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Freezing Eggs: Advances in Fertility Treatment

Contributor Irene Dimitriadis, MD
5 minute read
A smiling couple sits on their couch, cradling the woman's pregnant stomach.

Family planning and fertility challenges can be complex, especially at certain stages of life. Female fertility declines rapidly in women over the age of 35, and male fertility is not far behind for men over 40. Some people face fertility challenges even at younger ages.

Irene Dimitriadis, MD, a Mass General Brigham reproductive endocrinology and infertility specialist and reproductive surgeon, helps patients and couples who have infertility, or who are planning ahead because of concerns about future fertility. Dr. Dimitriadis is also director of third-party reproduction at Massachusetts General Hospital.

What causes infertility?

Infertility, or the inability to create a viable fertilized egg, can be a challenge for many people who try to have children. Treatment can require different approaches depending on the cause. Infertility causes can be male or female, and can arise from health conditions, genetic factors, medical treatments, or natural aging. Behavioral factors such as smoking and alcohol use also increase the risk of infertility.



One method of fertility treatment is known as cryopreservation, or the process of freezing eggs or embryos. Doctors have been using egg and embryo freezing successfully for decades. In 1984, the first baby was born from a frozen embryo. An embryo develops when sperm fertilizes an egg. In 1986 an Australian woman was the first to give birth using frozen eggs. Today, freezing eggs and embryos is routine and no longer considered an experimental procedure.

Egg freezing may benefit anyone affected by the health conditions, treatment needs, or fertility issues listed below:

  • family history of early menopause (usually defined as between the ages of 40 and 45), which limits the available supply of eggs

  • Known genetic reasons which may limit available supply of eggs at a younger age (such as Fragile X premutation carriers, mosaic Turner’s, etc.)

  • Health conditions like autoimmune disorders, obesity, or eating disorders such as anorexia nervosa

  • Upcoming treatments like chemotherapy or surgical procedures to the reproductive tract, which may impact fertility

  • Planning for future pregnancy and mindful of natural fertility loss due to age

Cryopreservation can help some patients preserve or extend their fertility windows.

I like to think of it as the ability to freeze time for fertility.

Irene Dimitriadis, MD
Infertility Specialist
Mass General Brigham

Egg cryopreservation process

When you begin the process of freezing eggs, whether for immediate or later fertilization, you follow steps designed to ensure your best chances of success. To do this, doctors work to boost egg recruitment levels to their highest before they harvest, or remove, the eggs. The process also includes planning for egg storage with the best possible conditions for freezing and future use.

Ovary stimulation

Before a fertility specialist removes eggs from a patient, the patient takes fertility medications to help them produce the largest possible number of eggs. This increases the overall chance of success, whether the eggs will be frozen and stored on their own or fertilized with sperm and frozen afterward as an embryo.

Egg retrieval: In-vitro fertilization (IVF)

During a procedure called in-vitro fertilization (IVF), a doctor removes eggs from a person’s ovaries. Patients may choose:

  • To combine their eggs with sperm to create an embryo. This is a good option for couples who are having difficulty getting pregnant or want to wait until later to have children.

  • To freeze their eggs by themselves for a future pregnancy. This is a good option for those who don’t have a current male partner or don’t want to use a sperm donor.

An embryologist freezing eggs using the vitrification technique.

The process of freezing eggs

The actual process of freezing eggs has become quite advanced. Embryologists use a technique called vitrification, where they flash-freeze eggs to subzero temperatures in under a minute. They then store the frozen eggs in liquid nitrogen at approximately -196 degrees Celsius.

Doctors have reduced the risk of damaging eggs by using this modern process. Earlier versions of the procedure involved slowly lowering the temperature of the eggs rather than flash-freezing. This risked damage from ice crystals that could form in the eggs, which are composed of mostly water.

Optimal age for egg freezing

Most specialists recommend that eggs be frozen before the age of 35. The younger the age of the egg, the more likely it is to result in a baby. However, according to the National Institutes of Health (NIH), patients see the greatest cost-effective benefit of freezing eggs at age 37, and the least cost-effective benefit if they are younger than 30.

Cost of cryopreservation

Cryopreservation and IVF can be expensive, and paying for your fertility treatment can be a concern. One “session” or “cycle” can cost between $5,000 and $10,000. Depending on where you live and who your employer is, however, you may have coverage. To understand the full costs to you, contact your health insurance company. Mass General Brigham makes every effort to make sure that care is accessible to and affordable for everyone.

Advances in cryopreservation research

“As a part of Mass General Brigham, we have a highly specialized team of clinicians doing cutting-edge research to improve outcomes in cryopreservation,” says Dr. Dimitriadis.

Recent research highlights in fertility medicine at Mass General Brigham include ultrafast embryo thawing (essentially the reverse of flash-freezing), and utilizing artificial intelligence (AI) to streamline and improve aspects of the freezing and thawing process.

Safety and success rates of freezing eggs and embryos

Overall success rates for IVF depend on many unique factors in each case. Dr. Dimitriadis notes, however, that studies show no difference in the rates of birth abnormalities of babies born from frozen eggs versus fresh eggs. Today, these advances have created a modern family planning environment that’s never been more optimistic.

“Our team is dedicated to helping you achieve your family-building goals, in a way most comfortable to you,” says Dr. Dimitriadis. “It is our privilege to support you throughout the entire fertility journey, be it the physical or emotional aspect of this process.”

Irene Dimitriadis, MD


Infertility Specialist