The Process of Oocyte Cryopreservation
In order to freeze eggs, we first need to get access to them. The procedure for doing this is called egg retrieval; it’s exactly the same as the first stage of IVF, with the only difference being that the eggs aren’t fertilized right after being retrieved.
Ovulation Induction
The first step is to encourage the woman’s body to produce eggs. During most normal menstrual cycles, a woman produces only one ripe egg (occasionally two). For the purposes of egg retrieval, it’s desirable for her to produce more eggs. Ovulation induction medications are given to cause the body to do this; these are given daily by injection, for 7-10 days per cycle. When the eggs are ripe, a final injection of another medication is given, and the eggs are retrieved the next day.
Egg Retrieval
The egg retrieval procedure usually takes place right in our office, with the providers you’re already comfortable with. The patient may receive sedation to help her stay calm, but it’s not necessary for her to be under anesthesia. Using ultrasound guidance, the doctor passes a needle through the woman’s vagina toward each ovary, and the eggs are removed through gentle suction.
These first two steps may need to be repeated in order to retrieve as many eggs as desired. In general, it’s recommended that a woman store 10 eggs per pregnancy attempt she’d like to make later, because not all eggs will survive the thawing process and not all of those will successfully be fertilized. For a woman in her 20s, 10 to 20 eggs are typically retrieved per cycle
Egg Freezing
The process of cryopreservation is the last step. If eggs are frozen too quickly, ice crystals form within them, destroying the cell. In order to keep the eggs viable, much of the water must be removed from the cell. Chemicals called cryoprotectants are used to accomplish this. The eggs are then frozen through a very slow cooling, or through a flash-freezing process called vitrification. Vitrification requires higher levels of cryoprotectants, but scientific evidence indicates that it results in higher pregnancy rates when the eggs are later used.
How Are the Eggs Used?
The frozen eggs will later be used for IVF (in vitro fertilization). A few eggs will be thawed. Then they’ll be combined in the laboratory with sperm (either sperm collected from the woman’s partner, or donor sperm). Because the shell of the egg hardens with the freezing process, fertilization is more difficult for these eggs than for fresh eggs, so ICSI (intracytoplasmic sperm injection, or assisted fertilization in which the sperm is injected directly into the egg cell) is generally used. Once the embryos are formed, they’re incubated for a few days, and then up to four embryos are selected. The process by which they’re placed into the woman’s uterus is called embryo transfer, and takes place in the doctor’s office. A thin flexible tube is used to pass the embryos through the cervix and into the uterus; this is not usually painful, though mild cramping may occur. A pregnancy test will be done 12-14 days after the embryo transfer, to see whether the embryos have successfully implanted. When you choose to freeze your eggs with our fertility clinic near Scottsdale, you’re choosing a relationship with us that will serve you well. Even at this stage of your fertility treatment, we’re already focused on your holistic health, giving you the tools you need to align your lifestyle with your health goals. When you come back later to use those frozen eggs to start your family, we’ll continue to help you build on that foundation. Your future family will have the healthiest possible start.
