Freezing Eggs to Preserve Fertility
Women at risk of losing their fertility due to cancer, premature ovarian insufficiency (POI), or other causes may want to consider the option of freezing their own eggs for future use to achieve pregnancy.
POF usually occurs in women under the age of 40 and can happen as early as the teen years. It is most often associated with cancer treatments, such as radiation, chemotherapy or surgery that can limit future reproductive potential. Genetic disorders, such as Turner syndrome, and autoimmune diseases, such as lupus, can also cause POF. In some cases, the cause of POF is unknown.
Women at risk for POF have a variety of fertility preservation options for achieving future pregnancy. These options include in vitro fertilization (IVF) to create frozen embryos for future implantation, or the use of donor eggs. However, egg freezing may be the method of choice for very young women or for women who desire a biological connection to future pregnancies.
Additionally, some couples undergoing IVF do not want to create human embryos that will not be immediately implanted. Instead, these couples may opt to save extra eggs that were retrieved through the IVF process and freeze them for later potential use.
Egg Freezing Process
Unlike sperm and embryos, which have been successfully frozen for years, eggs contain a great deal of water making them more difficult to freeze and thaw. When eggs are frozen, ice crystals can form within the egg and destroy the cell’s structure.
At the Reproductive Medicine Center, a highly specialized technique called vitrification is used to freeze eggs. Vitrification, which means “turning to glass,” freezes eggs very quickly, which prevents the formation of ice crystals.
The procedure for retrieving eggs for freezing is similar to the process used to retrieve eggs for IVF. Medications are used to stimulate the ovaries to produce multiple eggs. When the eggs are judged to be mature, they are retrieved by needle aspiration. In this in-office procedure, the physician uses ultrasound to guide a needle through the vagina and into the ovaries. An anesthesiologist is present to provide pain medication and sedation so the woman does not feel pain.
Once the eggs are collected, water is removed from the egg cells and the eggs are quickly frozen using the vitrification process and stored for later use. When the eggs are to be used, they are quickly thawed in a reverse process. Since freezing may compromise the egg membrane and make it more difficult for sperm to penetrate the egg, eggs are fertilized using intracytoplasmic sperm injection (ICSI), an assisted reproductive technology that injects one sperm directly into an egg. Resulting embryos are then implanted into the woman’s uterus with the hope that pregnancy will occur. To sustain the pregnancy, a woman would need to take additional medications and hormones to replace those naturally produced by her ovaries.
At the Reproductive Medicine Center, the procedure has produced fertilized embryos and has also resulted in successful pregnancies.
Women at risk of losing their fertility due to medical circumstances should discuss their treatment options with their physicians. We will be happy to answer your questions related to preserving fertility for women with cancer and other fertility concerns.
Learn more about the Fertility and Reproductive Medicine on the Froedtert & the Medical College of Wisconsin website.