Chemotherapy uses drugs to kill or slow the growth of cancer cells. These drugs travel throughout the body and are designed to affect fast-growing cells such as cancer cells. This means they can also damage other cells that grow quickly, including in the ovaries.

If treatment reduces the total number of eggs, there is a high risk of infertility. The risk depends on:

• the drugs used – some types of chemotherapy drugs are more likely to damage eggs than others
• the dose you are given – the risk of damage to eggs increases with higher doses and longer treatment times
• your age – the number and quality of eggs decrease with age.

Having chemotherapy can cause your periods to become irregular or even stop for a while, but they often return to normal within a year of finishing treatment. If your periods do not return, the ovaries may have stopped functioning permanently, causing early menopause.

Some chemotherapy drugs can affect your heart and lungs. If this causes long-term damage, it may make a future pregnancy and delivery more difficult. Your specialist will talk to you about what precautions to take during pregnancy.

Radiation therapy uses a controlled dose of radiation to kill cancer cells or damage them so they cannot grow and multiply. It can be delivered from inside or outside the body. The risk of infertility will vary depending on the area treated, the dose of radiation and the number of treatments.

• Radiation therapy to the pelvic area (for cancer of the rectum, bladder, cervix, uterus or vagina) can stop the ovaries producing hormones. This results in temporary or permanent menopause. If your ovaries don’t need treatment, one or both may be surgically moved higher in the abdomen and out of the field of radiation. This is called ovarian transposition or relocation (oophoropexy), and it may help the ovaries keep working properly.
• Radiation therapy to the pelvic area can also affect the uterus, make sexual intercourse uncomfortable, and increase the risk of miscarriage, premature birth and low birth weight.
• Radiation therapy to the brain may damage the pituitary gland, which releases hormones that tell the ovaries to release an egg each month. This may affect ovulation.

If you are treated with both chemotherapy and radiation therapy (chemoradiation), the risk of infertility is higher. 

Surgery that removes part or all of the reproductive organs, such as the ovaries, fallopian tubes, uterus and cervix, can cause infertility.

Removal of the ovaries (oophorectomy) – if both ovaries are removed (bilateral oophorectomy), you will experience early menopause. You will no longer have periods or be able to become pregnant naturally. If only one ovary is removed, the other should continue to release eggs and produce hormones. You will still have periods and may be able to become pregnant if you still have a uterus.

Removal of the uterus and cervix (hysterectomy) – this may be used to treat gynaecological cancers, such as cancer of the cervix, ovary, uterus and endometrium (lining of the uterus), and sometimes, cancer of the vagina. After a hysterectomy, you will be unable to carry a pregnancy and your periods will stop. As your ovaries will continue to function, you may be able to fertilise your eggs through IVF and use a surrogate to carry the pregnancy.

The hormones oestrogen or progesterone may help some types of breast and uterine cancers to grow. Hormone therapy aims to slow down the growth of these cancers by lowering the amount of hormones the tumour receives.

Hormone therapy can be used for a short time or long term. As it blocks the hormones that are required for fertility, you will have to wait until hormone therapy is finished to try for a baby. You may be able to store eggs or embryos before starting hormone therapy.

Anti-oestrogen drugs are used to reduce the risk that oestrogen-sensitive breast cancers will come back after treatment. Many anti-oestrogen drugs are taken for several years. During this time, pregnancy should be avoided, as there is a risk the drugs could harm an unborn child. These drugs do not cause infertility and do not damage the ovaries or eggs. Although hormone treatments for breast cancer are used for many years, it is often possible to take a break from the drugs to try for a baby.

If you are on hormone therapy and want to become pregnant, talk to your treatment team or fertility specialist about the advantages and disadvantages of stopping hormone therapy.

Stem cell transplant – high-dose chemotherapy and, possibly, radiation therapy are given before the transplant to kill the cancer cells in the body. The risk of permanent infertility after high-dose chemotherapy or radiation therapy is high.

Immunotherapy and targeted therapy – the effects of these newer drugs on fertility and pregnancy can vary depending on the drug you take. It is important to discuss the potential impact of these drugs with your cancer or fertility specialist.

Most menopause symptoms are related to a drop in your body’s oestrogen levels. Menopause symptoms are usually more severe when menopause starts suddenly because the body hasn’t had time to get used to the gradual decrease in hormone levels. Symptoms may include:

• a dry or tight vagina
• a decreased interest in sex (low libido)
• hot flushes and night sweats
• aching joints
• trouble sleeping
• dry or itchy skin
• feeling more anxious or overwhelmed.

For more information, talk to your doctor or ask for a referral to a specialist menopause clinic.

Osteoporosis – early menopause can cause the bones to weaken (osteoporosis). Talk to your doctor about having a bone density test or taking medicines to prevent your bones weakening. Regular weight-bearing exercise will help keep your bones strong.

Hot flushes, dry vagina and poor sleep – menopause hormone therapy (MHT, previously known as hormone replacement therapy) may help treat these symptoms. MHT replaces the hormones usually produced by the ovaries, and can be taken as tablets, creams or skin patches. Taking MHT may increase the risk of some diseases. Some women with a hormone-sensitive cancer may be advised not to take MHT, but there are other non-hormonal drugs available that can help. Vaginal moisturisers available over the counter can also help with vaginal discomfort and dryness.

Anxiety – meditation and relaxation techniques can help reduce stress and lessen anxiety. Cognitive behaviour therapy (CBT) has been shown to be effective in helping women deal with many of the effects of menopause, including anxiety. Exercise can also help with mood changes and energy levels.

When cancer treatment causes early menopause, the impact on your emotions, body image and relationships can be significant.

If you are younger, experiencing menopause much earlier than expected may affect your sense of identity, or make you feel older than your age or friends. You may feel less feminine and worry that you are less attractive.

If you are older, going through menopause earlier than expected may be upsetting. But some older women say they feel relieved not having to worry about regular periods. You may find it difficult to start new intimate relationships after going through menopause.

It may take time to accept the changes you’re experiencing. Talking to a family member, friend or counsellor may help. You can also call our cancer nurses on 13 11 20 for emotional support.