Oocyte (egg) freezing or mature oocyte cryopreservation is a contemporary method of preserving a woman's future fertility. In this procedure, unfertilized eggs are removed from a woman's ovaries, frozen, and stored for future fertilization use. That involves thawing those stored eggs to be fertilized with sperm and implanted in the woman's uterus through in vitro fertilization.
Why is the oocyte freezing procedure done?
If a woman wants to ensure that she can get pregnant later but is not now ready to do so, oocyte freezing is a fantastic option. Oocyte freezing does not require sperm since the eggs are not fertilized before they are frozen. Women who opt for oocyte freezing must take fertility drugs for inducing ovulation, producing multiple eggs or oocytes that can be extracted and stored for future use. A woman might consider oocyte freezing if:
- They have one or more medical disorders or situations that may affect their fertility condition. These may include gender diversity, like being transgender or having sickle cell anaemia, etc.
- They need medical care for cancer or other serious illnesses that could prevent them from getting pregnant in the future. For instance, a few medical procedures, such as chemotherapy and radiation, can impact a woman's fertility.
- A woman is going through in vitro fertilization. For ethical or religious reasons, some people prefer egg freezing over embryo freezing when they undergo in vitro fertilization.
- A woman's desire to hold onto their younger eggs for use in the future. A woman may benefit from freezing her eggs earlier if she is ready to get pregnant at a later stage.
What is the procedure for oocyte freezing?
- Ovarian stimulation:
When a woman wants her oocytes frozen, doctors will administer fertility hormones to encourage her ovaries to produce several eggs at a time rather than one egg, which is usually developed in the monthly cycle. Several of these medicines may include hormones to stimulate ovarian function and drugs for preventing the chance of premature ovulation.
Doctors recommend routine blood tests to monitor patients' responses to ovarian-stimulating medications. Vaginal ultrasonography is another procedure doctors use to track the growth of the follicles where the eggs develop. The follicles are then prepared for egg retrieval after 10–14 days.
- Retrieval of Egg
During an egg retrieval operation, sedation is given to a woman. In a procedure known as transvaginal ultrasound aspiration, an ultrasound probe is inserted into the vagina to find the follicles. The eggs are then removed from the follicle using a piece of suction equipment attached to a needle after it has been put into the vagina.
The collected unfertilized eggs are then quickly frozen to a sub-zero temperature to preserve them for future use. The most popular method for freezing eggs is called vitrification.
How to prepare for the oocyte freezing procedure?
When considering oocyte freezing, a woman should opt for a reputable fertility clinic where reproductive endocrinologists and specialists in the field will assist her during the entire process. To better understand their health circumstances, women are given several blood tests before their oocyte freezing procedure, such as ovarian reserve testing and infectious disease testing (HIV, hepatitis B, C).
Is there any risk associated with the Oocyte freezing procedure?
Similar to the complications of ovarian stimulation for IVF, a few mild complications of the oocyte freezing procedure may include ovarian hyperstimulation syndrome, where the ovaries expand, and occasionally fluid builds up in the abdomen and pelvis, a few infections, and chance of bleeding during the egg retrieval procedure, etc.
Oocyte freezing helps prevent the ageing of a woman's egg. Generally, an older egg that has been frozen for a few years has a higher likelihood of fertilization than one that is fresh from an older woman. Doctors advise women to freeze their eggs in their mid to late 20s for use after the age of 30. When a woman chooses to use her frozen eggs, they will be thawed, fertilized with sperm, and then implanted in her womb or the uterus of a gestational carrier.
The general success rate of oocyte freezing depends on several variables, including the woman's age undergoing the process.
Oocyte freezing is an excellent option for any healthy woman who does not yet want to be a mother but still has a few healthy eggs and wants to preserve them.
In general, there is as such no time limit. Experts in IVF have fertilized eggs that have been frozen for 14 years.
The maximum number of eggs that can be preserved varies depending on the woman's age. Eggs will typically survive the freezing and thawing process 6 out of 8 times.
Unfortunately, no. There are other aspects to take into account when attempting to conceive, like a woman's age, health, and how many eggs are stored, etc.