Egg Freezing Before Cancer Treatment

Egg freezing is also called oocyte cryopreservation. Hormone shots make several eggs ripen at once. A doctor collects those eggs, the lab cools them very fast, and they sit in storage. Years later they can be thawed, fertilized with sperm, and transferred into a uterus.

The reason to do this before cancer treatment is blunt. You are born with all the eggs you will ever have, and cancer treatment can destroy them. Alkylating drugs carry high risk. This chemotherapy family includes cyclophosphamide. These drugs can stop the ovaries from making mature eggs and estrogen. Doctors call that primary ovarian insufficiency: the ovaries shut down years early. Radiation aimed at the pelvis can damage or destroy eggs directly.

Doing it afterward is not a safe backup plan. No one has set a safe waiting time between the end of chemotherapy and egg or embryo freezing.

Budget about two to three weeks from your first fertility clinic visit to the egg retrieval.

You inject hormones for roughly 7 to 12 days so that many follicles grow together. A follicle is the small fluid sac in the ovary that holds one egg. During those days you return to the clinic often. You get blood tests and a transvaginal ultrasound, which uses a probe placed in the vagina. Your dose is adjusted from what those show.

The retrieval itself is an outpatient procedure under sedation. Guided by ultrasound, the doctor passes a thin needle through the vaginal wall into each ovary and draws out the fluid that holds the eggs.

The lab freezes the mature eggs by vitrification. This method cools them so fast that damaging ice crystals never form. This is the step that made egg freezing work. Thawed eggs now give pregnancy and live birth rates close to fresh ones. Survival after thawing runs near 95% for eggs frozen before age 36 and near 85% at 36 and older.

Older stimulation protocols started on a set day of the menstrual cycle. Waiting for that day could cost weeks, which some cancers do not allow. Clinics now use random start, also called immediate start, and begin stimulation on whatever cycle day you arrive. Reviewed evidence finds these cycles cause little or no delay. Embryo and pregnancy results are similar. If a clinic tells you to wait for a period, ask whether random start is on the table.

Three different things can be frozen, and they suit different people.

Frozen eggs are yours alone. No sperm is needed on retrieval day, and no one else holds a claim on them later.

Frozen embryos are eggs already fertilized in the lab. One way mixes egg and sperm in a dish, which is standard in vitro fertilization (IVF). The other injects a single sperm into one egg, called IVF-ICSI. Embryos need a partner's or donor's sperm at the time of retrieval, and both people share control of them afterward.

Ovarian tissue freezing skips stimulation completely. A surgeon removes part or all of one ovary through laparoscopy, which uses small cuts in the belly. The lab slices that tissue into strips and freezes them. This is the route for girls before puberty and for anyone whose treatment cannot wait even two weeks. It is no longer labeled experimental. After frozen tissue is put back, more than 70% of patients regain ovarian function. It returns about 19 weeks later on average and lasts roughly 2.5 years. In one review, 69% of pregnancies after transplant happened without any assisted reproduction.

Ovarian transposition, or oophoropexy, is a different tool for a different threat. A surgeon moves the ovaries above and to the side of the pelvis so radiation misses them. How well it protects depends heavily on age. In one retrospective study, 71.2% of patients aged 30 or older went through menopause after treatment, compared with 26% of those under 30.

Stimulation pushes estrogen levels up. That worries anyone with estrogen receptor-positive breast cancer, meaning a tumor that grows in response to estrogen. The standard fix is to give letrozole during the stimulation cycle. Letrozole is an aromatase inhibitor, a drug that blocks the body from making estrogen. Studies of stimulation with letrozole have found no difference in recurrence or disease-free survival. The same approach is used for people who carry a BRCA gene mutation.

A separate drug class does something else entirely. Gonadotropin-releasing hormone agonists, such as goserelin, shut the ovaries down during chemotherapy. They stop the ovaries making estradiol, a form of estrogen. These may be offered in breast cancer to lower the risk of primary ovarian insufficiency. They do not replace frozen eggs or embryos. Say so if the two are offered as equal choices.

Ask this out loud. The honest answer changes sharply with age.

With 10 mature frozen eggs, the modeled chance of at least one live birth is about 69% at age 35 or younger, 45% at 38, 30% at 40, and 20% at 42. To reach roughly a 70% chance, the modeled counts are about 10 eggs at 35 or younger, about 20 at 38, about 35 at 40, and about 55 at 42.

Those are models, not guarantees. But they explain why a clinic may push for a second retrieval cycle when your cancer timeline allows one. They also explain why it drops the idea when the timeline does not.

Stimulation can overshoot. Ovarian hyperstimulation syndrome (OHSS) makes the ovaries swell and leak fluid into the abdomen. Mild OHSS shows up in about 20% of IVF cycles. Moderate and severe forms occur in under 5%.

Weigh yourself at the same time each day during stimulation so the number means something. Then act on what you see.

• Call 911 or go to an emergency department if you are short of breath, or belly pain turns severe and will not ease.
• Call the clinic the same day if you gain more than 2 pounds (1 kg) in one day. The same goes for belly swelling, passing much less urine than usual, dizziness, or vomiting that stops you keeping fluids down.
• Call the clinic within a day or two if mild bloating or queasiness is not settling, so they can decide whether to bring your next monitoring scan forward.

One cycle of egg or embryo freezing runs above $10,000, with estimates near $12,000, and that is before yearly storage fees. As of January 2023, only 12 states required insurers to cover fertility preservation that is medically indicated. That means it was ordered because a treatment threatens fertility.

Ask the fertility clinic's financial counselor for three specific things: the itemized quote for one cycle, the annual storage fee after that, and the billing codes they will submit. Ask your oncologist's office to put the words "medically indicated fertility preservation" in the referral. Coverage rules turn on that phrase.

Ask your oncologist how many days the plan can safely wait. Get that answer before the fertility clinic builds a schedule around a guess.

Read what the clinic's consent form says about who controls stored eggs or embryos later. Ask what happens if a relationship ends. Eggs and embryos are not handled the same way.

Confirm who is sending records between the two clinics. The fertility team needs your diagnosis, hormone results, and treatment start date to design the cycle.

https://www.cancer.gov/about-cancer/treatment/side-effects/fertility-women https://www.cancer.org/cancer/side-effects/fertility/preserving-fertility-in-women.html https://pmc.ncbi.nlm.nih.gov/articles/PMC10218997/ https://www.asrm.org/practice-guidance/practice-committee-documents/fertility-preservation-in-patients-with-medical-indications-a-committee-opinion-2026/ https://medlineplus.gov/ency/article/007294.htm