The following article by Anne-Gerard Flynn is courtesy masslive.com/The Republican
Preserving fertility is an issue for some women. This can be the result of facing cancer treatments that leave a woman infertile, or other medical reason, or lifestyle reasons that delay child bearing.
An option becoming more available, at Baystate Health and other facilities in the country, to women is oocyte cryopreservation, or the freezing of unfertilized eggs.
This procedure enables a woman to preserve her eggs for future fertilization. Mature eggs are harvested after a woman undergoes the hormone-injection process that is used with in-vitro fertilization. The eggs are then frozen until the woman wishes to become pregnant. They are then thawed, fertilized by injection with a single sperm and transferred as embryos to the uterus. While a woman's ability to produce eggs and become pregnant lessens with age, the ability of the uterus to carry a pregnancy does not.
The procedure is generally done on women up to 38 years of age. Statistics show that if, 10 eggs are frozen, seven generally survive the thaw with five to six projected to fertilize and become embryos. Some 5,000 children have been born from frozen eggs.
Prior to freezing, the egg cell's water content is replaced with another fluid to avoid the formation of ice crystals. It is preserved using either a slow-freeze method or a flash-freezing process known as vitrification.
Costs are around $10,000 for egg freezing, around $500 annually for storage and about $5,000 for egg thaw, fertilization and thaw. It is generally not covered as an elective procedure by insurers.
Sperm cells have been frozen, thawed and successfully used in treatment for more than 40 years. Five million children have been born worldwide since in-vitro fertilization began in 1978.
The following is an interview with Dr. Cynthia K. Sites, Baystate Health's chief of the division of endocrinology and fertility.
How long has the option of women freezing their eggs been available, and when and why did Baystate start to offer this service? When did it start freezing embryos and sperm?
Egg freezing by the process of vitrification became common in the early 2000's. The American Society for Reproductive Medicine declared in 2012 that egg freezing was no longer considered experimental. Baystate began egg freezing about 1 1/2 years ago. Embryo freezing and sperm freezing have a longer track record, both at Baystate and nationwide. We have done both at Baystate for at least 25 years.
What would make a woman consider this particular option over say, freezing an embryo, and are there any age or other restrictions?
Women might consider this if they would like to or need to freeze eggs for fertility preservation with a cancer diagnosis, in particular if they do not have a partner. Embryo freezing has a longer track record and should be chosen preferentially for women with a male partner. There are no age restrictions, but procedures are more likely to be successful for women 38 years old and younger.
As far as the science, what is involved in freezing what has been called the largest human cell? How many are harvested for freezing, how are they prepared, how long can eggs be frozen? Are they fertilized any differently?
As many eggs as possible are retrieved with IVF. They are frozen in straws by a process called vitrification and maintained in liquid nitrogen. They are allowed to recover for two hours after thawing before being fertilized using a process called ICSI (intracytoplasmic sperm injection). This is very similar to fertilization with fresh eggs.
Where are the frozen eggs stored, how are they labeled and what is involved in the thawing process?
Frozen eggs are stored in our IVF lab in liquid nitrogen. They are labelled with the patient's name and medical record number.
How similar is the process to IVF for what a woman must do?
It is very similar. The big difference is that eggs are frozen after retrieval and not fertilized or transferred until a later cycle.
What have studies thus far revealed? What are the success rates in terms of births from eggs that were initially frozen, and what has been learned in terms of birth defects versus traditional conception and IVF.
There are few studies looking at long term outcomes of egg freezing, but so far, babies born following this technology have not been found to be different than those born after traditional IVF using fresh eggs, frozen sperm, or frozen embryos. I expect that we will see more data on this in the future as more procedures are performed.
Is Baystate the first in Western Massachusetts to freeze eggs? How many women have elected to do this? What are the variety of reasons?
Yes, we are the first in Western Mass to freeze eggs successfully (and the only program in Western Massachusetts). The only other programs in Massachusetts to do this are in Boston. We have had about eight women do this, most of which have been diagnosed with cancers who desire fertility preservation. Two women recently delivered babies following these procedures at Baystate.
How do cancer treatments interfere with a woman's fertility? Is fertility preservation a topic more incorporated in options discussed for women undergoing such treatment? Would some of the steps needed to produce eggs further put a woman at increased risk for breast cancer?
Cancer treatment, especially chemotherapy, reduces or eliminates the egg numbers in women and the sperm numbers in men. The removal of ovaries has a similar and expected outcome. Many but not all oncologists in the region are aware that we successfully freeze sperm, eggs, and embryos.
With regard to breast cancer, many of our patients who freeze eggs or embryos have breast cancer. We use a medicine called Letrozole with the ovarian stimulation drugs to keep the estradiol low and reduce risk for breast cancer growth.
What is the cost of harvesting the eggs, storing them, thawing them and then the IVF? Is there financial assistance available? Do some insurers cover this?
Major insurers in our region such as Health New England and Blue Cross/Blue Shield cover egg freezing or embryo freezing for women with cancer who desire fertility preservation. They do not cover elective egg or embryo freezing. The total cost is similar to an IVF cycle with ICSI, but divided in two time points since the eggs are retrieved and frozen, then later thawed, fertilized, and transferred into the uterus. One pharmaceutical company provides medication for the cycle free of charge for cancer patients who do not have coverage.
What happens if someone does not want to use her eggs, or does not use all of them? Also, is this option more appealing to women with religious objections to freezing embryos?
If someone does not want her eggs or embryos, she can contact the lab and request that they be discarded. Some women with religious objections to creating many embryos may request that some eggs as well as embryos be frozen.