Fertility preservation is any medical procedure that protects your ability to have biological children in the future. It works by collecting and freezing eggs, sperm, embryos, or reproductive tissue before something that could damage your fertility, whether that’s cancer treatment, hormone therapy, or simply the passage of time. The frozen material is stored in liquid nitrogen and can remain viable for decades.
Who Benefits From Fertility Preservation
The most urgent cases involve cancer. Chemotherapy and radiation can permanently damage eggs and sperm, so the American Society of Clinical Oncology recommends that fertility preservation be discussed before cancer-directed therapy begins. Even a single round of treatment can compromise sperm DNA integrity, and certain chemotherapy regimens carry more than a 50% risk of causing permanent ovarian failure in women.
But cancer is far from the only reason. People pursue fertility preservation when they have autoimmune diseases like lupus that require treatments toxic to reproductive cells, endometriosis or uterine fibroids that may worsen over time, genetic conditions that affect fertility, or exposure to toxic chemicals through work or military service. A growing number of people freeze eggs or sperm simply because they want to delay having children, sometimes called “social freezing” or elective preservation.
Transgender individuals also have a significant stake in fertility preservation. Testosterone therapy suppresses ovulation and can alter ovarian tissue, while estrogen therapy can impair sperm production and cause testicular changes. The effects are variable: some studies show complete cessation of sperm production after estrogen therapy, while others show preserved function. But among people who continued hormone therapy without stopping, some became completely unable to produce sperm, whereas those who discontinued hormones before banking had semen parameters within normal limits. For this reason, the World Professional Association for Transgender Health, the Endocrine Society, and several other major organizations recommend counseling on fertility preservation before starting hormone therapy or puberty-suppressing medications.
Options for Freezing Eggs and Embryos
Egg freezing (oocyte cryopreservation) involves hormone injections over roughly two weeks to stimulate the ovaries to produce multiple eggs, which are then retrieved in a short outpatient procedure and frozen. Embryo freezing follows the same initial steps but adds fertilization with sperm before the resulting embryos are frozen. Both processes typically take two to three weeks from start to finish, a timeline that matters when treatment for cancer or another condition is waiting.
The two approaches produce comparable results. Live birth rates are essentially identical: about 25% per transfer cycle for both frozen eggs and frozen embryos. Clinical pregnancy rates are also similar, around 26–30%. The key difference is at the thaw stage. Embryos survive the freezing and thawing process at a higher rate than unfertilized eggs (90% vs. 79%), so you may need to freeze more eggs to end up with the same number of usable specimens. On the other hand, one study found a lower miscarriage rate with thawed eggs (1.5%) compared to thawed embryos (8.1%), and perinatal outcomes like birth weight and gestational age were not significantly different between the two.
The practical distinction often comes down to life circumstances. Freezing embryos requires sperm at the time of freezing, meaning you either have a partner or use donor sperm. Freezing eggs preserves more flexibility because you haven’t committed to a sperm source yet.
How Age Affects Success
Age at the time of egg freezing is the single biggest factor in whether those eggs will eventually produce a baby. Women under 35 need roughly 14 to 20 mature eggs for a 70–80% chance of at least one live birth. At 38, that number jumps to about 27 eggs. By 40, you’d need around 44, and at 41, approximately 55. Since each retrieval cycle yields a limited number of eggs, younger women often need just one cycle while older women may need several to bank enough.
A large study from a New York fertility center found that women under 38 who froze 20 or more eggs had roughly a 70% chance of a live birth. Women over 35 who froze at least 20 eggs had about a 50% chance. These numbers reflect the biological reality that egg quality declines with age, and no amount of freezing technology can reverse that decline once the eggs have been collected.
Sperm Freezing
Sperm cryopreservation is simpler, faster, and far less expensive than egg or embryo freezing. A sample is usually collected through ejaculation, though vibratory devices or surgical extraction are available for people who can’t ejaculate due to spinal cord injuries or other conditions. The sperm is treated with protective solutions, placed in small vials or straws, and stored in liquid nitrogen. Research shows cryopreserved sperm remains safe and effective for use in fertility treatments even after 40 years of storage.
Sperm should be collected before any cancer treatment starts. Chemotherapy and radiation can cause genetic damage to sperm, and that risk is elevated both during and shortly after treatment. Banking multiple samples when possible provides a better safety margin.
Ovarian Tissue Freezing
For people who can’t wait two to three weeks for an egg retrieval cycle, or for prepubertal girls who don’t yet produce mature eggs, ovarian tissue cryopreservation is an alternative. A surgeon removes thin strips of ovarian tissue in a minimally invasive procedure. The tissue is frozen, and when the person is ready to try for a pregnancy, the strips are transplanted back, typically onto the remaining ovary or nearby tissue. The transplanted tissue can restore both fertility and natural hormone production.
This technique has a live birth rate of about 57% after transplantation. In one study tracking 69 patients (including two who hadn’t yet started menstruating), about 39% developed premature ovarian failure after their cancer treatment, but 45% maintained normal ovarian function, and 27% became pregnant without needing their frozen tissue at all. Ovarian tissue freezing is the only established fertility preservation option for prepubertal girls facing gonadotoxic treatment and for prepubertal transgender boys considering future biological parenthood.
The Role of Vitrification
The shift from traditional slow freezing to vitrification, a rapid flash-freezing technique, has dramatically improved outcomes across all types of fertility preservation. Vitrification prevents ice crystals from forming inside cells, which is the main source of damage during conventional freezing. The results speak for themselves: embryo survival after vitrification is about 97%, compared to 83% with slow freezing. Post-thaw quality is even more striking. About 92% of vitrified embryos had all their cells intact after warming, versus only 56% of slowly frozen embryos. Vitrification is now the standard method at most fertility clinics.
Cost and Insurance Coverage
Fertility preservation is expensive, and costs vary significantly by procedure. A single cycle of egg or embryo freezing in the United States averages $10,000 to $15,000, not including annual storage fees. Sperm freezing costs roughly $745 for the first year, including storage. Most people who freeze eggs need at least one cycle, but older patients may need two or three to bank enough eggs for a reasonable chance of success, multiplying the cost accordingly.
Insurance coverage is uneven but expanding. Sixteen U.S. states now mandate some form of insurance coverage for fertility preservation, including California, Colorado, Connecticut, Delaware, Illinois, Kentucky, Louisiana, Maine, Maryland, New Hampshire, New Jersey, New York, Rhode Island, Texas, and Utah. Connecticut and Rhode Island were the first to pass such laws in 2017. Some mandates cover only medically necessary preservation (for example, before cancer treatment), while others are broader. In states without mandates, coverage depends entirely on your employer’s plan, and many plans exclude fertility services altogether.
Timing Is Critical
Across nearly every scenario, the consistent message from clinical guidelines is that fertility preservation works best when it happens before the thing that threatens fertility. For cancer patients, that means before the first dose of chemotherapy or radiation. For transgender individuals, it means before starting hormone therapy. For people freezing eggs electively, it means as young as practically possible, since every year of delay reduces egg quality and increases the number of eggs needed.
Egg and embryo freezing require about two to three weeks. Sperm banking can often be completed in a day or two. Ovarian tissue freezing requires a surgical procedure but no hormonal stimulation, so it can be scheduled quickly. If you’re facing a time-sensitive situation like a cancer diagnosis, a reproductive specialist can often coordinate preservation to avoid delaying treatment.