Fertility Preservation Before Medical Treatment

If you are facing treatment that may affect your fertility, the single most important thing is timing. Preservation has to happen before treatment starts, and once chemotherapy or pelvic radiotherapy has begun the options narrow sharply. Raise it at diagnosis, even if you are unsure whether you want children, because deferring the conversation forecloses it. The main options are freezing eggs, sperm or embryos, and the American Society for Reproductive Medicine committee opinion on fertility preservation in patients with medical indications covers the medical indications in detail.

Whose fertility is at risk?

• Cancer treatment. Chemotherapy and radiotherapy can damage eggs and sperm. The degree depends on the drugs, the dose and the field treated, so ask your oncologist what your specific regimen is expected to do.
• Surgery involving the reproductive organs, including ovarian surgery, which can reduce the remaining egg supply.
• Some autoimmune conditions and their treatments.
• Gender-affirming treatment, where preservation is generally discussed before hormone therapy or surgery.
• Genetic conditions associated with early loss of ovarian function.

What are the options?

Sperm freezing

The simplest and quickest. A sample is produced, processed and stored in liquid nitrogen, and it can usually be arranged within days. For men facing cancer treatment this is rarely a reason to delay starting therapy. Where no sperm is present in the ejaculate, it may be possible to retrieve it surgically through TESA, PESA or TESE.

Egg freezing

Egg freezing requires a stimulation cycle, so it takes roughly two weeks. That timing is the main practical constraint, and whether it is feasible depends on how urgently treatment must begin. It requires no partner or donor sperm, so it leaves future decisions open. Our article on what egg freezing involves covers the process.

Embryo freezing

The same stimulation cycle, but the eggs are fertilized before freezing. It requires sperm at the point of freezing, and stored embryos generally require the consent of both parties for later use. Our article on egg freezing or embryo freezing compares them.

Ovarian tissue freezing

Ovarian tissue is removed surgically and frozen for later reimplantation. Its particular value is that it does not require a stimulation cycle, so it can be done without delaying urgent treatment, and it is the option available before puberty. Availability differs between centers, so ask whether it is offered where you are being treated.

Why timing matters so much

Eggs and sperm are damaged by treatment as it happens. Preserving beforehand stores cells that have not been exposed; afterwards, whatever damage has occurred is already done and may not be reversible.

This is why fertility preservation should be raised at diagnosis rather than after treatment is planned. If your treating team has not mentioned it, ask. Being told there is no time is a real answer in some cases, but it should be an answer you have actually received rather than an assumption.

We at Millennium IVF Clinic can discuss preservation options, and cases before cancer treatment are time-critical. You can contact our team.

Frequently asked questions

Does egg freezing delay cancer treatment?

A stimulation cycle takes about two weeks. Whether that delay is acceptable is a decision for your oncologist alongside the fertility team. Sperm freezing takes far less time, and ovarian tissue freezing does not require a stimulation cycle.

Can I preserve fertility after chemotherapy has started?

Options are much more limited, and any cells collected have already been exposed. This is why the conversation belongs at diagnosis.

Will I definitely be infertile after treatment?

No. It depends on the treatment, the dose and your age. Some people retain fertility. Preservation is insurance against an outcome that is uncertain rather than certain.

How long can material be stored?

Storage in Thailand is governed by the Protection of a Child Born by Medically Assisted Reproductive Technology Act B.E. 2558 (2015), which delegates the storage period to the Medical Council of Thailand rather than fixing one in the Act. Ask us what period applies and what you need to sign. Note that section 41 prohibits importing or exporting sperm, eggs or embryos, so material stored here cannot be moved abroad.