How treatment can affect fertility

Cancer treatments can affect fertility in different ways:

  • Chemotherapy can affect the ovaries. It can cause fewer or no eggs to be produced. Chemotherapy can have a temporary or permanent effect on fertility.
  • Radiotherapy can affect egg production. It can also damage the ovaries or womb, and reduce hormone levels. Different types of radiotherapy have different effects on fertility.
  • Surgery to your womb, ovaries or pituitary gland can affect your fertility.
  • Hormonal therapy reduces or blocks the hormones in your body. The effects on fertility are usually temporary.
  • Targeted therapies may have an effect on fertility but not much is known about this yet.

Changes to fertility are permanent for some women, but temporary for others. Your doctor will be able to talk to you about any possible fertility risks with your treatment. You can speak to your doctor about having your fertility tested after you finish cancer treatment.

It is important to use contraception during cancer treatment as treatments could harm a developing baby.

Cancer treatments and fertility

The main  treatments for cancer are chemotherapy, radiotherapy, surgery, hormonal therapy and targeted therapy. These treatments affect fertility by:

  • damaging the eggs or ovaries
  • affecting hormone production
  • altering or removing the womb.

Chemotherapy and fertility

Chemotherapy affects the way the ovaries work and can result in fewer or no eggs being produced. Your periods may become irregular or stop for a while (temporary infertility). It may take up to two years for them to come back again. Chemotherapy sometimes causes permanent infertility and brings on an early menopause. The risk of infertility often depends on:

  • Your age – younger women are more likely to remain fertile and their periods usually come back. Women over 35 already have a lower chance of getting pregnant as the number and quality of the eggs has started to decline naturally. The older you are, and the closer you are to your natural menopause, the higher the risk of infertility.
  • The drugs you have – some chemotherapy drugs, for example cyclophosphamide and chlorambucil, have a higher risk of causing infertility. Some drugs have a medium risk (doxorubicin and cisplatin) and others have little or no risk (vincristine and methotrexate). We have more information about individual chemotherapy drugs.
  • The dose – higher doses of chemotherapy, especially before stem cell transplants, are more likely to affect fertility.

In some cases, it may be possible to choose a chemotherapy treatment that’s less likely to affect fertility. Your cancer specialist will explain if this is an option for you.

Chemotherapy can reduce the number of eggs you have. So even if your periods do come back, your menopause may start 5–10 years earlier than usual. This means you have a shorter time to try to get pregnant.

Radiotherapy and fertility

Radiotherapy treats cancer by using high-energy rays to destroy cancer cells. It can have an effect on a woman’s fertility by:

  • affecting egg production
  • damaging the ovaries or womb
  • reducing hormones (oestrogen and progesterone).

Radiotherapy to the pelvis

Radiotherapy given directly to the ovaries or the womb will cause permanent infertility. Radiotherapy to the pelvic area may indirectly damage the ovaries or the womb. This may stop the ovaries from working or cause an increased risk of miscarriage or premature birth if the womb lining is damaged.

It may be possible to protect the ovaries with a lead shield when radiotherapy is given close to the ovaries. Occasionally, surgeons can do a minor operation to move the ovaries out of the way to protect them from the radiation. This is called ovarian transposition and can be done by keyhole surgery.

Your risk of infertility depends on the dose of radiotherapy you have and your age – the risk increases as you get older. There’s a higher risk of infertility when you have both radiotherapy and chemotherapy.

Total body irradiation (TBI)

TBI is radiation given to the whole body before a donor stem cell or bone marrow transplant. This usually causes permanent infertility.

Radiotherapy to the brain

Radiotherapy to the pituitary gland at the base of the brain can sometimes affect fertility. The pituitary gland controls the hormones (gonadotrophins) which make the ovaries produce oestrogen and progesterone.

If your pituitary gland has been affected, you can be given gonadotrophin injections to help you get pregnant.

Other types of radiotherapy

Radiotherapy to areas of the body that we haven’t mentioned here won’t cause infertility.

Surgery and fertility

Operations that can affect fertility are:

  • having your womb removed (hysterectomy)
  • having your ovaries removed
  • surgery to the pituitary gland.

Surgery to the womb or ovaries

For some cancers, surgery can involve removing the womb (hysterectomy), the ovaries or both.

Occasionally women with a very small, early cancer of the cervix can have an operation called a trachelectomy. This operation removes most of the cervix but leaves the womb. It may then be possible to become pregnant and have a baby afterwards. This is a specialised operation and it’s only done in a few hospitals by very experienced surgeons.

Young women with germ cell tumours of the ovary may sometimes have only the affected ovary removed to preserve their fertility.

Women who have both ovaries removed may be able to have eggs or fertilised eggs (embryos) frozen before surgery. Having your eggs collected may mean delaying the start of your cancer treatment, so it may not always be possible.

Women who have their womb removed may still have fertility options. This involves a surrogate (a woman who carries the baby in her womb for you).

Surgery to the pituitary gland

Surgery may be used to remove a tumour in the pituitary gland at the base of the brain. The pituitary gland controls the hormones (gonadotrophins) that make the ovaries produce oestrogen and progesterone.

Surgeons try to remove the tumour while leaving some of the pituitary gland. But this is not always possible, and in some cases the whole gland needs to be removed.

This can affect the hormones (gonadotrophins) that stimulate the ovaries. This can make you menopausal – not because you have run out of eggs but because your ovaries aren’t being stimulated to release them.

Gonadotrophin injections can be given to stimulate your ovaries to start producing eggs again.

Hormonal therapy and fertility

Hormonal therapy reduces the levels of hormones in the body or blocks their effect on cancer cells. It is usually used to treat breast cancer. Hormonal therapy can affect your fertility but any effects are usually temporary. The drugs commonly used are tamoxifen and goserelin (Zoladex®).

Zoladex will stop your periods, but they usually come back again about six months after you stop taking it. But if you’re close to your natural menopause, your periods may not come back.

Tamoxifen can make your periods irregular or stop, but they usually start again a few months after you’ve finished taking it. However, taking tamoxifen can also increase your fertility, so it’s important to use effective contraception during treatment as there’s a risk it may harm an unborn baby. Tamoxifen is often taken for at least five years, which may be a concern if you want to get pregnant sooner. You can talk about any concerns with your cancer doctor.

Some women go through their natural menopause while taking hormonal therapy. You may not be aware of this because the side effects of hormonal therapy are similar to the symptoms of the menopause.

Targeted therapies and fertility

Targeted therapies are a newer type of cancer treatment. It’s not yet known exactly what effect they have on fertility. However, the drug bevacizumab (Avastin ®) is known to increase the risk of infertility.

If you’re taking a targeted drug, you will be advised not to get pregnant during treatment and for a while after. Talk to your cancer doctor about this.

Contraception during cancer treatment

It’s important to use effective contraception during cancer treatment to avoid getting pregnant. This is because the treatments may harm a developing baby. Even if your periods stop during treatment, this doesn’t mean you can’t get pregnant as they could start again.

If you’ve had breast cancer, your doctor will advise you not to take the contraceptive pill or use a medicated coil (IUD) which contains hormones. This is because they could encourage breast cancer cells to grow. Your cancer doctor or specialist nurse will give you more advice about this.

After treatment

There is no evidence that cancer treatments harm children that you have after treatment. But doctors usually advise you to carry on using contraception for about a year after treatment.

Some women may be advised to wait up to two years after treatment before trying to get pregnant. This is because if a cancer is going to come back, it’s often within this time. If you’re thinking of getting pregnant it’s a good idea to talk to your cancer doctor first.

Getting your fertility tested

You might decide to have tests done after your cancer treatment is finished to check your fertility. Women who have had cancer treatment are usually referred for testing after six months of trying to get pregnant. This is because of their risk of early menopause.

Your doctor will ask you about your periods and take some blood tests. These tests can show how many eggs you have left in your ovaries (ovarian reserve) or how close to your menopause you are. Taking the contraceptive pill or hormone replacement therapy (HRT) can affect the results of these tests. Let your doctor know if you’re taking either of these.

If you are having periods, you can have a blood test to measure a hormone called follicle stimulating hormone (FSH). This can only be done on certain days in your menstrual cycle as FSH levels change during the month. Another test can measure anti-Mullerian hormone (AMH). This can be done at any time in the menstrual cycle and even if you’re not having periods.

Some women’s periods can come back months or years after cancer treatment. This is more likely if you’re younger but it also depends on the treatment you’ve had. If your periods change, you can have these tests repeated. Your fertility specialist will talk to you about the options available to you.

Back to Fertility in women

Getting support

Many women find it helpful to talk to family, friends, counsellors or other women in similar situations when coping with infertility.