In this article:
Why Would You Freeze An Embryo?
Embryo freezing is common following fertility procedures. Examples include IVF and ICSI.These techniques fertilise eggs with sperm and may produce additional embryos. If you want to freeze excess embryos and use them later, you can:
- Postpone or cancel implantation into your uterus once an egg has been fertilised
- Want to postpone IVF till a later date
- Want an alternative in case early fertility treatments fail
- Instead of destroying useless embryos, consider donating them to other individuals who are trying to conceive or researchers
What Is The Difference Between Egg Freezing And Embryo Freezing?
Embryo cryopreservation freezes a fertilised egg. Fertility programs may also provide egg freezing, which involves freezing unfertilised eggs.Does Freezing Harm Embryos?
Freezing may harm embryos. Freezing them later might also cause harm. If numerous embryos are frozen, one or more may not survive the procedure. Your healthcare professional will discuss with you if your embryos are acceptable for freezing, thawing, and implantation.What Happens Before Embryo Cryopreservation?
You must provide your consent to freeze embryos. Your healthcare professional will offer you consent paperwork to read and sign. The papers should include facts like:- How many embryos will be frozen
- How long they will be kept (usually ten years)
- What happens when the storage time ends
- What happens if you die or become too unwell to make choices before the storage term ends
- What the embryos can be utilised for
- The cleavage stage occurs when a single cell multiplies to four to eight cells after about 72 hours
- Blastocyst stage occurs when a single cell multiplies to 200 to 300 cells after five to seven days
What Happens During Embryo Cryopreservation?
There are two ways to freeze embryos: vitrification and gradual freezing.In vitrification, fertility professionals
- Apply a cryoprotective substance (CPA) to the embryos. CPA is a liquid that, like antifreeze, protects cells against ice crystals
- Place the embryos immediately in liquid nitrogen containers at -321° Fahrenheit (196.1° Celsius)
Although slow freezing is less commonly practised, certain reproductive specialists may continue to rely on it. Fertility doctors use slow freezing to:
- Use less cryoprotective agent (CPA) in the embryos than when they were vitrified
- Place the embryos in a cooling unit that gradually lowers their temperature over a two-hour period
- Remove the embryos from the chiller and store them in liquid nitrogen containers at -321° Fahrenheit (-196.1° Celsius)
For either procedure, the embryos are:
- Stored in canisters that resemble little straws
- Labelled with information that identifies them as yours
What Happens When The Embryo Freezes?
When stored embryos are required later, a fertility expert will:- Withdraw the embryos from liquid nitrogen
- Allow them to gradually recover to normal temperatures
- Soak them to eliminate the CPA
- Use the embryos as directed (for example, implant them in your uterus)
What Are The Benefits Of Embryo Cryopreservation?
Embryo freezing may help individuals become pregnant later in life if they are experiencing present obstacles, such as:- Getting older
- Gender transformation
- Infertility difficulties
- For social/personal reasons, such as seeking further education or having professional obligations, you may choose to postpone childbearing for a few years
- Treatment that may impair fertility (e.g., chemotherapy or pelvic radiation treatment for cancer)
- An upcoming military deployment
- Women without a partner may be worried about their age and want to freeze eggs or embryos created with donor sperm
What Are The Risks And Problems Associated With This Procedure?
Embryo freezing does not offer any risks to subsequent pregnancies, such as congenital defects or health issues. In reality, outcomes research on frozen-thawed embryos reveals decreased incidence of preterm delivery, low birth weight, growth limitation, and perinatal death.The primary risks linked with embryo cryopreservation are:
- Damage to embryos occurs during the freezing procedure
- Embryos that are not suitable for freezing
- Failure to get pregnant after embryos have been thawed and implanted
- Increased incidence of pregnancy-related medical complications such as preeclampsia and placental accrete spectrum
- Multiple births occur when more than one embryo is implanted (twins or triplets)
Is Frozen Embryo Transfer Successful?
Frozen embryo transfer is the process of thawing an embryo and implanting it into a woman's uterus. The process is usually successful. However, rates vary depending on several circumstances, including:- Both parents' general health
- Mother's age at the time of egg retrieval
- Endometriosis, fibroids, and uterine polyps are all examples of fertility difficulties
- Previous success or failure with reproductive treatments and pregnancies
You or your partner can change your mind at any point during the process. If one of the two parents decides not to go ahead with the procedure, the fertility doctor cannot legally continue.
If one parent decides not to proceed after the embryos have been frozen, the specialist may recommend a waiting period to be sure. The embryos will then be taken out of storage and allowed to expire.
Success Rate of Embryo Freezing Based on Age
Success rates of embryo freezing are largely dependent on age. This is both determined by the age at which the eggs are retrieved and fertilised. Due to egg quality declining with age, younger women have a higher success rate with embryo freezing. As the age increases, more eggs may be needed to achieve success rates.
Alternatives to Embryo Freezing
There are a few alternatives to embryo freezing that you can consider
- Egg freezing: Egg freezing or freezing unfertilised eggs is a brilliant option for single women or women who have not decided on a sperm donor. It allows the eggs to be stored for future use without needing sperm at the time of freezing.
- Ovarian tissue cryopreservation: This involves preserving ovarian tissue for transplantation in the future. This is a good option for those undergoing cancer treatment, as it is often not possible to wait for egg retrieval in such cases. It may also be used for prepubertal girls. However, this method is still considered experimental.
Criteria For Candidate Suitability
Ideal candidates for embryo freezing include the following- Women who are 35 or under the age of 35, as a younger age is associated with higher rates of success
- Couples or individuals who are undergoing medical treatments, for example, chemotherapy can affect fertility
- Couples who are opting for IVF and have surplus embryos
Counselling Before Embryo Freezing
Embryo freezing can be challenging in a lot of ways, which is why it is important to undergo thorough counselling before proceeding with it. Counselling is very important to understand
- Potential risks and side effects of embryo freezing
- Medical procedures involved in embryo freezing including ovarian stimulation and egg retrieval
- Factors influencing outcomes such as the candidate's age and egg quality, along with success rates
- Legal and ethical considerations including the disposal of unused embryos
- Psychological and emotional impact of embryo freezing
Thorough counselling is extremely important when you are investing your time and energy into a procedure like embryo freezing. It will prepare you for all the outcomes and help you make informed decisions that align with your values and ethics.
Impact of Storage Duration on Success
Studies suggest that the duration of storage does not have a significant impact on success rates or pregnancy outcomes. Embryos that have been stored for a longer period of time, even over a decade, have led to successful outcomes with healthy pregnancies and births.
Follow-up Care After Embryo Transfer
Any medical procedure requires follow-up and care. Follow-up and care after embryo transfer generally include the following
- Monitoring and rest: Patients are advised to rest for some time after the procedure and monitor themselves for any unusual symptoms.
- Medications: Patients may be prescribed hormonal support medications like progesterone to support the uterine lining and implantation.
- Pregnancy test: About two weeks after the embryo transfer procedure, a blood test is scheduled to check whether pregnancy has occurred.
- Further care: In case of a positive result on the pregnancy test, regular prenatal care will begin. If there is no pregnancy, there will be a consultation to discuss further options.
Embryo freezing is the technique of freezing and storing fertilised eggs for later use. It may help individuals maintain their fertility and have alternatives for conception later in life. If you're thinking about embryo cryopreservation, see your primary care physician, gynaecologist, or fertility specialist.
It is very important to maintain open communication with your doctor throughout the process to get personalised guidance and address any concerns. Embryo freezing is a good option for fertility preservation, however, it is important to keep all factors in mind, such as age and personal circumstances.
FAQs on What is Embryo Freezing (Cryopreservation)?
- Is it worthwhile to freeze embryos?
Choosing to freeze embryos is a personal choice. The costs of reproductive treatments vary greatly, and medical insurance may not cover them. You must examine your aims, the expenses, ethical difficulties, your partner's preferences, and other factors. - What happens if I don't use frozen embryos?
If you do not use frozen embryos, you may: Discard them: The reproductive clinic will take them out of the freezer and let them freeze, rendering them no longer viable, donate them to someone else who is trying to have a child, donate them for study, donate them for educational reasons (such as training future fertility doctors)
