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Fertility Preservation

  • The freezing of embryos, eggs, ovarian tissue, sperm, or testicular tissue for future reproduction
  • For people who are concerned about future fertility
  • Age, health conditions, cancer therapy, and transgender care are reasons to consider this treatment
  • Involves Yale Fertility Center, Yale Medicine Urology

Fertility Preservation


Less than a generation ago, fertility preservation was the stuff of science fiction, but so much has changed in recent years. Modern technologies have caught up with modern lifestyles. 

Highly successful fertility preservation methods are now available to cancer patients hoping to conceive in the future as well as women who have put off starting a family due to partnering later in life or pursuing a demanding career.

"Fertility preservation is a new branch of reproductive medicine which was started about 20 years ago and has now grown into a well-established practice, says Pasquale Patrizio, MD, director of the Yale Fertility Center's Fertility Preservation Program. "We have a true comprehensive practice. Besides offering the entire spectrum of treatments available for fertility preservation, we are constantly exchanging information about new protocols and treatments with our colleagues and experts, which allows us to quickly implement any new methods or changes." 

What is fertility preservation?

Fertility preservation is the practice of proactively helping patients to preserve their chances for future reproduction.

What factors may lead to fertility preservation?

Fertility can be compromised for many reasons, says Dr. Patrizio. 

"Age is definitely a factor as many women are postponing childbirth because of a career or because they haven't met the right companion and therefore they can freeze eggs for future use," he says. 

At birth, each female has about 1 million oocytes. But, as she ages, the number of eggs steadily decreases. At puberty, the residual egg number is approximately 400,000. Fertility decreases sharply after 37 and by age 40 or older, the chances of pregnancy diminish significantly because both the number and the quality of the eggs are reduced.

But the most common reason patients come to Yale Medicine Fertility Center for fertility preservation, Dr. Patrizio says, is cancer—most often for breast cancer, followed by lymphomas (Hogdkin and non-Hogdkin).

Cancer itself can affect reproductive organs or the damage to the ovaries and testis can be caused by the type, and dose of chemotherapy or radiotherapy. Given the effective treatment protocols for cancer, the majority of patients will survive their disease, which makes it crucial to preserve future fertility options from the potential toxic effect of the chemo or radiotherapy.

Risk factors contributing to consider fertility preservation include:

  • Chemotherapy: Reproductive organs, especially ovaries, are extremely sensitive to treatments such as chemotherapy. Certain drugs can cause ovarian or testicular damage. In addition to killing cancer cells, these drugs may also kill egg and sperm cells.
  • Radiation therapy: This treatment uses high-energy X-rays, gamma rays and/or charged particles to damage the DNA of cancer cells. If the radiation site is near reproductive organs, it may affect fertility. Total body irradiation, in preparation for bone marrow transplants also affect fertility.
  • Surgery: Surgical removal of the reproductive organs may make it difficult or impossible for a woman to get pregnant unless they cryopreserve oocytes, embryos and then potentially resorting to gestational surrogacy to carry a baby to term. A man undergoing removal of a testis or prostate for cancer should freeze sperm before surgery and treatment to preserve the chances to father children in the future.
  • Late childbearing: American women are waiting longer and longer to start their families. The average age for first births rose from 21.4 in 1970 to 26 in 2013. It is increasingly common for first births to occur past the age of 35. As a woman's fertility decreases with each passing year, many consider fertility preservation in the hope that they will be able to start families in their late 30s, 40s.
  • Autoimmune diseases: Certain autoimmune diseases such as rheumatoid arthritis can harm a woman or man's fertility.
  • Transgender individuals: At Yale Medicine, we work with men transitioning to women wishing to preserve sperm, or we can preserve eggs for women transitioning to men. 

When is it time to discuss fertility preservation with my doctor?

Patients should discuss fertility preservation with their physician as soon as it might become clear that the plan of care may involve any of the risk factors listed above. This goes for both men and women. Fertility treatments take time and planning, and it may be necessary to coordinate treatment with other medical teams.

What kinds of treatments are used to preserve fertility?

At Yale Medicine Fertility Center, we offer several options for women and men. These include:

  • Embryo cryopreservation: With this procedure, the patient goes through a cycle of in-vitro fertilization, which starts by stimulating the ovaries to develop multiple eggs, harvest them and then combining it with sperm cells to create embryos. The embryos are then treated with cryoprotectant agents to prevent damage by ice crystals during cryopreservation.
  • Oocyte cryopreservation (Egg freezing): For this procedure, patients undergo ovarian stimulation to develop multiple eggs that once extracted are cryopreserved. This procedure is relatively new, but pregnancy rates of patients using frozen oocytes are now approaching those using frozen embryos. In 2012 the American Society of Reproductive Medicine established that this procedure should no longer be considered experimental. Yale Medicine is proud to have been at the forefront of this success story.
  • Ovarian tissue cryopreservation: Some patients don’t have time to wait. They need immediate treatment due to a pelvic cancer or a sarcoma. In these cases, the only option is to cryopreserve ovarian tissue. Using a minimally invasive technique, the physician removes the ovarian cortical tissue where eggs are located. This tissue can then be frozen until the patient needs it.
  • Auto-transplantation of ovarian tissue: Once cancer treatment is over and the patient wants to start a family, the patient’s own frozen ovarian tissue can be thawed and restored to the patient’s body. It may be placed on the remaining ovary or in the pelvic side wall. Ovarian function may return within four to months of this process.
  • Sperm cryopreservation: The Yale Medicine Fertility Center also offers help to men who need to consider fertility preservation. Men may choose to provide a sperm sample for cryopreservation In some cases, Yale doctors may take sperm directly from the testis with a testicular biopsy. The Yale Medicine team can then cryopreserve the sperm, in a process similar to that for eggs and embryos. The sperm can then be held long-term until the patient is ready for fatherhood.

At this time, many of these treatments are not widely covered by health insurance companies. In Connecticut, many insurance plans cover embryo freezing that is part of in vitro fertilization. And, insurance companies are now required to cover fertility preservation treatment for male and female cancer patients age 40 and under.

What makes Yale Medicine's approach to fertility preservation unique?

Everything practiced at the Yale Medicine Fertility Center is to help our patients achieve their dreams of having a family on the timeline that works for them.

"I enjoy helping people create families and being there for them. This is a vulnerable population and they need compassion and understanding," Dr. Patrizio says. "To treat these couples, you need to be a reproductive endocrinologist, but also a bioethicist and psychologist. A lot is spoken and unspoken between couples at consultations and it is very important that we listen and offer them the strongest possible support aided by social workers."

Furthermore, we are working to further connect with oncologists to refer patients to us. To that end, we have a Fertility Preservation Center at the Smilow Cancer Hospital at Yale New Haven where patients can receive immediate consultation and information about fertility and the various options for fertility preservation. 

Our fertility specialists are also researchers, constantly advancing the field, especially in the area of cryopreservation and the preservation of ovarian follicles and tissue.