What Is
Egg Freezing?

Who Is A Good Candidate
For Egg Freezing?

A good candidate for egg freezing is:.

• A woman who wishes to preserve younger eggs for future use. The number and quality of eggs deteriorates significantly with age, resulting in infertility. Hence, egg freezing helps preserve the fertility when done at a younger age.
• A woman who is to undergo treatment for cancer or another illness that may affect future fertility. Treatments like chemotherapy tend to have harmful effects on fertility, hence egg freezing prior to it may allow the woman to have children at a later date.
• A woman undertaking IVF (in vitro fertilization). If the male partner is unable to produce sufficient sperm on the day of egg retrieval, egg freezing is required.
• A woman who isn’t ready to have children and wishes to conceive in the future.

Egg Freezing
Success Rates

Generally, egg thaw and fertilization rates of 75% are estimated in women up to the age of 38 years. So, if 10 eggs are frozen, 7 are estimated to survive the thaw, out of which 5-6 are fertilized to become embryos. About 3-4 embryos are then transferred into the woman’s uterus. It is thereby recommend that, for each pregnancy attempt, at least 10 eggs are stored.

Egg Freezing
Procedure

STEP 1: Screening Tests

Prior to undertaking the egg-freezing process, a woman may have to undertake screening tests as follows:

Infectious Disease Testing: For detecting certain infectious diseases like HIV. This is so, because infectious eggs are generally stored differently as compared to other eggs.

Ovarian Reserve Screening: To determine the ovaries response to fertility medication. Here, on the third day of the woman’s menstrual cycle, the doctor tests the concentration of estradiol and follicle-stimulating hormone in the blood. Ovarian ultrasound may also be done to better understand the function of ovaries.

STEP 2: Ovarian Stimulation

This stage uses medication to stimulate the ovaries to produce more eggs, or ova. Normally, a woman produces one egg per month. Synthetic hormones induce the ovaries to produce several eggs. After about 1-2 weeks, when the follicles are prepped for egg retrieval, injections of human chorionic gonadotropin or other medications help the eggs mature. Medication may also be administered to prevent premature ovulation.

STEP 3: Egg retrieval

Through a transvaginal ultrasound, the mature egg is retrieved after sedating the patient. The ultrasound images work as a guide, through which, the health care provider inserts a thin needle through the vagina and into the ovary and sacs (follicles) containing the eggs. The needle is connected to a suction device, which pulls the eggs and fluid out of each follicle, one at a time. The procedure is repeated for the other ovary. There may be some cramping after the procedure, but it generally goes away within a day.

STEP 4: Freezing

When the unfertilized eggs are harvested, they are cooled to subzero temperatures to restrict all biological activity and preserve them. Since it is difficult to freeze an unfertilized egg, the health care provider may use substances called cryoprotectants to prevent ice crystals formation during the freezing process.

Cryoprotectants may be used in any one of the following methods:

Vitrification: Here, at first, high concentrations of cryoprotectants are used along with rapid cooling, so that intracellular ice crystals don’t get time to develop.

Slow-freeze method: Here, at first, low concentrations of cryoprotectants are used; and as the temperature gradually reduces and the eggs’ metabolic rate declines, higher concentrations of cryoprotectants are utilized. This method can also be used to guard the eggs from exposure to toxins present in the cryoprotectants.