A cancer diagnosis changes priorities overnight.

When chemotherapy, radiotherapy or surgery needs to begin quickly, future fertility may understandably feel secondary to immediate cancer treatment.

However, some cancer treatments can permanently affect eggs, sperm or reproductive organs.

For this reason, fertility preservation should ideally be discussed as early as possible and, when feasible, before treatment begins.

Why Can Cancer Treatment Affect Fertility?

The effect depends on:

• Type of cancer
• Age
• Chemotherapy agents
• Dose
• Radiation location and dose
• Surgery
• Baseline ovarian or testicular function

Not every cancer treatment causes infertility.

An individualised assessment is therefore essential.

Fertility Preservation for Men

Sperm Freezing

For post-pubertal males who can produce a semen sample, sperm cryopreservation is usually the most established fertility-preservation option.

Ideally, sperm is collected before chemotherapy or radiotherapy begins.

More than one sample may be stored when time permits.

What If No Sperm Are Present in the Ejaculate?

In selected circumstances, surgical sperm retrieval may be considered.

This requires coordination between fertility specialists, andrology services and the oncology team.

Fertility Preservation for Women

Egg Freezing

Women may undergo ovarian stimulation followed by egg collection.

Mature eggs are frozen using vitrification and stored for potential future use.

Modern stimulation protocols can often begin without waiting for a particular point in the menstrual cycle, helping minimise delays to cancer treatment.

Embryo Freezing

Where appropriate, eggs can be fertilised before freezing, creating embryos for future use.

Whether egg or embryo freezing is preferred depends on individual circumstances and preferences.

Ovarian Tissue Cryopreservation

In selected patients, ovarian tissue can be surgically removed and frozen.

This may be particularly relevant when there is insufficient time for conventional ovarian stimulation or in specific younger patients.

It is a specialised procedure and requires careful assessment.

How Long Does Egg Collection Delay Cancer Treatment?

This is one of the most important practical questions.

Contemporary fertility-preservation protocols can often be organised rapidly.

However, the oncology team must determine whether there is sufficient time and whether any delay is medically acceptable.

Fertility treatment should never proceed in isolation from cancer management.

Hormone-Sensitive Cancers

Patients with hormone-sensitive cancers require particularly careful planning.

Modified stimulation strategies may be considered in some circumstances.

The fertility specialist and oncologist should work together to determine an appropriate approach.

What About Ovarian Suppression During Chemotherapy?

Medications that temporarily suppress ovarian function during chemotherapy may be considered in selected women.

However, the role of ovarian suppression and established fertility-preservation methods should be discussed carefully.

Patients should not assume that an injection given during chemotherapy provides the same reproductive opportunity as storing eggs or embryos.

Fertility After Cancer Treatment

Some patients retain or recover reproductive function following treatment.

Others experience reduced ovarian reserve, premature ovarian insufficiency or impaired sperm production.

Menstrual periods returning after chemotherapy do not necessarily mean fertility has returned completely.

Likewise, absence of menstruation does not provide all the information needed to assess future reproductive options.

Post-treatment fertility assessment may therefore be useful.

Pregnancy After Cancer

Many cancer survivors later have successful pregnancies.

The appropriate timing depends on the cancer diagnosis, treatment, recurrence risk, medications and overall health.

This decision should involve the oncology and fertility teams rather than applying a single waiting period to every patient.

Fertility Preservation Is About Choice

Not every patient who freezes eggs, sperm or embryos will eventually use them.

That does not mean preservation was unnecessary.

At the time of a cancer diagnosis, fertility preservation can protect a future reproductive option that might otherwise be lost.

The Take-Home Message

Cancer treatment should remain the immediate priority, but future fertility deserves consideration whenever treatment may affect reproductive function.

Early referral is critical because fertility-preservation options are usually greatest before chemotherapy, radiotherapy or fertility-impacting surgery begins.

Women may have options including egg, embryo or ovarian tissue cryopreservation. For men, sperm freezing is usually the first-line approach.

Rapid communication between oncology and fertility teams can allow patients to receive appropriate fertility counselling without unnecessarily delaying essential cancer treatment.

The goal is simple: wherever medically possible, treating cancer today should not prevent patients from understanding and protecting their reproductive choices for tomorrow.