoring, our doctor then extracts, or retrieves, the eggs from each follicle in the ovaries using a transvaginal ultrasound-guided aspiration needle.
Monitored anaesthesia care is administered by our licensed anaesthesiologist in order to eliminate discomfort and increase retrieval effectiveness. This egg retrieval is an outpatient procedure that takes no more than 30 minutes.
Once the procedure is finished, the patient may only need 1 day to fully recover and may experience some cramping during that time.
Once the eggs are retrieved, they are immediately given to our in-house laboratory for assessment. Extracted eggs that meet the right conditions would then be ‘flash frozen’ via vitrification and stored in our egg bank.
The now-standard freezing process called vitrification via grid technology allows us to rapidly cool (“flash freeze”) your retrieved eggs without damaging your eggs—a danger that previously challenged embryologists for decades.
Studies show significantly improved success in fertilisation, implantation and clinical pregnancy rates using vitrified eggs over conventionally frozen eggs for most cases. Data also show no increase in birth defects, developmental disorders or chromosomal abnormalities when IVF cycles were conducted with vitrified eggs.
In the past, conventional freezing technology had been inefficient when it came to egg survival and pregnancy rate, more so than embryos due to the more delicate nature of the egg (ovum/oocyte).
With conventional “slow freezing”, ice crystals often form within the egg—effectively destroying cellular integrity during the thawing process.
Recent breakthroughs in cryogenics have enabled our center to add “antifreeze” to the process. This “antifreeze,” known as cryoprotectants, lowers the temperature at which the cells will freeze. It also increases the viscosity of the cell. When the temperature of that syrup is brought down rapidly, the solution turns to anamorphic ice without ever crystallising (vitrification), thus reducing the likelihood of damage when thawing.
When the woman is ready to start her family, she can have her banked eggs thawed and fertilised with either her partner’s or donor’s sperm. She may select Intracytoplasmic Sperm Injection (ICSI) to help with fertilisation.
Once her egg is fertilised, she can choose other micro-manipulation techniques such as Assisted Hatching (AH) and Pre-Implantation Genetic Screening (PGS) to select the best embryo(s) for implantation. This process is essentially for the latter stages of the IVF cycle. All the same tests and micro-manipulation techniques may be used to increase chances of pregnancy.
Egg freezing is a viable option for women who want to preserve their fertility. Egg freezing and the vitrification process are considered as the “gold” standard in fertility treatment. Vitrification, which is a rapid-freezing process, solved the problems that occurred with previous egg freezing methods, like slow freezing, and has led to higher success rates of both implantation and live births.
Studies show that fertilisation and pregnancy rates for frozen oocytes (or eggs) are similar to results obtained using fresh oocytes during the IVF/ICSI process. Researchers also found that using frozen eggs does not lead to an increase in birth defects, chromosomal abnormalities or developmental deficiencies.